GENERAL PRINCIPLES OF REHABILITATION
In the past, rehabilitation was regarded as aftercare, but today, rehabilitation is recognized as an important part of the acute-care program. Physicians, therapists, and other health care workers in the field of orthopedics are involved in rehabilitation programs for a variety of patients, including those with congenital or acquired musculoskeletal problems (eg, bone deformities, arthritis, or fractures) as well as those with neurologic trauma or diseases that affect limb function (eg, spinal cord injury [SCI], stroke, or poliomyelitis). Rehabilitation in these patients frequently involves correcting limb deformities, increasing muscle strength, maximizing motor control, training individuals to make the most effective use of residual function, and providing adaptive equipment.
The most successful model for rehabilitation addresses the physical, emotional, and other needs of the patient and is based on a team approach. Among those frequently included in the team are physicians and nurses from various medical specialties, physical and occupational therapists, speech therapists, psychologists, orthotists, and social workers as well as the patient and members of the patient's family. The shared goal of team members is to prevent barriers to rehabilitation by (1) diagnosing accurately all current problems in the patient, (2) treating the problems adequately, (3) establishing adequate nutrition, (4) monitoring the patient for any complications that might impede progress in recovery, (5) mobilizing the patient as soon as possible, and (6) restoring function or helping the patient adjust to an altered lifestyle.
Management of Common Problems in Rehabilitation
Inadequate nutrition, decubitus ulcers, urinary tract infections, impaired bladder control, spasticity, contractures, acquired musculoskeletal deformities, muscle weakness, and physiologic deconditioning are common complications that can obstruct rehabilitation efforts and cause further loss of function in an already compromised patient. Because these problems are costly in both human and financial terms, every effort should be made to prevent them.
Good nutritional status is the basis for avoiding many of the previously listed complications. In trauma patients, the nutritional requirements are markedly increased from the normal maintenance requirement of 30 kcal/kg/day. Most trauma patients have been receiving intravenous fluids with minimal nutritional benefit and so arrive at the rehabilitation center in various degrees of malnutrition. Patients with chronic illnesses commonly have poor appetites. Physically handicapped people expend much of their energy performing simple activities of daily living (ADLs) and may also have difficulty in obtaining and preparing adequate amounts of food. Yet another form of poor nutrition that should be noted is obesity. Inactivity leads to diminished calorie need, but boredom may result in increased consumption.
DECUBITUS ULCERS (PRESSURE SORES)
The combination of poor nutritional status, lack of sensation at pressure points of the body, and decreased ability to move can cause decubitus ulcers (Figure 13–1) and greatly add to the length and cost of the patient's hospital stay. The ulcer is a potential source of sepsis in an already compromised individual and often requires that a flap graft be rotated to cover the defect. After a sacral flap is rotated, the patient must remain in a prone position until the graft heals. This significantly hampers the patient's participation in a rehabilitation program because mobility and ability to interact with others are hindered. Prevention is the best treatment. The clinical rule of protecting the patient's skin is to change position every 2 hours. No cushion can completely prevent decubitus ulcers.
URINARY TRACT INFECTIONS AND IMPAIRED BLADDER CONTROL
Urinary tract infections are a common source of sepsis and prolonged illness. An indwelling catheter is the most frequent source of contamination. In an acutely ill or multiply injured patient, an indwelling catheter may be necessary for medical reasons but should be removed as soon as possible. Urinary incontinence is not sufficient reason for continued use of an indwelling catheter. In male patients, incontinence can be managed with a carefully applied condom catheter. Care must be taken to inspect the penis frequently for signs of skin maceration or pressure. In female patients, diapering and frequent linen changes are necessary.
Restoring bladder function to achieve adequate reflex voiding or a balanced bladder may require the use of an intermittent catheterization program. In a balanced bladder, the volume of residual urine should not exceed a third of the volume of voided urine. In general, an intermittent catheterization program is initiated if the residual volume is greater than 100 mL or if the voided volume exceeds 400 mL. The patient is catheterized every 4 hours initially and then every 6 hours for 24 hours. Then the patient is reassessed. Good records are necessary throughout the program.
MUSCLE WEAKNESS AND PHYSIOLOGIC DECONDITIONING
During sustained exercise, the metabolism is mainly aerobic. The principal fuels for aerobic metabolism are carbohydrates and fats. In aerobic oxidation, the substrates are oxidized through a series of enzymatic reactions that lead to the production of adenosine triphosphate (ATP) for muscular contraction. A physical conditioning program can increase the aerobic capacity by improving cardiac output, increasing hemoglobin levels, enhancing the capacity of cells to extract oxygen from the blood, and increasing the muscle mass by hypertrophy.
Prolonged immobilization of extremities, bed rest, and inactivity lead to pronounced muscle wasting and physiologic deconditioning in a short period of time. Because disabled patients generally expend more energy than normal individuals in performing the routine ADLs, they must be mobilized as quickly as possible to prevent unnecessary physiologic decline. They should also be placed on a daily exercise program to maximize muscle strength and aerobic capacity.
Patients with spasticity exhibit an excessive response to the quick stretch of a muscle, which leads to hyperactive deep tendon reflexes and clonus. Spasticity must be managed aggressively to prevent permanent deformities and joint contractures.
Drugs can be of some assistance in controlling spasticity associated with upper motor neuron diseases. Drugs are used when spasticity affects multiple large muscle groups in the body and when the spasticity is not severe.
Baclofen (Lioresal) can inhibit both polysynaptic and monosynaptic reflexes at the spinal cord level. It does, however, depress general central nervous system function. Use of oral baclofen is avoided in traumatic brain-injured patients when possible because it may cause sedation and impede cognitive recovery. Patients with attention deficits or memory disorders may be compromised by antispastic agents, such as baclofen, diazepam, and clonidine, that have sedating properties. The drug tizanidine (Zanaflex) affects the central nervous system less than other agents and may be useful. Even a drug such as dantrolene sodium, which acts peripherally, may also cause drowsiness.
Baclofen pump technology has an advantage over oral drug therapy because of the small concentrations it introduces intrathecally. The small intrathecal doses control spasticity effectively while minimizing central side effects. The pump is placed in a subcutaneous pocket in the abdominal wall. A catheter is routed subcutaneously from the intrathecal space to the pump. The pump can be refilled by injection into the reservoir chamber. The dosage and rate of administration can be easily adjusted by using a laptop computer that sends radio signals to the pump.
Dantrolene (Dantrium), another drug that can be used to control spasticity, is the drug of choice for treating clonus. Dantrolene produces relaxation by directly affecting the contractile response of skeletal muscle at a site beyond the myoneural junction. It causes dissociation of the excitation–contraction coupling probably by interfering with the release of calcium from the sarcoplasmic reticulum. Although it does not affect the central nervous system directly, it does cause drowsiness, dizziness, and generalized weakness, which may interfere with the patient's overall function. Use of dantrolene for the control of spasticity is indicated in upper motor neuron diseases, such as SCI, cerebral palsy, stroke, or multiple sclerosis. The most serious problem encountered with the use of dantrolene is hepatotoxicity. The risk appears greatest in females, in patients older than 35 years, and in patients taking other medications. When using dantrolene, the lowest effective dose should be used, and liver enzyme functions should be monitored closely. If no effect is noted after 45 days of use, the drug should be stopped.
Casting temporarily reduces muscle tone and is frequently used to correct a contracture. The cast is changed weekly until the problem is corrected. If a cast must be used for a prolonged period, the patient should be placed on anticoagulant therapy to prevent deep venous thrombosis.
Anterior and posterior clamshell splints can be used to control joint position and still allow for active and passive range of motion (ROM) of the joints in therapy. A splint applied to only one side of an extremity is not sufficient to control excessive spasticity and may result in skin breakdown from motion of the extremity against the splint. A splint can also obscure an early contracture.
Anesthetic and phenol nerve blocks are often combined with a casting or splinting program.
Anesthetic nerve blocks are commonly used to eliminate muscle tone temporarily. They can be used diagnostically to evaluate what portion of a deformity is dynamic (occurring because of muscle spasticity) and what portion is secondary to myostatic contracture. The block can give an advanced indication of the likely results of surgical neurectomy or tendon lengthening. Repeated blocks of local anesthetics give a carryover effect to decrease muscle tone.
When muscle spasticity requires control for an extended period of time but the patient still has potential for spontaneous improvement, a phenol nerve block may be indicated. Phenol exerts two actions on the nerves. The first is a short-term effect, similar to the effect produced by a local anesthetic and directly proportional to the thickness of the nerve fibers. The second is a long-term effect that results from protein denaturation. Although this leads to wallerian degeneration of the axons, experimental studies in animals showed that the nerves regenerate with time. In patients, the direct injection of a nerve with a 3–5% solution of phenol after surgical exposure gives relief of spasticity for up to 6 months. Mixed nerves containing sensory fibers should not be injected because it could cause unwanted sensory loss or painful dysesthesia. Reduction of spasticity for up to 3 months can also be achieved by the percutaneous injection of muscle motor points with an aqueous solution of phenol after localization using a needle and nerve stimulator (Figure 13–2).
Ordinarily, an action potential propagating down to a motor nerve to the neuromuscular junction triggers the release of acetylcholine (ACh) into the synaptic space. The released ACh causes depolarization of muscle membrane. Botulinum toxin type A is a protein produced by Clostridium botulinum that attaches to the presynaptic nerve terminal and inhibits the release of ACh at the neuromuscular junction. Botulinum toxin is injected directly into a spastic muscle. Clinical benefit lasts 3–5 months. Current practice is not to administer a total of more than 400 U in a single treatment session to avoid excessive weakness or paralysis. This upper limit of 400 U may be reached rather quickly when injecting a few large muscles. A delay of 3–7 days between injection of botulinum toxin A and the onset of clinical effect is typical. The patient does not see effects immediately, and usually a follow-up visit is arranged to check the result. Because botulinum toxin is the most potent biologic toxin known, and the cost is relatively high, the smallest possible dose should be used to achieve results. Most studies report side effects in 20–30% of patients per treatment cycle. The incidence of adverse effects varies based on the dosage used (ie, the higher the dose, the more frequent the adverse effects); however, the incidence of complications is not related to the total dose of botulinum toxin used. Local pain at the injection site is the most commonly reported side effect. Other adverse effects (eg, local hematoma, generalized fatigue, lethargy, dizziness, flulike syndrome, pain in neighboring muscles) are also reported.
If muscle spasticity is permanent and no change in muscle tone is anticipated, definitive procedures such as dorsal rhizotomy, peripheral neurectomy, tendon lengthening or release, and tendon transfer should be considered.
Inactivity and uncontrolled spasticity often lead to joint contractures (Figure 13–3), which are difficult to correct and greatly extend the needed rehabilitation program. Contractures may cause difficulties in positioning an individual in a bed or chair or problems in using orthotic devices. They can also cause difficulties with hygiene and skin care and increase the risk of decubitus ulcers. Shoe wear may be rendered impossible secondary to foot deformities.
Muscle weakness is accentuated by contractures and malalignment, which cause the muscle to function at a mechanical disadvantage. Sitting and standing balance are compromised when contractural deformities displace the location of the center of gravity relative to the base of support. Functional use of the extremities is severely limited by lack of adequate joint motion. Joint contractures may require surgical release, which could further decrease function in an already compromised individual. Moreover, in children, joint contractures can lead to structural changes in the skeleton. Muscle growth lags behind skeletal growth, and this discrepancy in growth rates can cause increasing deformity with time.
To prevent contractures, exercises to maintain ROM must be performed several times daily. The patient, family members, therapists, and nursing personnel should all participate in this task.
Splinting can help maintain joints in a functional position when motor control is lacking. Splints should be removed regularly to inspect the skin condition and reassess their efficacy in maintaining the desired position.
Treatment of established contractures can be time consuming and expensive. In general, if a contracture is present for less than 3 months, it may be amenable to nonsurgical methods of correction such as serial casting or electrical stimulation of the antagonist muscles. Excessive muscle tone must be treated aggressively if present because it will only accentuate the tendency to form contractures. An anesthetic nerve block can be given to eliminate excessive tone temporarily and provide analgesia prior to manipulation of the joint and application of a cast. Each week, the cast is removed, a nerve block is given, and a new cast is applied. When the desired limb position is obtained, a holding cast is used to maintain the position for an additional week. The cast can then be bivalved and made into anterior and posterior clamshell splints, which can be removed for ROM or other activities. Another useful technique is the application of a dropout cast (Figure 13–4), which allows for further correction of the contracture while preventing the original deformity from recurring.
When contractural deformities are long standing and fixed, surgical release is indicated. Tendons, ligaments, and joint capsules are all involved. If the deformity is severe, complete correction at the time of surgery may be impossible. Neurovascular structures must be protected from excessive traction. Serial casts or dropout casts may be necessary following surgery to gain the desired limb position.
OTHER ACQUIRED MUSCULOSKELETAL DEFORMITIES
Paralysis or weakness of trunk muscles can lead to scoliotic deformities of the spine. These deformities can impair respiratory function and tend to cause balance problems when the patient walks and sits. External support in the form of bracing or seating modifications can eliminate or minimize this tendency.
Disuse and lack of muscle tone lead to osteoporosis, which in turn predisposes patients to fractures. The fractures should be treated aggressively and in a manner that maximizes function rather than prolonging immobilization.
Peripheral nerve palsy can result from pressure secondary to decreased mobility in patients confined to a bed or chair. Pressure can also result from braces, splints, and casts, and these require careful monitoring. In those patients who form heterotopic ossification, the new bone formation and the accompanying inflammation may impinge on peripheral nerves, thereby causing nerve palsy.
Evaluation of Impairment
Many disabilities requiring rehabilitation result from diseases affecting the nervous system. The location and the extent of the primary lesion determine not only the degree of paralysis but also the extent to which motor control is impaired and spasticity is present. In injuries or diseases of the peripheral nerves, the damage is confined to the lower motor neurons. Normal motor control is preserved, spasticity is absent, and the magnitude of disability depends on the extent of paralysis and weakness (paresis). In pathologic conditions of the brain or spinal cord, the upper motor neurons are affected, which not only causes muscular weakness but also impairs motor control.
Motor activity can be considered as a hierarchic system of voluntary and involuntary neurologic mechanisms.
Voluntary Muscle Activity
Two types of voluntary muscle activity are clinically identifiable: selective and patterned movements. The highest level of motor activity, selective movement, depends on the integrity of the cerebral cortex. Selective movement is the ability to flex or extend one joint preferentially without initiating a mass flexor or extensor motion at other joints of the limb. Patterned movement (synergy) at a joint refers to the ability to move one joint by invoking a mass flexion or extension synergy involving movement at other joints of the limb. Patients with central nervous system disorders may have voluntary patterned movement but lack selective movement. Because most patients have mixtures of selective and patterned movement at different joints, however, the strength of each type of activity must be assessed at each joint. Patterned flexion and extension movements of the lower limb can provide sufficient motor control for ambulation, but patterned motion does not provide sufficient fine control for upper extremity function.
Involuntary Muscle Activity
Spasticity relates to two types of involuntary muscle activity: clonic and tonic responses. Each type depends on the sensitivity of the muscle spindle to the rate of stretch. If a muscle is quickly extended above the threshold of the velocity-sensitive receptors of the spindle, a phasic response may be elicited. If spasticity is severe, sudden stretch may trigger clonus, which consists of repeated bursts of phasic activity at 6–8 cycles per second. The phasic stretch response has practical clinical significance. For example, if an ankle equinus deformity is present and spasticity is severe, clonus of the triceps surae may be triggered in the stance phase each time the patient takes a step. A rigid ankle-foot orthosis (AFO) that blocks ankle motion and prevents the triceps surae from stretching may inhibit clonus, enabling the foot to be held in a neutral position. An articulated or flexible AFO that allows the ankle to move and the triceps surae to stretch may not prevent clonus from being elicited and may be less effective.
If the muscle is stretched slowly below the threshold of the velocity components of the spindle, a phasic response is not triggered, but the spindle is still capable of detecting changes in length that may generate a tonic response consisting of continuous muscle hypertonus. The tonic muscle activity during slow stretch is called clasp-knife resistance. This tonic activity is also of practical significance. Even if the ankle is slowly dorsiflexed for a prolonged time, hypertonus may persist in the triceps surae and restrict normal motion. Consequently, it may be necessary to differentiate spasticity from myostatic contracture by performing peripheral nerve blocks.
Patients with injury involving the brainstem may exhibit severe hypertonus that is continuously present and is called either decorticate rigidity or decerebrate rigidity, depending on the posture of the limbs. In decerebrate posturing, the patient's arms are held tightly flexed while the legs are held in extension. In decorticate posturing, both the upper and lower extremities are in rigid extension. Patients with severe muscular rigidity are at extreme risk of developing contractural deformities.
When a spastic patient is sitting or standing, labyrinthine activation increases tone in the extensor muscles of the lower extremity and also increases upper limb flexion. Consequently, patients who are examined for spasticity should be evaluated in the upright rather than supine position, to elicit the maximal stretch response. Conversely, patients who are examined for maximal ROM should be evaluated in the supine position, to minimize muscle tone and enable maximal joint range. The limb posture of patients also influences the intensity of reflex and voluntary activity.
The final steps of sensory integration occur in the cerebral cortex, where basic sensory data are integrated into the more complex sensory phenomena. When central nervous system injury involves the cerebral cortex, the patient responds to basic modalities of touch and pain. Responses to tests of more complex aspects of sensation (such as shape, texture, and proprioception) and two-point discrimination may be impaired, however. These simple tests quickly determine the patient's ability to interpret basic sensory information. Patients with absent proprioception across the major lower joints have balance abnormalities or are unable to walk. Most patients do not routinely use an affected hand unless proprioception is intact. Patients without lesions of the cerebral cortex can generally discriminate between two points less than 10 mm apart applied simultaneously to the fingers.
Manual muscle testing is often useful for evaluating an individual's ability to perform functional tasks and also documents progress made in the rehabilitation program. Several systems are currently used, but all are based on the grading system introduced by Robert Lovett in 1932. The evaluation is subjective, but the use of gravity resistance provides a measure of objective standardization (Table 13–1). A normal muscle grade as determined by manual testing does not always imply normal strength. A significant amount of weakness (a 25–30% loss of strength) must be present to be detected by this method.
Normal gait is the combination of postures and muscle activities that produce forward motion with minimal energy expenditure (Figure 13–5).
The swing phase (Figures 13–5 and 13–6) is divided into three equal periods: initial swing, midswing, and terminal swing. During the three-part phase, the pelvis rotates from backward to forward and the hip flexes 20–30 degrees. The knee flexes to 60 degrees initially and then extends in preparation for contact with the ground. The knee flexion is largely responsible for the foot clearing the ground during swing. Knee flexion occurs as the result of the forward momentum of the limb swinging and not as a result of hamstring contraction. The ankle joint initially plantarflexes 10 degrees and then assumes a neutral position during terminal swing so that the heel normally contacts the floor first.
The hip flexor muscles provide the power for advancing the limb and are active during the initial two thirds of the swing phase. The ankle dorsiflexors become active during the latter two thirds of the phase to ensure foot clearance as the knee begins to extend. The hamstring muscles decelerate the forward motion of the thigh during the terminal period of the swing phase.
The stance phase (Figures 13–5 and 13–7) accounts for 60% of the gait cycle and can be divided into five distinct activities: initial contact, the loading response, midstance, terminal stance, and preswing. At initial ground contact, the ankle is in neutral position, the knee is extended, and the hip is flexed. The hip extensor muscles contract to stabilize the hip because the body's mass is behind the hip joint. During the loading response, the knee flexes to 15 degrees, and the ankle plantarflexes to absorb the downward force and conserve energy by minimizing the up-and-down movement of the body's center of gravity. As the knee flexes and the stance leg accepts the weight of the body, the quadriceps muscle becomes active to stabilize the knee. In midstance, the knee is extended, and the ankle is in a neutral position. As the body's mass moves forward of the ankle joint, the calf muscles become active to stabilize the ankle and allow the heel to rise from the floor. In terminal stance, the heel leaves the floor, and the knee begins to flex as momentum carries the body forward. In the final portion of terminal stance, as the body rolls forward over the forefoot, the toes dorsiflex at the metatarsophalangeal joints. During preswing, the knee is flexed to 35 degrees and the ankle plantarflexes to 20 degrees. Because the opposite extremity is also in contact with the floor, the preswing is called the time of double-limb support.
Throughout the stance phase, the hip gradually extends and the pelvis rotates backward. During the first portion of the stance phase, the ankle dorsiflexors and hamstring muscles remain active. During the loading response and early midstance, the gluteus and quadriceps muscles become active to provide hip and knee stability. In midstance, the gastrocnemius and soleus muscles become active to stabilize the ankle joint and control the forward advancement of the tibia. This allows the heel to rise from the floor and the body weight to roll forward over the forefoot.
The study of movement (kinesiology) provides many important tools for evaluating patients with gait abnormalities. Among the areas of study are stride analysis, motion analysis (kinematics), force analysis (kinetics), and muscle activity analysis.
Three of the many specialized tools used in these studies are dynamic electromyography, force plate studies, and motion analysis. Dynamic electromyography, which records the electrical activity in multiple muscles simultaneously during functional activities, elucidates the patterns of motor control in both the upper and the lower extremities and helps in the management of spasticity and gait abnormalities. Force plate studies, which measure ground reaction forces and the fluctuations of the center of pressure, can be used to analyze gait problems and quantify balance reactions in impaired patients. Motion analysis uses multiple cameras located at different positions around the room. The cameras detect sensors placed on the patient and create a three-dimensional model of the patient moving through space.
Muscle strength can be accurately measured using torque, which can be correlated with joint position. Joint stiffness can also be assessed by measuring torque while moving the joint through a passive arc of motion. Joint powers can be calculated by multiplying joint moment times angular velocity.
Measurement of velocity, stride length, cadence, and single- and double-limb support times can be combined with dynamic electromyography, force plate studies, and joint goniometric recordings to present a complete analysis of gait dysfunction. These studies can also be used to assess the influence of surgery, orthotic corrections, or prosthetic design on gait characteristics.
OXYGEN CONSUMPTION AND AEROBIC CAPACITY
Perhaps the most important measurement for understanding the difficulties faced by disabled people comes from oxygen consumption studies. Oxygen consumption indicates the energy required to perform an activity. Measuring an individual's maximal aerobic capacity is the single best indicator of the level of physical fitness.
Effects of Disease and Aging on Energy Expenditure
Cardiorespiratory disease, anemia, muscle atrophy, and any other condition that restricts oxygen uptake causes a decrease in the maximal aerobic capacity. Even in a healthy person, 3 weeks of bed rest decreases maximal aerobic capacity by up to 30%.
During normal walking, the rate of energy expenditure by adults varies from approximately 30% to 45% of the maximal aerobic capacity, with the higher percentage used in people over 60. Because of the decline in maximal aerobic capacity with age, an older person is more susceptible than a person under 50–60 years of age to the penalties of a gait disability.
Effects of Exercise on Energy Expenditure
When exercise is performed at less than 50% of an individual's maximal aerobic capacity, the exercise can be continued for prolonged periods because the ATP needed for muscle contraction is provided by aerobic pathways. Anaerobic pathways of ATP production, which do not use oxygen, increasingly come into play when exercise is performed at work rates exceeding approximately 50% of maximal aerobic capacity. The amount of energy that can be delivered by anaerobic metabolism is limited, and fatigue ensues because of the accumulation of lactate in the muscle. Consequently, the normal ADLs and working that must be performed throughout an 8-hour day, including walking, are performed below anaerobic threshold.
Effects of Musculoskeletal Impairment on Energy Expenditure
Gait abnormalities that interfere with efficient, coordinated limb movement can increase energy demand. Some affected patients respond to this increased demand by working harder, which increases the output of physiologic energy and is reflected in the higher-than-normal heart rate and oxygen consumption rate. Rather than increasing the rate of energy expenditure, however, most patients slow their gait velocity in an effort to keep the power requirement from exceeding normal limits.
Among amputees, patients progressively walk slower at increasingly more proximal amputation levels. Younger patients with traumatic or congenital amputations walk faster than older dysvascular amputees because of their greater maximal aerobic capacity. Patients with limited joint movement or with arthritis and painful joints also reduce their gait velocity. The heart rate and energy expenditure rate do not exceed normal in any of these groups of patients if crutches are not required.
Patients requiring crutches and exerting considerable force to support the body often have high heart rates and energy expenditure rates. A swing-through, crutch-assisted gait in a paraplegic or a patient who has a fracture and is unable to bear weight on one leg requires strenuous physical exertion, which is why few paraplegics use swing-through gait and why older patients with fractures can ambulate for only short distances. Even patients who use a reciprocal gait pattern, such as patients with low lumbar paraplegia resulting from SCI or myelodysplasia, use their arms for considerable exertion. Consequently, these types of patients may also be restricted ambulators in the community.
Patients with hip and knee flexion deformities caused by fixed or dynamic contractures require increasing muscle effort not only to walk but also to maintain an upright posture because the center of gravity during stance passes farther away from the axis of rotation of the joint. The fact that knee flexion greater than 30 degrees significantly increases the energy expenditure rate even in otherwise normal persons points to the importance of preventing and correcting contractures.
Children who have cerebral palsy and diplegia and who walk in a crouch gait may have energy expenditure rates that are above the anaerobic threshold. This is why these children are restricted ambulators who frequently discontinue walking when they mature and their maximal aerobic capacities decrease.
Use of Orthoses
Orthotic (brace) prescription plays a vital role in rehabilitation. The physician must understand the functional needs of the patient and provide the orthotist with an exact prescription that specifies the materials, type of joints, joint position, and ROM. Brace prescriptions should not be left to the discretion of the patient and orthotist.
A temporary orthosis may be used in an early stage of illness until a definitive, custom-fitted orthosis is fabricated. Definitive orthoses for the lower extremity are the below-knee ankle-foot orthosis (AFO) and the above-knee knee-ankle-foot orthosis (KAFO).
The bichannel adjustable ankle-locking (BiCAAL) type of AFO is commonly applied as the first orthosis following stroke, head trauma, spinal injury, or other condition that causes extensive muscle imbalance about the foot and ankle (Figure 13–8). A rigid ankle is useful in controlling plantarflexion spasticity, stabilizing the ankle in a flaccid limb, and correcting a dynamic varus deformity (inversion of the foot). The adjustable ankle joint mechanism enables the clinician to determine the optimal ankle position in the acute period following onset of illness when the neurologic picture and orthotic requirement are changing. Once neurologic recovery stabilizes, a plastic (polypropylene) orthosis often becomes the treatment of choice (Figure 13–9).
The use of plastic materials in lower extremity orthotics is now widespread. Orthoses fabricated from plastics are lighter, more comfortable, and more attractive. A plastic AFO can be rigid or can be flexible, allowing motion at the ankle. Polypropylene is presently the most practical plastic material. Skillful fitting is critical because of the close skin and bone contact.
Of several currently available orthoses classified as limited-motion ankle joint orthoses, two are commonly used: the conventional metal, double-upright, single-adjustable ankle joint with dorsiflexion spring assist (Klenzak) and the molded plastic posterior shells made from 116-inch polypropylene. The use of plastic materials makes the latter design preferable for most patients. When a greater restriction of ankle motion is desired, rigidity can be attained in several ways: by using a thicker sheet of polypropylene, by extending the lateral trim lines farther anteriorly at the ankle to serve as side struts, by adding an anterior shell to the posterior shell and totally enveloping the ankle, or by stiffening the posterior shell with the use of carbon fiber or lamination techniques. The trim lines may be reinforced with metal or additional layers of plastic. The foot plate of the orthosis extends just proximal to the metatarsal heads. Total circumferential orthoses combining anterior and posterior shells require exceptionally careful fitting to avoid excessive skin pressure over bony prominences. They are not recommended for routine use.
Insertion of a polypropylene orthosis inside a shoe generally requires a shoe size that is a half size larger and wider than that previously worn by the patient. To eliminate the need to purchase two pairs of shoes of different sizes, an inlay can be inserted in the shoe of the sound limb to prevent excessive looseness once a shoe is fitted on the polypropylene side. The ankle position of the polypropylene orthosis should be assessed with the patient wearing his or her shoe with the normal heel height.
The primary requirement for orthotic support is that all joints must be passively capable of being positioned in adequate alignment. An orthosis cannot correct a fixed bony deformity or fixed joint contracture.
INADEQUATE DORSIFLEXION FOR FOOT CLEARANCE DURING SWING
An AFO is indicated for inadequate toe clearance (footdrop) during the midswing phase of gait. This problem may result from inadequate ankle dorsiflexion caused by weakness of the dorsiflexors or by the inability of dorsiflexors to overcome spasticity of the triceps surae. A lightweight, flexible polypropylene orthosis is indicated if inadequate dorsiflexion is the only problem at the ankle. A flexible orthosis can also be used for a mild swing-phase varus deformity (foot inversion). A rigid orthosis is needed in patients who have excessive plantarflexion resulting from severe spasticity and in patients who initiate a strong extensor pattern activity prior to heel strike.
INADEQUATE DORSIFLEXION FOR INITIAL CONTACT
A patient with inadequate dorsiflexion from any cause contacts the ground with the forefoot or with the foot flat and the tibia extended backward. This problem is commonly combined with varus deformity, and weight bearing is on the lateral edge of the foot. The results are a backward thrust to the limb, which decreases forward momentum and produces excessive hyperextension forces on the knee, which leads to knee instability in the patient who is a functional walker. A rigid AFO in the neutral position provides heel strike for the patient who has full-knee extension and allows the tibia to rotate forward during stance.
MEDIAL-LATERAL SUBTALAR INSTABILITY DURING STANCE
Varus deformity is more common than valgus deformity. The patient walks on the lateral border of the foot and is hesitant to accept weight on the leg. A rigid orthosis can correct the varus deformity unless spasticity is severe. To correct a mild varus deformity, a limited ankle orthosis may be used. No orthosis is effective in controlling the severe spastic varus deformity.
INADEQUATE TIBIAL STABILITY DURING STANCE
Some patients have inadequate strength or control of the plantarflexors for maintenance of normal tibial position and alignment during stance. Early after midstance, this problem is manifested by excessive dorsiflexion and accompanying knee flexion. Whether or not the limb collapses during weight bearing depends on the amount of quadriceps muscle control and strength. Patients with sufficient proprioception learn to compensate by locking the knee in hyperextension as the foot contacts the floor, which keeps the knee from buckling. A rigid orthosis that prevents both dorsiflexion and plantarflexion is indicated to provide vertical tibial alignment during midstance. Its use prevents tibial collapse forward during terminal stance as a substitution for adequate calf control.
A knee extension thrust, caused by inadequate calf control as described earlier, may result also from severe plantarflexion tone or fixed equinus deformity resulting from contracture. At foot strike, the forefoot strikes the floor first, resulting in a knee extension or hyperextension thrust. A rigid AFO with a plantarflexion block prevents the development of knee instability and pain.
A T-strap (a leather T-shaped strap attached to the brace at the ankle and applied around the ankle to hold the foot from either an inverted or everted position) is usually not desirable for correction of severe varus deformity in patients fitted with metal orthoses. If a T-strap is applied with sufficient force to provide significant control to prevent foot twisting, it usually causes excessive pressure over the lateral malleolus in the patient with severe spasticity. This problem can be treated better by the use of a split anterior tibial tendon transfer or by the addition of a lateral wedge and flare to the shoe of the nonsurgical candidate.
A KAFO may be used if quadriceps muscle weakness or hamstring muscle spasticity is present. A knee immobilizer may be used as a training aid before having a KAFO fabricated. A KAFO is more difficult to don than a below-knee brace, and most patients with a central nervous system disease such as stroke or cerebral palsy have difficulty walking with a KAFO. Consequently, if hamstring spasticity rather than quadriceps spasticity necessitates external support to align the knee in extension, it is preferable to perform hamstring tenotomy or tendon lengthening, thereby eliminating the need for knee support.
Most patients with lower extremity quadriceps paresis resulting from SCI lack sufficient proprioception to walk with a free-knee mechanism (unlocked knee joint mechanism).
When a KAFO is prescribed for quadriceps paresis, it is necessary to determine if the knee will be locked while walking or if it will be freely movable to allow knee flexion in swing. When a KAFO is prescribed because of knee instability or because of varus or valgus instability, a polycentric joint (a joint in which the center of rotation moves following the anatomic instantaneous center of rotation) permits flexion extension movement but blocks medial and lateral angulation. A posterior stop added to the knee mechanism prevents excessive hyperextension.
If proprioception is intact, as is the case with poliomyelitis, even patients with considerable quadriceps weakness may be able to walk with an unlocked knee using an offset knee joint. This is accomplished by careful orthotic alignment. The center of rotation of the orthosis is positioned anterior to the center of rotation of the knee. As long as the patient can fully extend the knee in the swing stage preparatory to limb loading, the resulting movement caused by vertical loading acts to extend the knee against the posterior stop, thereby locking the knee in extension. This requires at least fair (grade 3) hip flexor strength (see Table 13–1) to provide sufficient forward momentum of the leg to position the knee in full extension.
The substitution of plastic components, such as a pretibial shell, has led to significantly improved fit and reduced weight in KAFOs.
SPINAL CORD INJURY
Trauma to the spinal cord causes dysfunction of the cord, with nonprogressive loss of sensory and motor function distal to the point of injury. Approximately 400,000 people have spinal cord damage in the United States, and the incidence rate is estimated to be 10,000 per year. The leading causes of SCI are motor vehicle accidents, gunshot wounds, falls, sports (especially diving) injuries, and water injuries.
Patients are generally categorized into three groups. The first consists predominantly of younger individuals who sustained their injury from a motor vehicle collision or other high-energy traumatic accident. The second consists of individuals over 50 years of age with cervical spinal stenosis caused by congenital narrowing or spondylosis. Patients in this second group often sustained their injury from minor trauma and commonly have no vertebral fracture. The third group consists of people with gunshot wounds, which are now the leading cause of spinal injury in many urban centers in the United States. With the benefits of an organized program of medical care, the life expectancy of survivors of SCI is now approaching the normal level.
The term tetraplegia (preferred to quadriplegia) refers to loss or impairment of motor or sensory function (or both) in the cervical segments of the spinal cord with resulting impairment of function in the arms, trunk, legs, and pelvic organs.
Paraplegia refers to loss or impairment of motor or sensory function (or both) in the thoracic, lumbar, or sacral segments of the spinal cord. Arm function is intact but, depending on the level of the cord injured, impairment in the trunk, legs, and pelvic organs may be present.
The term complete injury refers to an injury with no spared motor or sensory function in the lowest sacral segments.
Incomplete injury refers to an injury with partial preservation of sensory or motor function (or both) below the neurologic level and includes the lowest sacral segments.
Neurologic Impairment & Recovery
The neurologic examination is critical to the classification and treatment of spinal injuries because it determines the patient's potential level of recovery. The neurologic level of the lesion refers to the highest neural segment having normal motor and sensory function. Patients are further subdivided according to whether they have complete or incomplete spinal cord function. This is determined by the absence or presence of motor or sensory function in the most distal part of the spinal cord innervating the sacral nerves. The presence of sacral nerve function is critical because patients with incomplete injuries have the potential to recover normal neurologic function over a time span of up to 2 years even if paralysis is initially complete.
The diagnosis of complete SCI cannot be made until the period of spinal shock is over, as evidenced by the return of the bulbocavernosus reflex. To elicit this reflex, the clinician examines the patient's rectum digitally, feeling for contraction of the anal sphincter while squeezing the glans penis or clitoris. The concept of spinal shock is important and can be understood on the basis of the monosynaptic stretch reflex. At a given neural segment of the spinal cord, afferent sensory fibers enter the spinal cord and anastomose with the anterior motor neurons at the same level. If trauma to the spinal cord causes complete injury, reflex activity at the site of injury will not return because the reflex arc is permanently interrupted. When spinal shock disappears, however, reflex activity does return in the distal segments below the level of injury. In a patient with complete SCI, spinal shock may last for as little as several hours or as long as several months. Patients with complete SCI who have recovered from spinal shock have a negligible chance for any useful motor return.
The presence or absence of sacral function determines the completeness of the injury. Sacral motor function is assessed by testing contraction of the external anal sphincter (graded as present or absent). Sacral sensation is tested at the anal mucocutaneous junction. Additionally, testing of the external anal sphincter is performed by assessing perceived deep sensation as present or absent when the examiner's finger is inserted.
SPINAL CORD SYNDROMES
Anterior Cord Syndrome
Anterior cord syndrome commonly results from direct contusion to the anterior cord by bone fragments or from damage to the anterior spinal artery. Depending on the extent of cord involvement, only posterior column function (proprioception and light touch) may be present. The ability to respond to pain (tested by discriminating sharp and dull) and to light touch (tested with a wisp of cotton) signifies that the entire posterior half of the cord has some intact function and thus offers a better prognosis for motor recovery. If there is no recovery of motor function and pain sensation 4 weeks after injury, the prognosis for significant motor return is poor.
Central Cord Syndrome
Central cord syndrome can be understood on the basis of the spinal cord anatomy. The gray matter in the spinal cord contains nerve cell bodies and is surrounded by white matter consisting primarily of ascending and descending myelinated tracts. The central gray matter has a higher metabolic requirement and is therefore more susceptible to the effects of trauma and ischemia. Central cord syndrome often results from a minor injury such as a fall in an older patient with cervical spinal canal stenosis. The overall prognosis for patients with central cord syndrome is variable. Most patients are able to walk despite severe paralysis of the upper extremity.
Brown-Séquard syndrome is caused by a complete hemisection of the spinal cord, resulting in a greater ipsilateral proprioceptive motor loss and a greater contralateral loss of pain and temperature sensation. Affected patients have an excellent prognosis and can usually ambulate.
Mixed syndrome is characterized by a diffuse involvement of the entire spinal cord. Affected patients have a good prognosis for recovery. As with all incomplete SCI syndromes, early motor recovery is the best prognostic indicator.
Most patients with spinal cord injuries have associated injuries. In this setting, assessment and treatment of airway, respiration, and circulation takes precedence. The patient is best treated initially in the supine position.
Airway management in the setting of SCI, with or without a cervical spine injury, is complex and difficult. The cervical spine must be maintained in neutral alignment at all times. Clearing of oral secretions and/or debris is essential to maintain airway patency and to prevent aspiration. Failure to intubate emergently when indicated because of concerns regarding the instability of the patient's cervical spine is a potential pitfall.
Hypotension may be hemorrhagic and/or neurogenic in acute SCI. Because of the vital sign confusion in acute SCI and the high incidence of associated injuries, a diligent search for occult sources of hemorrhage must be made. The most common causes of occult hemorrhage are chest, intraabdominal, or retroperitoneal injuries and pelvic or long bone fractures. Appropriate investigations, including radiography or CT scanning, are required.
Once occult sources of hemorrhage are excluded, initial treatment of neurogenic shock focuses on fluid resuscitation. Judicious fluid replacement with isotonic crystalloid solution to a maximum of 2 liters is the initial treatment of choice.
Associated head injury occurs in approximately 25% of SCI patients. A careful neurologic assessment for associated head injury is compulsory. The presence of amnesia, external signs of head injury or basilar skull fracture, focal neurologic deficits, associated alcohol intoxication or drug abuse, and a history of loss of consciousness mandates a thorough evaluation for intracranial injury, starting with noncontrast head CT scanning.
Ileus is common. Placement of a nasogastric tube is essential. Aspiration pneumonitis is a serious complication in the SCI patient with compromised respiratory function. Antiemetics should be used aggressively.
The National Acute Spinal Cord Injury Studies (NASCIS) II and III, a Cochrane review of all randomized clinical trials and other published reports, verified significant improvement in motor function and sensation in patients with complete or incomplete spinal cord injuries who were treated with high doses of methylprednisolone within 8 hours of injury. The current recommendation is to treat all SCI patients within 3 hours of injury with the following steroid protocol: methylprednisolone 30 mg/kg bolus over 15 minutes and an infusion of methylprednisolone at 5.4 mg/kg/hour for 23 hours beginning 45 minutes after the bolus.
The NASCIS III study evaluated methylprednisolone 5.4 mg/kg/hour for 24 or 48 hours versus tirilazad 2.5 mg/kg every 6 hours for 48 hours. (Tirilazad is a potent lipid preoxidation inhibitor. High doses of steroids or tirilazad are thought to minimize the secondary effects of acute SCI.) All patients received a 30 mg/kg bolus of methylprednisolone intravenously. The study found that in patients treated earlier than 3 hours after injury, the administration of methylprednisolone for 24 hours was best. In patients treated 3–8 hours after injury, the use of methylprednisolone for 48 hours was best. Tirilazad was equivalent to methylprednisolone for 24 hours.
The use of high-dose methylprednisolone in nonpenetrating acute SCI is the standard of care in North America. However, the validity of these results came into question on the basis of statistical analysis, randomization, and clinical endpoints. The risks of steroid therapy are not inconsequential. An increased incidence of infection and avascular necrosis is documented. Nevertheless, most physicians practice the administration of high-dose steroids within 3 hours of injury for all acute SCI patients.
Two studies addressed the administration of GM-1 ganglioside following acute SCI. The available medical evidence does not support a significant clinical benefit. It is recommended as a treatment option after the administration of methylprednisolone.
Prevention of contractures and maintenance of ROM are important in all patients with SCI and should begin immediately following the injury. Teaching the patient to sleep in the prone position is the most effective means of preventing hip and knee flexion contractures. Passive stretching of the hamstring muscles with the knee extended is initiated to prevent shortening of these muscles secondary to spasticity. For patients to be able to dress the lower parts of their body independently, they must be able to flex the lumbar spine and hip 120 degrees with the knee extended.
Patients with extensive paralysis of the lower extremity need strength in both arms to manipulate crutches and bring the body to a standing position. Patients who lack at least fair (grade 3) strength in their quadriceps muscles (see Table 13–1) require KAFOs to stabilize the knee and also require the knee to be locked in extension while walking. Patients who have bilateral KAFOs commonly use a swing-through, crutch-assisted gait rather than a reciprocal gait. Because strenuous upper extremity exertion is required and the rate of energy expenditure is extremely high when crutches are used, nearly all patients prefer to use a wheelchair. In contrast, patients who have fair (grade 3) or greater strength in their hip flexors and knee extensors are able to walk with unlocked (free) knees and only require AFOs to stabilize their feet and ankles. These patients also usually require crutches because of absent or impaired hip extensor and adductor muscles, but they are able to achieve a reciprocal gait pattern and can walk for a limited duration outside the home. Most of them prefer a wheelchair when they must ambulate over long distances.
Because most ambulatory patients with SCI have impaired hip extensor support, they learn to hyperextend the lumbar spine so the center of gravity of the trunk is posterior to the hip joint in the stance phase of gait. This prevents forward collapse and decreases the demand on the arms during crutch use. Spine stabilization procedures that decrease the flexibility of the lower lumbar spine or reduce the amount of lordosis deprive the patient of an important gait maneuver.
UPPER BODY AND EXTREMITIES
C4 Level Function
Patients with cervical lesions above C4 may have impairment of respiratory function, depending on the extent of injury, and may require a tracheostomy and mechanical ventilatory assistance.
Phrenic nerve stimulation via implanted surgical electrodes enables patients to use their own diaphragm and ventilate without mechanical assistance if the cause of their diaphragm paralysis is upper motor neuron injury. With training, these patients should be able to achieve a vital capacity that is 50–60% of normal using only the diaphragm.
Patients with high tetraplegia can use chin or tongue controls to operate an electric wheelchair with attached respiratory equipment. Mouth sticks that are lightweight rods attached to a dental bite plate enable patients to perform desktop skills, operate push-button equipment, and pursue vocational and recreational activities.
C5 Level Function
At the C5 level, the key muscles are the deltoid and biceps muscles, which are used for shoulder abduction and elbow flexion. If these muscles are weak, the patient benefits from mobile arm supports attached to a wheelchair that are balanced to exert a vertical force to counteract gravity. This enables the patient with poor muscle strength to feed independently and perform other functional tasks with the hands. A ratchet wrist-hand orthosis (WHO) with a fixed wrist joint and a passively closing mechanism attached to the thumb and fingers enables the patient to grasp objects between the thumb and fingers.
Surgery can further enhance upper extremity function. The goals of surgery are to provide active elbow and wrist extension and to restore the ability to pinch the thumb against the index finger (key pinch or lateral pinch). Transferring the posterior deltoid to the triceps muscle provides active elbow extension. Transferring the brachioradialis to the extensor carpi radialis brevis provides active wrist extension. Attaching the flexor pollicis longus tendon to the distal radius and fusing the interphalangeal joint of the thumb provides for key pinch by tenodesis when the wrist is extended.
C6 Level Function
At the C6 level, the key muscles are the wrist extensors, which enable the patient to propel a wheelchair manually, transfer from one position to another, and even live independently.
If wrist extensor strength is poor, an orthosis is indicated. A WHO with a free wrist joint and a rubber-band extensor-assist mechanism enables the patient to complete wrist extension. A wrist-driven WHO with a flexor hinge mechanism that causes the metacarpophalangeal joint to flex when the wrist is extended enables the patient to grasp actively between the fingers and thumb. Some patients develop a natural tenodesis of their thumb and finger flexor muscles because of myostatic contracture or spasticity, and this tenodesis enables them to grasp without an orthosis.
Most patients with good wrist extensor strength are able to operate a manual wheelchair but may require an electric wheelchair for long distances. These patients may also be able to transfer independently if they have no elbow flexion contractures and they can lock their elbows passively in extension while transferring.
The goals of surgery in the C6 patient are the restoration of lateral pinch and active grasp. Lateral pinch can be restored either by tenodesis of the thumb flexor or by transfer of the brachioradialis to the flexor pollicis longus. Active grasp can be restored by transfer of the pronator teres to the flexor digitorum profundus.
C7 Level Function
At the C7 level, the key muscle is the triceps. All patients with intact triceps function should be able to transfer and live independently if no other complications are present. Despite their ability to extend the fingers, these patients may also require a WHO with a flexor hinge mechanism.
The goals of surgery in the C7 tetraplegic patient are active thumb flexion for pinch, active finger flexion for grasp, and hand opening by extensor tenodesis. Transfer of the brachioradialis to the flexor pollicis longus provides active pinch. Transfer of the pronator teres to the flexor digitorum profundus allows for active finger flexion and grasp. If the finger extensors are weak, tenodesis of these tendons to the radius provides hand opening with wrist flexion.
C8 Level Function
At the C8 level, the key muscles are the finger and thumb flexors, which enable a gross grasp. The functioning flexor pollicis longus enables patients to obtain lateral pinch between the thumb and the side of the index finger. Intrinsic muscle function is lacking, and clawing of the fingers is usually present. A capsulodesis of the metacarpophalangeal joints corrects the clawing and improves hand function. Active intrinsic function can be gained by splitting the superficial finger flexor tendon of the ring finger into four slips and transferring these tendons to the lumbrical insertions of each finger.
Maintaining skin integrity is crucial to spinal injury care. From the moment the patient enters the emergency room, preventive measures are instituted to avoid skin breakdown even while critical diagnostic procedures and lifesaving measures are performed. Only 4 hours of continuous pressure on the sacrum is sufficient to cause full-thickness skin necrosis. Turning the patient from side to back to side every 2 hours avoids skin ulceration, a problem that greatly prolongs the cost and length of rehabilitation. Following the simple procedures outlined here usually obviates the need for flotation devices, Stryker frames, cyclically rotating beds, and similar equipment.
Once the patient is allowed to sit, a progressive program to increase the time of sitting tolerance is undertaken. Paraplegics with normal upper extremity function are taught to perform raises automatically in the wheelchair and decompress the skin for approximately 15 seconds every 15 minutes. Tetraplegics who are unable to perform raises can lean to either side or lean forward for 1-minute intervals every hour to achieve decompression. Those patients unable to perform decompressive maneuvers require assistance from another person or may use an electric wheelchair with a powered recliner that enables them to assume a supine posture every hour.
All patients must be taught to inspect their skin at least twice a day, when dressing and undressing. Mirrors attached to a rod enable paraplegics to examine their skin over the sacrum and ischia independently. Tetraplegics usually require assistance with skin inspection.
If there is evidence of chronic skin inflammation over bony prominences or if redness persists 30 minutes after removal of pressure, action must be taken to avoid incipient pressure necrosis. Pressure transducers placed under the bony prominences determine if pressure exceeds acceptable levels. Up to 40 mm Hg is well tolerated by most patients. If pressures exceed this amount, a custom-fitted foam cushion with appropriate cutouts is prescribed.
Development of any open areas in the skin over the ischia or sacrum, even superficial areas, is an indication to discontinue sitting temporarily. The patient must remain in a prone or side-lying position to avoid pressure until the lesion is healed. Failure to take aggressive steps to eliminate pressure and allow healing leads to chronic inflammation, scarring, and a loss of elasticity, creating a vicious cycle that further increases susceptibility to pressure necrosis.
Excessive hip and knee flexor spasticity that prevents patients from assuming the prone position or lying supine and requires them constantly to assume a side-lying posture when in bed can lead to excessive pressure over the greater trochanters. Flexor spasticity or contracture that prevents continuous turning should be corrected medically prior to development of pressure sores and must be performed before skin flap placement. Failure to correct flexion deformities inevitably decreases the likelihood of successful skin closure. Surgical tenotomy and myotomy of hip and knee flexors is the most effective surgical method for correcting the problem when nonoperative measures fail. Neurosurgical procedures such as myelotomy or rhizotomy are usually less effective and run the risk of interfering with reflex bladder emptying and penile erections.
In the neglected patient with a full-thickness pressure sore, surgery is necessary. The initial phase consists of debridement of all infected soft tissue and bone as well as treatment of spasticity and contractures that may have predisposed the patient to pressure sores. Once all wounds have a clean granulating base and the patient is able to remain prone 24 hours a day, he or she becomes a candidate for a rotational flap. The gluteus maximus, the tensor fasciae latae, and other types of musculocutaneous flaps give the surgeon a superior and reliable method of providing skin coverage. Sitting tolerance must be carefully reestablished following flap surgery. Because most pressure sores in patients with chronic SCI are the result of failure to relieve pressure by appropriate measures, patient education is the key element of a successful rehabilitation outcome.
Ischial or trochanteric pressure sores commonly lead to septic arthritis of the hip. In such cases, femoral head and neck resection is required. In the paraplegic with an intact hip joint, the passive weight of the limbs cantilevered about the posterior thigh exerts an upward force on the pelvis, which decompresses the ischia. Consequently, approximately 30% of the body weight is supported on the thigh. Femoral head and neck resection disrupts the bony leg of the femur to the pelvis and results in a greater concentration of pressure on the ischia, thereby increasing the chance of recurrence even after successful flap closure.
Pressure sores affecting the ankle commonly occur over the heel or malleolus. After initial debridement, wound healing can nearly always be obtained by placing the patient in a short leg cast that protects the wound from any external pressure. The cast is changed every 1 or 2 weeks until healing occurs. Rotational flaps are rarely needed.
Intermittent catheterization is the factor most responsible for the nearly normal life span of patients with spinal cord injuries. In this group, urinary tract infection is no longer the leading cause of death. Most patients who have intact sacral reflex activity following complete injury are able to obtain reflex bladder emptying. Some patients with complete SCI are able to trigger reflex bladder emptying by tapping the suprapubic area, stroking the thighs, or using the Credé method (applying external pressure on the bladder to induce emptying) or the Valsalva maneuver (forcibly exhaling against the closed glottis). These patients require an external condom catheter for men or diapering for women. Patients with nonreflex bladders void by the application of pressure on the bladder by the Valsalva maneuver or Credé method. Not all so-called reflex bladders empty reflexively, and some, despite reflex emptying, have an excessive amount of residual urine. Anticholinergic medications to decrease bladder neck spasm of the smooth muscle of the internal sphincter or spasmolytic medications to decrease tone in the striated muscle of the external sphincter may improve bladder emptying. Some patients require surgical sphincterotomy.
Bladder diversion using an ileal conduit as a primary means of achieving bladder drainage is contraindicated. This procedure leads to a chronic acid–base imbalance, osteoporosis, and, ultimately, renal failure from secondary infection. The suprapubic catheter also is to be avoided as a means of primary treatment for the same reasons that permanent indwelling catheters are contraindicated. The constant presence of an indwelling catheter leads to bladder constriction and increases the risks of renal calculi, infection, and death from renal failure. For male patients, the external condom catheter is the treatment of choice. For female patients, padding or diapering is the preferred treatment, although some women prefer an indwelling catheter despite the risks of a shortened life span.
Women with or without intact reflex activity can perform coitus and deliver normal children. Approximately 90% of men with complete SCI and sacral reflex activity can be expected to have reflex erections. Most of these men are able to perform coitus; however, fewer than half can ejaculate. Sacral sparing plays a great role in prognosticating sexual potential in the male patient. Those able to distinguish pain (discrimination of sharp and dull) are usually able to achieve psychogenic erections.
Splanchnic outflow conveying sympathetic fibers to the lower body exits at the T8 region. Patients with lesions above T8 are prone to autonomic dysreflexia. They are subject to bouts of hypertension that may be heralded by dizziness, sweating, and headaches. A plugged catheter is the most common precipitating cause of dysreflexia. The catheter should be carefully checked and the bladder irrigated. Other frequent causes of dysreflexia include calculi or infections in any portion of the urinary system, fecal impaction, and pressure sores. If the patient's blood pressure does not lower in response to treatment of the causative agent, management with antihypertensive medication is begun.
The International Standards for Neurological and Functional Classification of Spinal Cord Injury, published by the American Spinal Injury Association (ASIA) and the International Medical Society of Paraplegia (IMSOP), represent the most reliable instrument for assessing neurologic status in SCI. These standards provide a quantitative measure of sensory and motor function.
Neurologic recovery is assessed by determining the change in ASIA Motor Score (AMS) between successive neurologic examinations. The AMS is the sum of strength grades for each of the 10 key muscles tested bilaterally that represent neurologic segments from C5 to T1 and L2 to S1. In a neurologically intact individual, the total possible AMS is 100 points.
The most important prognostic indicator of recovery is completeness of injury using the sacral-sparing definition. Using completeness and level of injury (tetraplegia or paraplegia), patients are divided into four groups: complete tetraplegia, incomplete tetraplegia, complete paraplegia, and incomplete paraplegia. The rate of motor recovery in all groups declines rapidly in the first 6 months following injury with minimal further changes after this time (Figure 13–10).
Patients with paraplegia that remains complete 1 month after injury have a 96% chance of remaining complete. Thirty-eight percent of those with injuries at or below T9 recover some lower extremity function. No patients with a neurologic level above T9 regain volitional lower extremity motor function. Only 5% of muscles with a strength of 0/5 at 1 month recover to 3/5 or greater strength 1 year after injury. Furthermore, only 5% of individuals become independent community ambulators at 1 year.
Motor recovery is better in individuals with incomplete injuries. Between 1 month and 1 year after injury, the AMS increases by an average of 12 points regardless of the level of injury. Additionally, these patients have a 76% chance of becoming community ambulators.
Ninety percent of individuals with complete tetraplegia 1 month after injury remain complete. Among the 10% who undergo late conversion to incomplete status, lower extremity motor recovery is minimal and inadequate for ambulation. Recovery of AMS points is independent of neurologic level. Waters and colleagues reported that with the exception of the triceps muscle, all upper extremity muscles with grade of at least 1/5 1 month after injury recover to at least 3/5 1 year following injury.
In patients with incomplete tetraplegia, motor recovery of upper and lower extremity muscles occurs concurrently. Nearly all muscles with at least 1/5 strength 1 month after injury recover to at least 3/5 1 year postinjury. Forty-six percent of the patients examined by Waters and colleagues attained independent community ambulation status 1 year after injury. The number of individuals with incomplete tetraplegia who can attain independent community ambulation is less than for individuals with incomplete paraplegia and comparable lower extremity function. This is because upper extremity function may be insufficient to allow crutch-assisted ambulation in the former group, whereas those with incomplete paraplegia have normal upper extremity strength.
Taken as a whole, a minority of individuals with SCI can ambulate independently after injury. The proportion of patients who can ambulate does, however, vary with the level and completeness of the injury. The lower extremity motor score (LEMS), which is the sum of the strength grades of the bilateral key lower extremity muscles, can be used to predict successful ambulation (Table 13–2). The motor groups are as follows: L2, hip flexors (iliopsoas); L3, knee extensors (quadriceps); L4, ankle dorsiflexors (tibialis anterior); L5, long toe extensors (extensor hallucis longus); and S1, ankle plantarflexors (gastrocnemius, soleus). In an individual with no deficit, the total possible LEMS is 50 points. The LEMS at 30 days is used to predict the chance of successful ambulation in incomplete tetraplegics, incomplete paraplegics, and complete paraplegics. All individuals with a LEMS of at least 20 and an incomplete injury are expected to be community ambulators 1 year after injury.
Stroke (cerebrovascular accident or brain attack) occurs when thrombosis, embolism, or hemorrhage interrupts cerebral oxygenation and causes the death of neurons in the brain. This leads to deficits in cognition and in motor and sensory function.
In the United States, where cerebrovascular accidents are the leading cause of hemiplegia in adults and the third leading cause of death, 2 million people have permanent neurologic deficits from stroke. The annual incidence of stroke is 1 in 1000, with cerebral thrombosis causing nearly three fourths of the cases. More than half of stroke victims survive and have an average life expectancy of approximately 6 years. Most survivors have the potential for significant function and useful lives if they receive the benefits of rehabilitation.
Neurologic Impairment & Recovery
Infarction of the cerebral cortex in the region of the brain supplied by the middle cerebral artery (MCA) or one of its branches is most commonly responsible for stroke. Although the middle cerebral artery supplies the area of the cerebral cortex responsible for hand function, the anterior cerebral artery supplies the area responsible for lower extremity motion (Figure 13–11). The typical clinical picture following middle cerebral artery stroke is contralateral hemianesthesia (decreased sensation), homonymous hemianopia (visual field deficit), and spastic hemiplegia with more paralysis in the upper extremity than in the lower extremity. Because hand function requires relatively precise motor control, even for activities with assistive equipment, the prognosis for the functional use of the hand and arm is considerably worse than for the leg. Return of even gross motor control in the lower extremity may be sufficient for walking.
Infarction in the region of the anterior cerebral artery causes paralysis and sensory loss of the opposite lower limb and to a lesser degree the arm. Patients who have cerebral arteriosclerosis and suffer repeated bilateral infarctions are likely to have severe cognitive impairment that limits their general ability to function even when motor function is good.
After stroke, motor recovery follows a fairly typical pattern. The size of the lesion and the amount of collateral circulation determine the amount of permanent damage. Most recovery occurs within 6 months, although functional improvement may continue as the patient receives further sensorimotor reeducation and learns to cope with disability.
Initially after a stroke, the limbs are completely flaccid. Over the next few weeks, muscle tone and spasticity gradually increase in the adductor muscles of the shoulder and in the flexor muscles of the elbow, wrist, and fingers. Spasticity also develops in the lower extremity muscles. Most commonly, there is an extensor pattern of spasticity in the leg, characterized by hip adduction, knee extension, and equinovarus deformities of the foot and ankle (Figure 13–12). In some cases, however, a flexion pattern of spasticity occurs, characterized by hip and knee flexion.
Whether the patient recovers the ability to move one joint independently of the others (selective movement) depends on the extent of the cerebral cortical damage. Dependence on the more neurologically primitive patterned movement (synergy) decreases as selective control improves. The extent to which motor impairment restricts function varies in the upper and lower extremities. Patterned movement is not functional in the upper extremity, but it may be useful in the lower extremity, where the patient uses the flexion synergy to advance the limb forward and the mass extension synergy for limb stability during standing.
The final processes in sensory perception occur in the cerebral cortex, where basic sensory information is integrated to complex sensory phenomena such as vision, proprioception, and perception of spatial relationships, shape, and texture. Patients with severe parietal dysfunction and sensory loss may lack sufficient perception of space and awareness of the involved segment of their body to ambulate. Patients with severe perceptual loss may lack balance to sit, stand, or walk. A visual field deficit further interferes with limb use and may cause patients to be unaware of their own limbs.
Medical intervention in the treatment of a stroke is most effective when initiated within 3 hours from the onset of symptoms. However, pharmacologic intervention may play a role, although limited, if administered within 24 hours of onset.
TISSUE PLASMINOGEN ACTIVATOR (T-PA) (ALSO KNOWN AS RECOMBINANT T-PA OR RECOMBINANT TISSUE-TYPE PLASMINOGEN ACTIVATOR [RT-PA])
The efficacy of intravenous t-PA was established in two randomized double-blind placebo-controlled studies published in combination by the National Institute of Neurological Disorders and Stroke (NINDS). At 3 months after stroke, approximately 12% more patients in the t-PA group experienced a cure of symptoms relative to those who did not receive it. The risk of intracerebral hemorrhage in the t-PA group was 6% (50% of which were fatal), compared to 0.6% in the placebo group. Despite the differences in hemorrhage rates, there were no differences in mortality (17% in the t-PA group versus 21% in the placebo group).
Key points about the administration of thrombolytic agents include the following:
PROUROKINASE (ALSO KNOWN AS RECOMBINANT PROUROKINASE, OR R-PRO-UK)
This intraarterial therapy requires the involvement of a skilled interventionist. The time window is 6 hours from symptom onset. In addition, and in contrast to the NINDS t-PA study, patients with a CT scan showing over a third involvement of the MCA territory as seen on CT scan are not eligible for treatment. The absolute percentage increase in patients with slight or no disability at 3 months was 15% in the prourokinase group compared with the placebo group. The hemorrhage rate in the prourokinase group was 10% versus 2% in subjects who received placebo. No difference was noted, however, in mortality (25% in the prourokinase group versus 27% in the placebo group).
This therapy may be especially useful for patients who arrive later than 3 hours from symptom onset and who have less than a third involvement of the MCA territory on initial scan.
The Chinese Acute Stroke Trial (CAST) and the International Stroke Trial (IST) are two large studies evaluating the use of aspirin (160–300 mg/d) within 48 hours of ischemic stroke symptom onset. Compared to no treatment, there was approximately a 1% absolute reduction in stroke and death in the first few weeks. At further time points (eg, 6 months), there was a similar absolute reduction of approximately 1% in death or dependence.
An ongoing phase III study of the efficacy of abciximab (ReoPro) in acute stroke is being conducted. A phase II study of 400 patients found an 8% absolute reduction in poor outcomes at 3 months (P < 0.05). Symptomatic intracranial hemorrhage occurred in 3.6% of patients on abciximab and in 1.0% of patients on placebo.
No studies have evaluated use of warfarin for the acute treatment of stroke.
HEPARIN AND HEPARINOIDS
At this time, only one randomized trial showed benefit for heparins or heparinoids in acute ischemic stroke. In that study, no benefit was seen at 10 days or 3 months, only at 6 months. Other large studies failed to find benefit of heparin or heparinoids, either intravenous or subcutaneous, at 3 months. An exploratory post hoc analysis of one intravenous low molecular randomized study suggested benefit in patients with severe large vessel (eg, carotid) atherosclerosis; however, the authors conclude that these findings need to be properly evaluated in a prospective randomized trial.
Various classes of neuroprotectants were tested and include calcium channel antagonists, potassium channel openers, glutamate antagonists, antiadhesion molecules, N-methyl-D-aspartate (NMDA) receptor antagonists and modulators, -amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor antagonists, membrane stabilizers, growth factors, and glycine site antagonists. At this time, no neuroprotectant shows efficacy in the treatment of acute stroke.
To walk independently, the hemiplegic patient requires intact balance reactions, hip flexion to advance the limb, and stability of the limb for standing. If a patient meets these criteria and has acceptable cognition, the orthopedic surgeon can restore ambulation in most cases by prescribing an appropriate lower extremity orthosis and an upper extremity assistive device such as a cane. Surgery to rebalance the muscle forces in the leg can greatly enhance ambulation.
Except for the correction of severe contractures in nonambulatory patients, surgical procedures should be delayed for at least 6 months to allow spontaneous neurologic recovery to occur and the patient to learn how to cope with the disability. After this time, surgery may safely be performed to improve usage in the functional limb.
In the nonfunctional limb, surgery may be performed to relieve pain or correct severe hip and knee flexion contractures caused by spasticity. Most severe contractural deformities in the nonfunctional limb, however, are the result of an ineffective program of daily passive ROM, splinting, and limb positioning.
Most hemiplegics with motor impairment have hip abductor and extensor weakness. A quad cane (cane with four feet to provide more stability) or a hemiwalker is prescribed to provide better balance. Because of paralysis in the upper extremity, the hemiplegic patient is unable to use a conventional walker.
Scissoring of the legs caused by overactive hip adductor muscles is a common problem. This gives the patient an extremely narrow base of support while standing and causes balance problems. When no fixed contracture of the hip adductor muscles is present, transection of the anterior branches of the obturator nerve denervates the adductors and allows the patient to stand with a broader base of support. If a contracture of the adductors occurs, surgical release of the adductor longus, adductor brevis, and gracilis muscles should be performed (Figure 13–13).
Patients with a stiff-knee gait are unable to flex the knee during the swing phase of gait. The deformity is a dynamic one meaning that it only occurs during walking. Passive knee motion is not restricted, and the patient does not have difficulty sitting. Usually the knee is maintained in extension throughout the gait cycle. Toe drag, which is likely in the early swing phase, may cause the patient to trip. Thus, balance and stability are also affected. The limb appears to be functionally longer. Circumduction of the involved limb, hiking of the pelvis, or contralateral limb vaulting may occur as compensatory maneuvers.
A gait study with dynamic electromyography (EMG) should be done preoperatively to document the activity of the individual muscles of the quadriceps. Dyssynergic activity is commonly seen in the rectus femoris from preswing through terminal swing throughout the gait cycle. Abnormal activity is also common in the vastus intermedius, vastus medialis, and vastus lateralis muscles. If knee flexion is improved with a block of the femoral nerve or with botulinum toxin injection of the quadriceps, the rationale for surgical intervention is strengthened. Any equinus deformity of the foot should be corrected prior to evaluation of a stiff-knee gait because equinus causes a knee extension force during stance. Because the amount of knee flexion during swing is directly related to the speed of walking, the patient should be able to ambulate with a reasonable velocity to benefit from surgery. Hip flexion strength is also needed for a good result because the forward momentum of the leg normally provides the inertial force to flex the knee. In the past a selective release of the rectus femoris or rectus and vastus intermedius was done to remove their inhibition of knee flexion. On average, a 15-degree improvement in peak knee flexion was seen after surgery. Transfer of the rectus femoris to a hamstring tendon not only removes it as a deforming muscle force; it also converts the rectus into a corrective flexion force. This procedure provides improved knee flexion over selective release. When any of the vasti muscles are involved, they can be selectively lengthened at their myotendinous junction (Figure 13–14) and knee flexion improves.
Knee Flexion Deformity
A knee flexion deformity increases the physical demand on the quadriceps muscle, which must continually fire to hold the patient upright. Knee flexion often leads to knee instability and causes falls. It is most often caused by spasticity of the hamstring muscles. A KAFO can be used to hold the knee in extension on a temporary basis as a training aid in physical therapy. Such an orthosis, however, is difficult for the stroke patient to don and wear for permanent usage.
Surgical correction of the knee flexion deformity is the most desirable treatment. Hamstring tenotomy (Figure 13–15) eliminates the dynamic component of the deformity and generally results in a 50% correction of the contracture at the time of surgery. The residual joint contracture is then corrected by serial casting done weekly after surgery. Hamstring function posterior to the knee joint is not necessary for ambulation. In fact, ambulation may only be feasible in patients with knee flexion deformities of greater than 30 degrees if a hamstring release is done.
Equinus or Equinovarus Foot Deformity
Surgical correction of an equinus deformity is indicated when the foot cannot be maintained in the neutral position with the heel in firm contact with the sole of the shoe in a well-fitted, rigid AFO. Despite a wide variety of surgical methods designed to decrease the triceps surae spasticity, none is more effective than Achilles tendon lengthening. In this procedure, triple hemisection tenotomy is performed via three stab incisions, with the most distal cut based medially to alleviate varus pull of the soleus muscle (Figure 13–16).
An anesthetic block of the posterior tibial nerve can be a valuable tool in preoperative assessment of the patient with equinus deformity because it demonstrates the potential benefits of Achilles tendon lengthening if the deformity is a result of increased muscle tone.
Surgical release of the flexor digitorum longus and brevis tendons at the base of each toe (Figure 13–17) is done prophylactically at the time of Achilles tendon lengthening because increased ankle dorsiflexion following heel cord tenotomy increases tension on the long toe flexor and commonly leads to excessive toe flexion (toe curling). The flexor hallucis longus and flexor digitorum longus tendons can be transferred to the os calcis to provide additional support to the weakened calf muscles.
Surgical correction of varus deformity is indicated when the problem is not corrected by a well-fitted orthosis. It is also indicated to enable the patient to walk without an orthosis when varus deformity is the only significant problem. The tibialis anterior, tibialis posterior, extensor hallucis longus, flexor hallucis longus, flexor digitorum, and soleus pass medial to the axis of the subtalar joint and are potentially responsible for varus deformity. EMG studies demonstrate that the peroneus longus and peroneus brevis are generally inactive, and the tibialis posterior is also usually inactive or minimally active.
The tibialis anterior is the key muscle responsible for varus deformity, and in most patients, this can be confirmed by visual examination or palpation while the patient walks. A procedure known as the split anterior tibial tendon transfer (Figure 13–18) diverts the inverting deforming force of the tibialis anterior to a corrective force. In this procedure, half of the tendon is transferred laterally to the os cuboideum. When the extensor hallucis longus muscle is overactive, it can be transferred to the middorsum of the foot as well.
Treatment of equinovarus deformity consists of simultaneously performing the Achilles tendon lengthening procedure and the split anterior tibial tendon transfer. At surgery, the tibialis anterior is secured and held sufficiently taut to maintain the foot in a neutral position. After healing, 70% of patients are able to walk without an orthosis.
The first objective in treating the spastic upper extremity is to prevent contracture. Severe deformities at the shoulder, elbow, and wrist are seen in the neglected or noncompliant patient. Assistive equipment can be used to position the upper extremity, to aid in prevention of contractures, and to support the shoulder. Positioning extends spastic muscles but does not subject them to sudden postural changes that trigger the stretch reflex and aggravate spasticity. Brief periods should be scheduled when the upper extremity is not suspended and time can be devoted to ROM therapy and hygiene.
Most hemiplegics do not use their hand unless some selective motion is present at the fingers or thumb. Thumb opposition begins with opposition of the thumb to the side of the index finger (lateral or key pinch) and proceeds by circumduction to oppose each fingertip. In most stroke patients with selective thumb–finger extension, proximal muscle function is comparatively intact. Hence, orthotic stabilization of proximal joints is rarely necessary in the patient with a functional hand.
An overhead suspension sling attached to the wheelchair is used for patients with adductor or internal rotator spasticity of the shoulder. An alternative is an arm trough attached to the wheelchair.
It is usually not possible to maintain the wrist in neutral position with a WHO when wrist flexion spasticity is severe or when the wrist is flaccid. With minimal to moderate spasticity, either a volar or dorsal splint can be used. The splint should not extend to the fingers if the finger flexor spasticity is severe because slight motion and sensory contact of the fingers or palm may elicit the stretch reflex or grasp response, causing the fingers to jack-knife out of the splint.
Shoulder or Arm Pain
The hemiplegic shoulder deserves special attention because it is a common source of pain. A variety of different factors contribute to the painful shoulder: reflex sympathetic dystrophy, inferior subluxation, spasticity with internal rotation contracture, adhesive capsulitis, and degenerative changes about the shoulder. If early ROM exercises are performed and the extremity is properly positioned with a sling to reduce subluxation, severe or chronic pain at the shoulder can usually be prevented or minimized.
The classic clinical signs of reflex sympathetic dystrophy (swelling and skin changes) may not be apparent in the hemiplegic patient. If the patient complains that the arm is painful and no cause is apparent, a technetium bone scan assists in establishing the diagnosis (Figure 13–19). Treatment should be instituted immediately, and the patient should be given positive psychological reinforcement. The use of narcotics must be avoided. Treatment options include the use of medications such as corticosteroids, amitriptyline, or gabapentin (Neurontin), physical therapy, or nerve blocks (stellate ganglion blocks, brachial plexus blocks, or Bier IV regional blocks). Each of these techniques is successful with some patients; however, none is reliable for all patients.
Contracture of the shoulder can cause pain, hygiene problems in the axilla, and difficulty in dressing and positioning. Shoulder adduction and internal rotation are caused by spasticity and myostatic contracture of four muscles: the pectoralis major, the subscapularis, the latissimus dorsi, and the teres major.
When the deformity is not fixed, lengthening of the pectoralis major, latissimus, and teres major at their myotendinous junction provides satisfactory correction of the deformity. In a nonfunctional extremity, surgical release of all four muscles (Figure 13–20) is usually necessary to resolve the deformity. Release of the subscapularis muscle is performed without violating the glenohumeral joint capsule. The joint capsule should not be opened because instability or intraarticular adhesions may result. A Z-plasty of the axilla may be needed if the skin is contracted. After the wound heals, an aggressive mobilization program is instituted. Gentle ROM exercises are employed to correct any remaining contracture. Careful positioning of the limb in abduction and external rotation is necessary for several months to prevent recurrence.
Elbow Flexion Contracture
Persistent spasticity of the elbow flexors causes a myostatic contracture and flexion deformity of the elbow. Frequent accompanying problems include skin maceration, breakdown of the antecubital space, and compression neuropathy of the ulnar nerve.
Surgical release of the contracted muscles and gradual extension of the elbow corrects the deformity and decreases the ulnar nerve compression. The brachioradialis muscle and biceps tendon are transected. The brachialis muscle is fractionally lengthened at its myotendinous junction by transecting the tendinous fibers on the anterior surface of the muscle while leaving the underlying muscle intact (Figure 13–21). Complete release of the brachialis muscle is not performed unless a severe contracture was present for several years. An anterior capsulectomy is not needed and should be avoided because of the associated increased stiffness and intraarticular adhesions that occur postoperatively. Anterior transposition of the ulnar nerve may be necessary to further improve ulnar nerve function.
Approximately 50% correction of the deformity can be expected at surgery without causing excessive tension on the contracted neurovascular structures. Serial casts or dropout casts can be used to obtain further correction over the ensuing weeks.
A spastic clenched-fist deformity in a nonfunctional hand causes palmar skin breakdown and hygiene problems. Recurrent infections of the fingernail beds are also common.
Adequate flexor tendon lengthening to correct the deformity cannot be attained by fractional or myotendinous lengthening without causing discontinuity at the musculotendinous junction. Transection of the flexor tendons is not recommended because any remaining extensor muscle tone may result in an unopposed hyperextension deformity of the wrist and digits. The recommended procedure is a superficialis-to-profundus tendon transfer (Figure 13–22), which provides sufficient flexor tendon lengthening with preservation of a passive tether to prevent a hyperextension deformity. The wrist deformity is corrected by release of the wrist flexors. A wrist arthrodesis is done to maintain the hand in a neutral position and to eliminate the need for a permanent splint. Because intrinsic muscle spasticity is always present in conjunction with severe spasticity of the extrinsic flexors, a neurectomy of the motor branches of the ulnar nerve in the Guyon canal should be routinely performed along with the superficialis-to-profundus tendon transfer to prevent the postsurgical development of an intrinsic plus deformity.
After surgery, the wrist and digits are immobilized for 4 weeks in a short arm cast extended to the fingertips.
A major challenge facing society is the aging of the population. By 2020, 52 million Americans will be older than 65 years. By 2040, 68 million people will be older than 65 years. Both the absolute numbers and proportion of elderly people is increasing dramatically. People are living longer and have higher expectations for a good quality of life. Despite this trend, proportionally less disability occurs among the elderly now than in the past.
Although the passage of time, chronological age, is the convenient measure used, it is not necessarily the most precise marker of aging. A more sensitive marker would be to consider the person's functional age, but this is often difficult to define and measure. Age 65 is generally considered the beginning of old age.
The young elderly are those individuals 65 to 75 years of age. These people are usually functionally intact. They have isolated orthopedic problems, such as mild osteoporosis, osteoarthrosis, overuse injuries (sports), and occasionally cancer.
The frail very elderly are those persons older than 80 years. These people tend to have multiple musculoskeletal impairments such as advanced osteoporosis, generalized muscle weakness, multiple organ diseases, and dementia.
The leading causes of death in the elderly are heart disease, malignant neoplasms, and cerebrovascular disease. The overall leading causes of disability in the elderly are cancer, heart disease, dementia, and musculoskeletal disorders. The leading causes of disease-related disability before death are arthritis, hypertension, hearing impairment, heart disease, and orthopedic conditions. Despite the increasing incidence of disability with aging, only 5% of Americans live in nursing homes.
When evaluating the elderly, five functional domains of disability need to be considered:
Disability in basic ADLs is common among community-dwelling older persons, with prevalence rates ranging from 7% in those 65 to 74 years of age to 24% in those 85 years of age or older. Restricted activity, defined as staying in bed for at least half a day and/or cutting down on usual activities because of an illness, injury, or other problem, is common among community-living older persons, regardless of risk for disability, and it is usually attributable to several concurrent health-related problems. Although disability in older persons is often thought to be progressive or permanent, previous research shows it is a dynamic process, with individuals moving in and out of states of disability. To set realistic goals and plan for appropriate care, disabled older persons, along with their families and clinicians, need accurate information about the likelihood and time course of recovery. Prevention of functional decline and disability includes not only management of acute episodes of disability and promotion of recovery, but also ongoing evaluation and management of key risk factors for disability and use of preventive interventions. The high likelihood of recurrent disability among older persons suggests that those who recently recovered from an episode of disability are an important target population for preventive interventions. Although some interventions designed to prevent recurrent disability may be disease specific (eg, anticoagulation after embolic stroke), others may be broadly applicable regardless of the specific precipitant of disability (eg, exercise-based programs).
Challenges for the Orthopedic Surgeon
When working with the elderly, the orthopedic surgeon becomes a member of a multidisciplinary team. The people making up this team include internists, geriatricians, rehabilitation specialists, psychiatrists, psychologists, social workers, nutritionists, skin care specialists, physical and occupational therapists, and the so-called young elderly children of the patient. Osteoporosis, fractures, arthritis, foot disorders, stroke, and amputations are the most frequent causes of musculoskeletal impairment.
Osteoporosis is an age-related disorder characterized by decreased bone mass and increased fracture risk in the absence of other recognizable causes of bone loss. Osteoporosis can occur either as a primary disorder or secondary to other diseases.
Primary osteoporosis, the most common form of the disease, occurs in people from 51 to 65 years of age with a female-to-male ratio of 6:1. Primary osteoporosis can be further subdivided into two types. Type I, postmenopausal osteoporosis, results from decreased circulating levels of estrogen. It is seen in postmenopausal women and affects the majority of persons older than 70 years. Bone loss is rapid. There is swift trabecular bone loss up to 8% per year. Type I osteoporosis causes primarily trabecular bone loss with only 0.5% cortical bone loss per year. Fractures occur in locations of trabecular bone loss such as the distal radius and vertebrae. The cause of primary osteoporosis is a changing hormonal milieu.
Type II, senile osteoporosis, is a consequence of aging. It causes a more global bone loss affecting cortical and cancellous bone such as in the femoral neck. Type II osteoporosis is seen in persons older than 70 years. The female-to-male ratio is 2:1. The bone loss occurs in both the trabecular and cortical bone and averages 0.3–0.5% per year. Fractures occurring as the result of type II osteoporosis typically involve the hip, pelvis, humerus, tibia, and vertebral bodies. The causes of senile osteoporosis are those seen with aging and include calcium deficiency, decreased vitamin D, and increased parathormone activity.
Secondary osteoporosis results from a variety of causes. The most common are chronic or prolonged corticosteroid use and endocrine disorders. The endocrine disorders associated with osteoporosis are hyperthyroidism; hyperparathyroidism; diabetes, Cushing disease, and euplastic disorders.
Restoration of bone is difficult. It is therefore imperative to maximize peak bone mass during skeletal growth and then to maintain it during maturity. This requires adequate dietary calcium and vitamin D intake. The recommended amounts for adults are 1200 mg/day of calcium and 400 mg of vitamin D. For postmenopausal women, 1500 mg/day of calcium is recommended. Impact exercise is effective in maintaining bone mass. It is also important to avoid those factors that promote osteoporosis such as the use of tobacco products and excessive alcohol consumption.
Osteoporosis is a clinical diagnosis often made following a fracture. Radiographic findings include osteopenia (seen with more than 30% mineral loss); loss of horizontal trabeculae in vertebral bodies; thoracic wedge fractures; lumbar spine endplate fractures; stress fractures of the pelvis; and fractures of humerus, wrist, hip, supracondylar femur, tibial plateau. Quantification of bone mass is done for confirmation and follow-up. Dual-energy x-ray absorptiometry (DEXA) is used to quantify bone mass. The following criteria for diagnosis are based on the DEXA scan:
Normal: within 1 standard deviation (SD) of young adult reference
Osteopenia: between 1.0 and 2.4 SD below reference
Osteoporosis: 2.5 or more SD below reference
Severe osteoporosis: 2.5 plus one or more fragility fractures
Calcium alone does not prevent bone loss during the early postmenopausal period, but adequate daily calcium replacement is helpful. In late menopause (more than 6 years), calcium replacement does reduce bone loss. Weight-bearing exercise is also useful in maintaining bone mass.
Newer treatments using bisphosphonates show promise in treating osteoporosis. The bisphosphonates are a class of compounds similar to pyrophosphate that are readily adsorbed by bone mineral surfaces. Once bound, they inhibit the bone absorption activity of osteoclasts. Two bisphosphonates currently are available for clinical use: alendronate sodium (Fosamax) and risedronate sodium (Actonel).
Only approximately a third of women in the United States diagnosed with osteoporosis during the 1990s were offered treatment for the condition. Fewer than 2% of the women 60 years and older were diagnosed with osteoporosis, but the rate increased from 1.2% in 1993 to 2.7% in 1997. Overall, 36% of women diagnosed with osteoporosis were prescribed calcium, vitamin D, or drugs to treat the disease, but this also increased, from 20% in 1993 to 55% in 1997.
The ability to walk safely is vital for independent living. Both strength and endurance determine the capacity for independent movement. Muscle strength is associated with the capacity to perform ADLs. A reduction in strength with age is attributed to these factors:
Strength training can lead to major functional improvements in the elderly. The plasticity of the motor system to adapt to a training load appears to be maintained into the 10th decade of life. Strength training has no effect on the central determinants of aerobic capacity such as maximum heart rate, blood pressure hemoglobin concentration, and blood volume.
Aerobic exercise does lead to increased endurance and functional capacity. Endurance is the time a person can maintain either a static force or a power level involving a combination of concentric or eccentric muscular contractions. The stress that exercise imposes on a person and the tolerance or endurance for that exercise intensity depends on how much energy is needed to perform the task in relation to the person's maximal capacity. With training, activities become easier to perform. The person has increased endurance for submaximal exercise. Improvements in movement can lower the energy cost of an activity.
Osteoarthritis is very prevalent in the elderly. Total joint arthroplasty has dramatically improved the mobility and quality of life for the elderly. A variety of studies confirm the appropriateness and effectiveness of both total hip and total knee arthroplasty in the elderly with low complication rates. The elderly patient is more likely to require the use of an upper extremity assistive device for ambulation following joint replacement.
One of the most compelling reasons to determine the etiology of a fracture and provide appropriate treatment is that a previous low-energy fracture is among the strongest risk factors for new fractures. Specifically, patients with a low-energy fracture of the wrist, hip, proximal humerus, or ankle have nearly a two- to fourfold greater risk for future fractures than individuals who have never experienced a fracture. Furthermore, up to half of patients with a prior vertebral fracture experience additional vertebral fractures within 3 years, many within the first year. Indeed, compared to individuals with no history of fracture, a patient with a prior vertebral fracture has nearly a fivefold increased risk of future vertebral fractures and up to a sixfold increased risk of hip and other nonvertebral fractures. Taken together, these data indicate that patients with a history of any type of prior fracture have a two- to sixfold increased risk of subsequent fractures compared to those without a previous fracture.
These findings emphasize that optimal care of fragility fracture patients includes not only management of the presenting fracture, but also evaluation, diagnosis, and treatment of the underlying cause(s) of the fracture, including low bone density or other medical conditions. In this regard, supplementation with calcium and vitamin D lowers fracture risk in the elderly. In addition, several pharmacologic agents reduce the risk of future fracture by as much as 50% in patients with existing fractures. Nonpharmacologic interventions, such as fall prevention programs and individually tailored exercise programs, reduce falls among the elderly, which may decrease the incidence of fractures. In addition, trochanteric padding dramatically reduces hip fractures among those at highest risk. Thus, initiating interventions soon after a fragility fracture occurs may significantly reduce the incidence and severity of subsequent fractures.
In the elderly, fractures result from low-energy injuries. Falls in the home most frequently result in fractures of the hip, distal radius, pelvis, proximal humerus, and ribs. Approximately 90% of fractures of the pelvis, hip, and forearm result from a fall. Only 3–5% of falls result in fractures.
Many of the risk factors for fracture are also risk factors for falls. Risk factors can be divided into categories. Risk factors associated with aspects of aging include primary osteoporosis, impaired vision or balance; gait abnormalities; and loss of muscle and fat padding the bones. Environmental risk factors consist of uneven surfaces; slippery surfaces; obstacles such as throw rugs, pets, and steps; poor lighting; and lack of railings or other supports for balance. Fall prevention programs include home safety measures such as the installation of safety bars in the bathtub and shower, elimination of heavily waxed floors and slippery rugs, and the use of rubber sole shoes with low wide heels that provide more stability.
Genetic factors are seen in both gender and race. Women sustain more fractures than men. Whites have more fractures than African Americans. Illnesses commonly associated with fractures include stroke, syncope, hypotension, secondary osteoporosis, Parkinson disease, dementia, and paraparesis. The use of medications such as benzodiazepines, tricyclic antidepressants, antipsychotics, corticosteroids, and barbiturates are connected with fractures. Lifestyle factors include exercise, nutrition, alcohol or other substance abuse, immobilization, and shoe style.
Other factors contribute to the risk of traumatic fractures occurring in falls. The first is the orientation of the fall. A fall that happens while standing still or walking very slowly imparts little or no forward momentum so the point of impact is near the hip. Gait velocity slows with aging, putting the hip more at risk of injury in a fall. Protective responses during a fall decrease with age. Local shock absorbers, muscle and fat, that surround the bone decrease with age. Bone strength is less secondary to the osteoporosis associated with aging.
Fractures of the hip are classified by location and severity. The basic considerations are whether the fracture occurs in the intracapsular or extracapsular area and the stability of the fracture pattern. Intracapsular fractures occur along the neck of the femur. When they are displaced, the blood supply to the femoral head is likely disrupted, which increases the possibility of osteonecrosis.
Treatment of hip fractures is operative whenever possible. The nonoperative treatment of hip fractures is very occasionally chosen for patients at high medical risk. It is sometimes recommended for demented nonambulatory patients. The nonoperative treatment of a hip fracture involves months of bed rest and sometimes traction. It requires excellent nursing care to avoid decubitus ulcers and respiratory dysfunction. Fracture malunion, limb-length inequality, pain, and higher mortality rates are common with nonoperative care. The chances for eventual ambulation are only 55% compared with 76% for patients treated operatively.
The basic principles of treatment of hip fractures are well established. Nondisplaced fractures of the femoral neck are usually treated with multiple pins or screws. Displaced fractures of the femoral neck are usually treated with a hemiarthroplasty because of the high incidence of avascular necrosis. Stable intertrochanteric fractures are generally treated with a sliding screw and side plate system. Unstable intertrochanteric fractures may require additional measures to gain adequate medial support. In very osteoporotic bone, it may be necessary to add methyl methacrylate bone cement to gain sufficient fixation and stability. When a patient is known to have severe arthritis, a primary total hip arthroplasty may be performed.
The postoperative rehabilitation of the elderly patient is critical to a successful outcome. Non–weight-bearing ambulation is extremely difficult and more often impossible for elderly patients. Every effort should be made in the operative treatment to gain enough stability of the fracture to allow weight bearing as tolerated. The patient should be mobilized on the first or second day after surgery to prevent the many complications of immobility. Pain management is important to allow mobilization, but oversedation of the elderly patient needs to be avoided. When a prosthesis was inserted, dislocation must be avoided. The elderly patient may not remember the precautions. Use of elevated chairs and toilet seats helps avoid the excessive hip flexion associated with posterior dislocation. A knee immobilizer splint while in bed prevents knee flexion that in turn results in flexion of the hip. It is prudent occasionally to place the patient in a hip brace, which limits flexion and adduction while soft-tissue healing occurs.
FRACTURES OF THE PELVIS
A common pelvic classification is based on whether or not the ring of the pelvis is disrupted because this indicates the amount of energy involved with the initial trauma. A fracture that does not disrupt the pelvic ring such as a pubic ramus fracture is a low-energy injury. Formerly, pelvic fractures were associated with high-energy trauma, were displaced, and occurred in patients less than 40 years old. With the aging of America, now more than 50% of fractures occur in those older than 60 years, with a preponderance occurring in women. The majority of pelvis fractures in the elderly are low-energy injuries and can be treated nonoperatively with analgesia and bed rest. Early mobilization is desirable to prevent the complications of immobility. Full weight bearing is allowed. A walker or other assistive device is useful to decrease pain and increase stability during walking. Stool softeners are often helpful. Fractures of the coccyx and sacrum are treated in a similar manner.
FRACTURES OF THE DISTAL FEMUR
The management of distal femur fractures in the elderly patients must be individualized. Advanced age in itself is not a contraindication to surgery. The objects of surgical treatment of the distal femur are anatomic reduction and stable fixation. In the presence of severe osteopenia, stable fixation is difficult. The addition of methyl methacrylate or long-stem knee replacement can help with stability. Occasionally, a postoperative cast brace is needed to supplement the internal fixation.
FRACTURES OF THE FOREARM
Most fractures of the distal radius (Colles fracture) can be treated by closed reduction and casting. Significant loss of radial height and dorsal comminution can occur in osteoporotic bone even after lower energy injuries. In this situation, most surgeons would agree that external fixation and bone grafting of the fracture are warranted to obtain and maintain a more anatomic reduction. Early ROM exercises for both the shoulder and the fingers should be encouraged to avoid stiffness.
FRACTURES OF THE PROXIMAL HUMERUS
Fractures of the proximal humerus account for 4–5% of all fractures and occur most commonly in the elderly. Humeral fractures in the elderly are minimally displaced 80% of the time. In these cases, sling immobilization is used to control pain. Pendulum exercises are begun early to prevent excessive stiffness in the shoulder. Limited external rotation of the shoulder predisposes to a future spiral fracture of the humerus during dressing. In unstable and markedly displaced fractures of the humeral head, a hemiarthroplasty can be considered. If coexisting severe osteoarthritis of the glenohumeral joint is present, a total shoulder arthroplasty can be considered.
Stroke is a common cause of disability in the elderly. This topic was covered in detail earlier in this chapter.
The foot tends to widen with age as the transverse arch support weakens and abnormal bony alignments of the foot become common. Surgical reconstruction of foot deformities may be contraindicated in the frail elderly patient, particularly because of peripheral vascular disease. Nonoperative treatment consists of active and passive ROM exercises of the foot to maximize flexibility. Strengthening exercises of the lower extremity can be useful to improve the overall gait pattern. The patient should try to optimize body weight to eliminate excessive forces on the foot. Functional orthoses of a semirigid material with little or no posting may improve the foot position and provide symptomatic relief. Accommodative orthoses of a soft material may also be used. These soft orthoses are designed to control foot posture and eliminate areas of pressure, but they are not intended to correct the foot position. Orthoses are used in combination with soft extra-depth shoes that provide more clearance for deformities of the toes. Flat shoes are helpful for forefoot deformities because they prevent the foot sliding forward in the shoe. A shoe with a low heel is desirable for patients with a severe pronation deformity because the Achilles tendon is commonly tight. Placing the heel cord on stretch only increases the pronation forces on the foot.
The majority of amputations done in a civilian population are of the lower extremity. Most amputations are done in the sixth decade of life or later, so this is largely a problem of the elderly. The issues associated with amputation are discussed in Chapter 12.
Brain injury resulting from trauma to the head is a leading cause of death and disability. Head injury is at least twice as common in males as in females and occurs most often in people 15–24 years of age. Approximately half of the injuries result from motor vehicle accidents. In the United States, 410,000 new cases of traumatic brain injury can be expected each year, with each case presenting a challenge to the team of health care providers involved in providing emergency treatment and long-term management.
Neurologic Impairment & Recovery
The Glasgow Coma Score (Table 13–3) is frequently used to evaluate eye opening, motor response, and verbal response of patients with impaired consciousness. Analysis of scores from patients in several countries sheds light on the chances for survival and neurologic recovery. According to the data, approximately 50% of patients with impaired consciousness survived. Six months after injury, moderate or good neurologic recovery was seen in 82% of patients with initial (24-hour) Glasgow scores of 11 or higher, 68% of patients with initial scores of 8–10, 34% with initial scores of 5–7, and 7% with initial scores of 3 or 4. Age was an important factor related to neurologic outcome, with 62% of patients younger than 20 years and 46% of patients between 20 and 29 years of age showing moderate or good recovery.
The incidence of good recovery declines not only with advancing age but also with advancing duration of coma. Patients recovering from coma within the first 2 weeks of injury have a 70% chance of good recovery. The recovery rate drops to 39% in the third week and to 17% in the fourth week. Decerebrate or decorticate posturing indicates a brainstem injury and is indicative of a poor prognosis.
The rehabilitation process has three distinct phases: the acute injury period, the subacute period of neurologic recovery, and the residual period of functional adaptation. Health care workers from a variety of disciplines are involved in each phase.
PHASES OF PATIENT CARE AND REHABILITATION
Acute Injury Phase
The initial phase of rehabilitation begins as soon as the patient reaches the acute-care hospital. Brain injury is frequently the result of a high-velocity accident. Diagnosis is problematic because multiple injuries are common, resuscitation and other lifesaving efforts make a complete examination difficult, and the patient who is comatose or disoriented cannot assist in the history or physical examination.
Under the circumstances, three important principles should be followed. The first is to make an accurate diagnosis based on a thorough examination. Fractures or dislocations are missed in 11% of patients, and peripheral nerve injuries are missed in 34%. The second is to assume that the patient will make a good neurologic recovery. Basic treatment principles should not be waived on the erroneous assumption that the patient will not survive. The third principle is to anticipate uncontrolled limb motion and lack of patient cooperation. The patient often goes through a period of agitation as neurologic recovery progresses. Traction and external fixation devices are best avoided for extremity injuries. Open reduction and internal fixation of fractures and dislocations diminishes complications, requires less nursing care, allows for earlier mobilization, and results in fewer residual deformities.
Subacute Phase of Neurologic Recovery
During the subacute phase, when the patient is generally in a rehabilitation facility, spontaneous neurologic recovery occurs. During this recovery period, which may last from 12 to 18 months, spasticity is frequently present, and heterotopic ossification may develop. Management is aimed at preventing limb deformities, maintaining a functional arc of motion in the joints, and meeting both the physical and the psychological needs of the patient.
Residual Phase or Period of Functional Adaptation
When neurologic recovery reaches a plateau, the third phase of rehabilitation begins. Medical and surgical management is aimed at correction of residual limb deformities and excision of heterotopic ossification while specialists from various disciplines continue moving toward the goals planned for the individual patient.
THE TEAM APPROACH TO PATIENT CARE AND REHABILITATION
Members of the rehabilitation team are involved in setting short-term goals, which are meant to be accomplished by the time of discharge from the rehabilitation program, and long-term goals, which will take an extended period of time to achieve. The identification of needs and the setting of goals are performed independently by health care workers from each discipline. The team members then meet to discuss their goals and draw up a coordinated plan.
General medical goals are usually straightforward. Because most patients with traumatic brain injuries are younger persons, chronic premorbid illnesses are uncommon. Prevention and treatment of infections are important goals, especially while shunts, tubes, and catheters are in place. If seizures are present, controlling them without causing sedation is vital.
In patients with decreased ROM in a joint, the cause of the problem should be explored. Possible causes include increased muscle tone, pain, myostatic contracture, periarticular heterotopic ossification, an undetected fracture or dislocation, and lack of patient cooperation secondary to diminished cognition. Peripheral nerve blocks with local anesthetics are useful in distinguishing between severe spasticity and fixed contractures.
Phenol blocks or botulinum toxin injections are used to decrease spasticity only during the period of potential neurologic recovery. The rationale for phenol injection is that by the time the nerve regenerates, the patient will have recovered more control of the affected muscle.
The technique for administering the phenol block depends on the anatomic accessibility and composition of the nerve; the direct injection of a peripheral nerve gives the most complete and long-lasting block. If a peripheral nerve has a large sensory component, however, direct injection is not recommended because loss of sensation is undesirable and some patients may develop painful hyperesthesia. In some cases, it is necessary to dissect surgically the individual motor branches of a nerve that runs to a muscle and inject each branch separately. In other cases, the motor points of the muscles can be localized using a needle electrode and nerve stimulator and then injected. Motor point injections do not completely relieve spasticity but can be helpful in reducing muscle tone. The duration of motor point blocks is approximately 2 months, and the blocks can be repeated as necessary.
Botulinum toxin is injected directly into the muscle belly. The onset of action is delayed but lasts for approximately 3 months. The injections can be repeated as needed and do not result in any scarring of the muscle. The limitation of botulinum toxin is the total dose tolerated at a given time and its high cost relative to phenol.
Nursing goals concentrate on basic bodily needs such as nutrition, hygiene, and handling of secretions. Removal of tubes at the earliest possible time is a desirable goal.
Tracheostomy tubes are commonly used in patients with brain injury. General principles of care include changing an uncuffed tube as soon as possible to prevent pressure necrosis of the trachea, adding mist if necessary to provide moisture to the artificial airway, establishing suctioning procedures to prevent trauma and infection, and eliminating the dressing once the tracheostomy incision is healed because the dressing can be a source of infection. The size of the tube is gradually reduced, and the tube is then plugged to tolerance. When continual plugging is tolerated for 3 consecutive days, the tube can be removed.
Feeding tubes are also commonly used. If oral feeding is not anticipated in the near future, a percutaneous endoscopic gastrostomy tube is recommended. If oral feeding is anticipated soon, a nasogastric tube is inserted, cleaned daily, and changed once a week. Instituting and carrying out an oral feeding program requires the combined efforts of the nursing and physical therapy staffs. Head and trunk control are necessary to provide alignment of swallowing structures. The presence of a cough reflex indicates some measure of laryngeal control and the ability to clear the airway. The presence of a swallowing reflex indicates inherent coordination of swallowing structures. The gag reflex, although protective, is not necessary for functional swallowing. Oral feeding should be started with thickened liquids and pureed foods, which provide more oral stimulus and allow time to initiate swallowing. Thin liquids are more easily aspirated.
The ability to inhibit voiding is generally a cognitive function. Restoring continence in the brain-injured patient requires a consistent routine with repeated instructions and positive feedback. Bowel programs should be initiated as soon as the patient begins taking nourishment via the gastrointestinal tract. Again, a consistent routine is most successful.
Cognitive and Neuropsychological Management
The return of cognitive abilities follows the same sequence of stages that normal cognitive development follows, with each new level of cognitive function stemming from the previous level. Table 13–4 shows the eight levels. Cognitive and behavioral management focuses on providing stimulation for patients with a level II or III response; providing structure for patients with a level IV, V, or VI response; and encouraging community activities for patients with a level VII or VIII response.
Memory loss and diminished cognitive function are frequently the most pervasive limitations to overall function. Cognitive retraining is an essential part of the rehabilitation process at every stage. As cognition increases and the patient becomes more aware of the injury, he or she also becomes increasingly aware of the possible consequences of the injury and requires counseling and psychological support.
After traumatic brain injury, patients may have temporary or permanent physical handicaps that prevent them from communicating effectively. In communicating with nonverbal patients, a variety of methods and devices can be used, ranging from yes-and-no signals to communication boards and electronic devices. Patients need to acquire at least a minimal level of attentional, memory, and organizational skills to facilitate use of such communication devices. In verbal patients, language disorders may be present because of an underlying cognitive disruption following head trauma. The most frequent residual language disorders are those seen in the areas of work retrieval and auditory processing. Language therapy in patients with these long-term disorders should be directed toward reorganization of the cognitive process.
Areas of concern in physical therapy include patient positioning, mobility, and performance of daily activities. Making it possible for bedridden patients to sit can significantly improve the quality of life and greatly enhance the opportunities to interact with other people. In some patients, casts or orthotic devices may be required to maintain the desired limb positions. Aggressive joint ROM exercises are necessary to prevent contractures.
Among the factors that influence whether a patient can walk are limb stability, motor control, good balance reactions, and adequate proprioception. Equipment and devices to aid in movement (canes, walkers, wheelchairs, etc.) should always be of the least complex design to accomplish the goal and should be chosen on the basis of the individual patient's cognitive and physical level of function.
In developing appropriate exercises and activities for a patient, the physical therapist should consider factors such as the joint ROM, muscle tone, motor control, and cognitive functions of the patient. Even the confused and agitated patient may respond to simple, familiar functional activities such as washing the face and brushing the teeth. Patients with higher cognitive function should be encouraged to carry out hygiene, grooming, dressing, and feeding activities.
Surgical Management of Residual Musculoskeletal Problems
After neurologic recovery stabilizes, surgical procedures may be indicated to correct residual limb deformities and to excise heterotopic ossification.
CORRECTION OF LIMB DEFORMITIES IN THE LOWER EXTREMITIES
In functional lower limbs, surgery is most often directed at correcting the equinovarus deformity of the foot (see Figure 13–12). The procedures needed for correction of the deformity are determined by clinical evaluation combined with laboratory assessment using dynamic polyelectromyography (poly-EMG). Commonly several procedures are done simultaneously: lengthening of the Achilles tendon (see Figure 13–16), release of the flexor digitorum longus, flexor hallucis longus and flexor brevis tendons (see Figure 13–17), a split anterior tibial tendon transfer (see Figure 13–18), and transfer of the flexor digitorum longus tendon to the heel. The object of surgery is to provide a plantigrade foot for standing and walking, and the surgery is highly successful in this goal. Seventy percent of patients are able to ambulate without a brace after surgery.
A stiff-knee gait is a common deformity that causes the patient to hike the pelvis and circumduct the leg for clearance of the foot during the swing phase of walking. Inappropriate activity in the quadriceps muscle at this time prevents knee flexion. If the vasti muscles of the quadriceps muscle are firing out of phase, the affected head or heads can be lengthened surgically (see Figure 13–14) to allow knee flexion while retaining quadriceps function. Transfer of the rectus femoris muscle to the sartorius or gracilis muscle provides active knee flexion during swing.
In nonfunctional lower limbs, surgery commonly consists of releasing contractures of the hips and knees.
CORRECTION OF LIMB DEFORMITIES IN THE UPPER EXTREMITIES
In functional upper limbs, surgery is frequently needed to correct problems of the wrist, fingers, and thumbs. If active hand opening is restricted by flexor spasticity, lengthening of the extrinsic finger flexors (Figure 13–23) weakens the overactive flexors and improves hand function while preserving the ability of the patient to grasp objects. In cases in which spastic thenar muscles cause thumb-in-palm deformity, a procedure consisting of proximal release of the thenar muscles (Figure 13–24) corrects the problem while preserving function of the thumb. In some patients, adequate placement of the hand for functional activities is impaired by elbow spasticity, although triceps function is generally normal. In these patients, lengthening the elbow flexors (Figure 13–25) enhances the ability to extend the elbow smoothly while preserving active flexion.
In nonfunctional upper limbs, common procedures consist of releasing various contractures and performing neurectomies to eliminate muscle spasticity. The problems of shoulder contracture, elbow contracture, and clenched-fist deformity are discussed in the section on stroke (see previous discussion), and the surgical procedures used in their treatment are shown in Figures 13–20, 13–21, and 13–22.
EXCISION OF HETEROTOPIC OSSIFICATION
Surgical measures for treatment of this problem are discussed later in this chapter.
OCCUPATIONAL THERAPY AND SOCIAL SERVICES
Before patients are released from the hospital or rehabilitation facility, both they and their families must be informed about social service agencies, support groups, and special programs that can be of help. Social adjustment and the resumption of occupational pursuits and leisure activities depend on the recovery of mental factors first, personality status second, and physical factors third. Physical factors are more responsive to rehabilitation than are mental, personality, or social factors. Mental impairment, however, interferes the most with independence in ADLs.
Changes in the rules governing inpatient rehabilitation hospitals and units, particularly the implementation of the new prospective payment system for inpatient rehabilitation facilities by the Centers for Medicare & Medicaid Services (CMS), complicate the admission of patients with rehabilitation goals to an inpatient setting.
Physicians generally agree on the circumstances that justify a medical or surgical patient's hospitalization. In addition, in some cases an admission to a rehabilitation hospital or to the rehabilitation service of a short-term hospital can be justified on essentially the same medical or surgical grounds. In other cases, however, a patient's medical or surgical needs alone may not warrant inpatient hospital care, but hospitalization may nevertheless be necessary because of the patient's need for rehabilitative services.
Patients needing rehabilitative services require a hospital level of care if they need a relatively intense rehabilitation program that requires a multidisciplinary coordinated team approach to upgrade their ability to function (eg, patients with traumatic brain injury or SCI after corrective extremity surgery). Two basic requirements must be met for inpatient hospital stays for rehabilitation care to be covered:
To meet the requirements just cited, the following basic components must be met:
Heterotopic ossification is commonly detected 2 months after traumatic brain injury or SCI and is characterized by increasing pain and decreasing ROM about a joint. The problem affects adults but is virtually unheard of in children. Although the cause of heterotopic ossification is unknown, a genetic predisposition is suspected. Unidentified humoral factors that enhance osteogenesis are demonstrated in the sera of patients with brain injury. Other contributing factors include soft-tissue trauma and spasticity.
Clinically significant heterotopic ossification is seen in 20% of adults with traumatic brain injuries or spinal cord injuries and may affect one joint or multiple joints. The overall rate of joint ankylosis is 16%. In affected patients, the bone forms in association with spastic muscles, and the alkaline phosphatase level is elevated. Bone scans may aid in early diagnosis, and the diagnosis is most commonly confirmed by radiographs.
In 27% of patients with heterotopic ossification, shoulder involvement is found inferomedial to the glenohumeral joint. Although ankylosis of the joint in these cases is unusual, motion may be sufficiently restricted to require surgical resection. Elbow involvement is seen in 26% of patients with heterotopic ossification and in 89% of those who suffered a fracture or dislocation about the elbow. When ossification forms posterior to the elbow joint, pressure neuritis of the ulnar nerve is common. Anterior transposition of the ulnar nerve is frequently required to prevent entrapment, and this procedure also facilitates later bone resection. Joint ankylosis is a common complication in patients with elbow involvement. Hip involvement is seen in 44% of patients who form ectopic bone. Bilateral hip involvement and joint ankylosis are common in these patients. Heterotopic ossification in the knee joint is less common but significantly impedes both flexion and extension of the joint.
Aggressive treatment of spasticity is necessary because this problem appears to play an etiologic role in mechanically stimulating bone formation. To eliminate spasticity in the muscle groups adjacent to the bone formation, phenol blocks are administered. To prevent the deposition of calcium crystals in the collagen matrix of the periarticular connective tissue, etidronate disodium (Didronel) is used. When the heterotopic bone is detected very early, the use of intravenous etidronate sodium, 300 mg for 3 days, followed by oral therapy is very effective. The recommended dosage is 20 mg/kg/day orally in a single dose, and the drug should be taken on an empty stomach for proper absorption. Antiinflammatory medications are also used to control the intense inflammatory reaction that occurs during the formation of heterotopic bone. The most commonly documented medication is indomethacin, 75–150 mg daily, but in theory, other medications are equally effective. Physical therapy is aimed at providing gentle ROM to the joint to prevent ankylosis. Forceful joint manipulation is not advised because it can cause fractures or soft-tissue damage with contracture formation.
Surgical excision is the definitive treatment for heterotopic ossification. To prevent recurrence of the problem, excision should be delayed until the heterotopic bone is fully mature. A true bone cortex should be visible radiographically. The serum alkaline phosphatase level does not need to be normal. If the patient has voluntary motion about the joint, surgical excision predictably results in an increased ROM. Following surgery, a single dose of radiation therapy (800 rads) and oral etidronate therapy for 6 weeks is used to prevent recurrence. Physical therapy is continued after surgery.
Rheumatoid arthritis (RA) is a systemic disease that affects connective tissue and results in chronic inflammatory synovitis. The cause of the disease remains unknown. An infectious agent, perhaps viral, is suspected to be the initiating factor. A genetic predisposition may also be a factor.
Immune mechanisms are involved, as evidenced by the presence of large numbers of lymphocytes in the synovial tissue and by the presence of rheumatoid factor (IgM antibodies) in the serum and synovial fluid of 80% of patients. The antigen-antibody reactions activate the complement system and attract neutrophils to the joint fluid. The immune complexes are then phagocytized, and lysosomal enzymes are released into the synovial fluid. These enzymes and the inflammatory synovial pannus are in part responsible for the destruction of articular cartilage and periarticular structures. Tendons are also directly invaded by the inflammatory synovium and may attenuate and rupture. Ligaments and joint capsules become weakened by the chronic inflammatory process and may become stretched by repeated joint effusions (Figure 13–26).
The erosion of articular cartilage is greatly enhanced by the superimposition of mechanical derangements on a joint weakened by chronic inflammation and enzymatic deterioration. Osteoporosis results from the hyperemia of inflammation. Disuse of limbs secondary to pain, weakened muscle action, and mechanical derangements enhances the osteoporosis.
RA affects synovial joints, bones, muscles, fasciae, ligaments, and tendons. Because it is a systemic disease, it can also affect internal organs. The diagnosis is made primarily on clinical grounds and supported by radiographic and laboratory data (Table 13–5). RA is two or three times more common in women than men. The disease is seen in some children but has increasing prevalence with increasing age up to the seventh decade. Rheumatic complaints are responsible for the largest share of chronic disability in the United States.
The clinical course of RA is variable with respect to the extent and intensity of the disease. The time course of the disease, measured in months and years, is progressive. Several factors affect the course of disease and are associated with a poor prognosis. These factors include insidious onset, symmetric disease, presence of rheumatoid factor in the serum, and presence of rheumatoid nodules, which occur in patients with rheumatoid factor. In patients under 40 years of age, with RA, females have a worse prognosis than males. Eosinophilia of 5% or greater is associated with an increased incidence of vasculitis, pleuropericarditis, pulmonary fibrosis, and subcutaneous nodules.
The multisystem nature of RA and its variable clinical pattern make it difficult to devise a precise system for describing the overall functional ability of the patient. The most commonly employed scale is the functional classification devised by the American Rheumatism Association (Table 13–6).
THE TEAM APPROACH TO PATIENT CARE AND TREATMENT
Optimal management requires an interdisciplinary team approach involving many specialists, including a liaison nurse, rheumatologist, orthopedic surgeon, physical therapist, occupational therapist, psychologist, and social worker. The patient and members of his or her family are also important members of the team. Because the disease is an ongoing and progressive process, the goal of management is to prevent deformities and maintain function for the patient over a lifetime.
Nursing Care and Patient Education
The liaison nurse functions as the coordinator of the team. The nurse provides the critical link between the inpatient medical and surgical management of the disease and the continuation of treatment in the outpatient environment.
Much of the responsibility for patient education in the daily care of the disease rests with the nurse, who explains the techniques for protecting joints; advises patients about the need to perform exercises for maintaining joint ROM and optimizing failing muscle strength; cautions patients that exercising too vigorously can damage weakened joints and ligaments; and reminds patients that because the disease tends to decrease their physical activity, they will need regular periods of rest during the day and good nutrition to maximize their general health and to prevent obesity.
Medical and Surgical Management
The rheumatologist is commonly the team leader and in charge of medical management, which is directed toward the control of synovitis, the relief of pain, and the prevention or treatment of other organ involvement by the disease. The medications used for treatment include aspirin, nonsteroidal antiinflammatory drugs (NSAIDs), corticosteroids, immunosuppressive drugs, and suppressive agents. A local injection of corticosteroids can be useful in controlling an acute inflammatory process in a specific joint. Corticosteroids can also be used systemically but are generally avoided because of undesirable side effects. Agents that produce suppression or remission of arthritis inclumde gold salts, antimalarial drugs, and penicillamine. Immunosuppressive drugs or total lymphoid irradiation can also be used to suppress immune reactions. The most important measure to treat RA successfully is the use of disease-modifying antirheumatic drug (DMARDs), which can retard or prevent disease progression and, thus, joint destruction and subsequent loss of function. Until the full action of DMARDs takes effect, antiinflammatory or analgesic medications may be required as bridging therapy to reduce pain and swelling. DMARDs can be classified into xenobiotic and biologic agents. Methotrexate (MTX) and sulfasalazine (SSZ) are the most active xenobiotic compounds in terms of frequency of remissions and time to onset of action and provide the best risk-benefit ratios. MTX alone or in combination with other agents is now the standard of care for moderate-to-severe RA.
The recognition of TNF- and IL-1 as central proinflammatory cytokines led to the development of biologic agents that block these cytokines or their effects. The first such biologics were the TNF blockers etanercept and infliximab. These agents are expensive. Consensus statements do not recommend their use until at least one xenobiotic DMARD, usually MTX, was administered without sufficient success. A new addition to the biologics is anakinra (interleukin-1 receptor antagonist [IL-1RA]). IL-1RA occupies the IL-1 receptor without triggering it and prevents receptor binding of IL-1.
The orthopedic surgeon should be involved early in the course of the patient's disease and not merely be called on when medical management fails to be effective. A knowledge of biomechanics, gait dynamics, and energy requirements can be useful in preserving function for the patient. The orthopedist can often recommend orthotic supports, walking aids, and shoe wear that minimize unwanted stress on joints and maximize strength.
In selected situations, early surgical intervention may prevent excessive deterioration of joint structure and function. Synovectomy is effective in preventing tendon rupture in the hand, whereas arthroscopic synovectomy of the knee and shoulder show promise for preventing joint destruction. Fusion of an unstable cervical spine can prevent the disastrous effect of a SCI.
Most surgical procedures are reconstructive. Because relief of pain is the most consistent result of reconstructive surgery, pain is the primary indication for surgery. Restoration of motion and function and the correction of deformity are additional indications for surgical intervention but are more difficult goals to achieve. Preoperative assessment is a painstaking process. In addition to performing a physical examination and reviewing radiographic findings, the surgeon must attempt to elicit sufficient information from the patient, family, and therapists to ascertain which deformities are causing the greatest functional losses. The patient can only tolerate a finite number of surgical procedures, and these must be carefully staged to obtain the maximal result.
For further discussion of medical and surgical treatment, see the section Management Approaches Based on the Area of Disease Involvement.
The physical therapist uses modalities such as heat and ultrasound to decrease joint stiffness and relieve pain. An exercise program is essential for preserving the functional abilities of the patient. The exercise should gently put all joints through their full arc of motion to maintain this range.
Patients with joint effusions and synovitis automatically assume positions that minimize intraarticular pressure and therefore minimize pain. These positions are usually not optimal for function and can result in flexion deformities. An abnormal position may be reversible if discovered early. Daily joint ROM exercises are central to preventing unwanted contractures.
Muscles weakened by the concomitant myopathy need strengthening but are susceptible to damage from overuse or from an excessively vigorous exercise program. Orthotics may be indicated to support weakened ligaments and provide a means of joint protection and support for functional activities such as walking. Upper extremity walking aids may be useful to give the patients additional support. These aids often require modification to meet the specific needs of the individual. Forearm troughs allow the patient to use the entire arm for support when the hands and wrists are weak or deformed. They are also useful for protecting the hands from excessive stress. A rolling walker, which does not require the patient to lift the walker for advancement, may be useful in patients with limited strength.
The occupational therapist evaluates and instructs the patient in modified techniques for performing ADLs, such as grooming, dressing, and meal preparation. Because of the weakness and deformities imposed by the arthritis, adaptive equipment and alternative methods are commonly needed. Modifications in clothing, such as larger fasteners for ease of manipulation, Velcro strips at seams or on shoes, and front openings, can all facilitate dressing. Upper extremity splints can be used to provide joint protection and stabilization and to prevent further deformity from occurring. The splints must be lightweight and easily donned by the patient.
It is not uncommon for patients or their family members to have feelings of anxiety, denial, anger, or depression. The psychologist provides assistance in dealing with these feelings and coping with alterations in lifestyle and self-image. Comprehensive care involves an understanding of how patients respond to weakness, fatigue, altered physical appearance, progressive disability, diminished independence, and the financial burdens of chronic illness. Coping skills are needed to deal with these problems as well as with pain, which becomes an everyday occurrence and may interfere with both intellectual and emotional functioning.
A variety of modifications in lifestyle accompany chronic illness with RA. Occupational changes may be necessary, or the patient may no longer be able to work at all. Additional assistance may be needed in the home for housework and the preparation of meals. In more advanced stages, the patient may require help for personal care. Transportation needs become more complex, and the patient finds it increasingly difficult to leave the home. The social worker becomes an invaluable team member in helping families with the numerous practical arrangements required for everyday existence and for locating financial aid to help defray the mounting costs.
MANAGEMENT APPROACHES BASED ON THE AREA OF DISEASE INVOLVEMENT
Orthopedic surgery is frequently necessary for patients with RA affecting the cervical spine or extremities.
Depending on the study and diagnostic criteria, involvement of the cervical spine is found in anywhere from 6.4% to 90% of patients with RA. Three forms of cervical spine involvement are seen.
The first and most common form is atlantoaxial instability (Figure 13–27), which results from erosion of the transverse and alar ligaments. These ligaments normally function to maintain the odontoid process of the axis within the anterior third of the atlas ring, where the two bones articulate with each other. Disruption of the transverse and alar ligaments results in excessive motion between C1 and C2. Forward flexion of the head causes anterior subluxation of the atlas on the axis and possible impingement of the spinal cord or occlusion of the vertebral arteries. This is best seen in lateral flexion and extension radiographs of the cervical spine.
The second form of cervical spine involvement is subaxial instability (Figure 13–28), which may lead to subluxation of two or more cervical vertebrae below the level of C2. If subluxation is severe or its appearance is sudden, it can exert sufficient pressure on the spinal cord to cause permanent quadriparesis. If subluxation occurs slowly over a long time, however, as commonly happens, the spinal cord is able to adapt to the pressure, so that a severe degree of deformity occurs before clinical symptoms appear.
The third and least common form of cervical spine involvement is superior migration of the odontoid process of C2 resulting from severe degrees of bone erosion. This form of involvement is reported in from 3.8% to 15% of patients with RA. As the dens migrates proximally, radiographic detail is lost because of the overlapping of bony structures. CT scanning is most useful in elucidating the exact nature of the involvement and can show rotational instability caused by asymmetric bone erosions (Figure 13–29).
Orthotic supports are useful in controlling the patient's symptoms. Posterior cervical fusion is indicated when the spinal cord is at risk of damage. The most common level of fusion is C1 to C2, supplemented by wire fixation. If the subluxation is irreducible or if severe osteoporosis is present, fusion to the occiput may be necessary. Occasionally, it is useful to supplement the bone graft with polymethyl methacrylate fixation.
In patients with severe erosive disease of the cervical spine and proximal migration of the odontoid process, a rotational deviation of the larynx may occur, making intubation impossible except with the use of a flexible fiber optic scope (Figure 13–30). Because cervical spine disease often presents difficulties in endotracheal intubation at the time of surgery, the stability of the cervical spine should be assessed preoperatively in all patients with RA. Lateral flexion-extension radiographs taken within 1 year of surgery are sufficient to detect significant instability problems. Use of the flexible fiber optic bronchoscope for such problems is valuable. Among the indications for fiber optic intubation in patients with arthritis are an unstable cervical spine on flexion and extension; limited mobility of the cervical spine; and impaired motion of the temporomandibular joints, with or without associated micrognathia.
Total joint replacement has vastly improved the quality of life for patients with RA. Special problems exist in this group of patients, however, and must be considered before total hip arthroplasty is performed. Because osteoporosis is pronounced, fracture can occur easily during surgery. Protrusio acetabuli, another common problem, may require bone grafting. The risk of infection is increased in this population, and wound healing may also be delayed, especially if the patient has been taking systemic corticosteroids. In patients under the 60 years, excess femoral anteversion may be present and distort the anatomy. Moreover, the small size of the bone may require a special prosthesis. Despite these problems, total joint arthroplasty remains the treatment of choice for the arthritic hip.
Knee pain is common and may be the result of a valgus deformity of the hindfoot, which places excessive stress on the knee proximally. Mild medial knee pain can be relieved with the use of an AFO to correct the valgus deformity. Knee pain may also be caused by the presence of a joint effusion, which increases the intraarticular pressure and thereby increases the pain. When patients attempt to minimize pain by placing the knee in 30 degrees of flexion, this encourages the formation of flexion contractures.
Arthroscopic evaluation of the rheumatoid knee demonstrates the importance of the meniscus in the degeneration of the knee. The synovium directly invades the body of the meniscus and tears it. The mechanical derangement resulting from the torn meniscus then causes rapid deterioration of the articular surfaces, which were rendered abnormal by the action of enzymes. Synovectomy of the joint line and partial meniscectomy are easily accomplished under arthroscopic control and may have a role in preventing articular damage in the rheumatoid knee.
Total knee arthroplasty is effective in restoring knee alignment and motion and relieving pain. When a valgus deformity is present, serial releases of the soft tissue should be performed to realign the limb prior to cutting the bone for insertion of the prosthetic components. The lateral retinaculum, popliteal tendon, proximal iliotibial band, posterolateral capsule, and lateral collateral ligament can be released in this sequence to provide soft-tissue balance. A flexion deformity is corrected at the time of arthroplasty by releasing the posterior capsule from the femur or by removing additional bone from the distal femur in severe cases.
Forefoot involvement is common in RA. Clawtoe deformities with plantar subluxation of the metatarsal heads result in painful callosities on the plantar surface of the forefoot. These problems are usually accompanied by a hallux valgus deformity. Skin ulcerations may form over bony prominences. Forefoot pain prevents the patient from transferring body weight over the foot during terminal stance, which results in an awkward gait with a shortened step length. Extra-depth shoes with wide toe boxes and molded pressure-relieving inserts may be sufficient to relieve pain and improve gait. When the deformities are marked, resection of the metatarsal heads in conjunction with arthroplasty or fusion of the metatarsophalangeal joint of the great toe is indicated.
Hindfoot involvement is also common and results in a planovalgus or pronation deformity. A longitudinal arch support or similar shoe insert is not sufficient to hold the hindfoot in alignment. When the deformity is supple, an AFO with a well-molded arch support can control the position of the heel and subtalar joint during gait. This also reduces the valgus thrust on the knee joint. If the deformity is fixed, a triple arthrodesis aligns the hindfoot.
In patients with RA, shoulder involvement is common but is generally insidious in onset or episodic in nature. Because the pain is not constant early in the course of the disease, shoulder involvement is often not appreciated until a significant amount of destruction occurs. The shoulders must be examined regularly to detect early loss of motion and function.
Arthroscopy provides a useful tool in examining the shoulder and assessing the integrity of the glenoid labrum, rotator cuff, and biceps tendon. Arthroscopy can also be used to perform synovectomy of the shoulder joint.
Normally, the glenohumeral joint has more motion than any other joint. This motion is rotation, and it is facilitated by the shallow shape of the glenoid labrum. The rotator cuff muscles, which are central to the normal functioning of the shoulder, provide stability to the humeral head and also provide rotation. If the rotator cuff ruptures, the humeral head rides upward and is subjected to abnormal muscle forces as the patient attempts to compensate for the loss of motion. This results in the rapid deterioration of the glenohumeral joint. Normally, the anterior portion of the deltoid muscle provides forward elevation of the humerus. This is the position of function and the most common arc of motion for activities involving the upper extremity. The tendon of the long head of the biceps muscle serves to stabilize the humeral head against riding upward and also to reduce subacromial impingement. Whenever surgery of the shoulder is performed, it is important to preserve the deltoid muscle fibers and their attachments as well as the intraarticular portion of the biceps tendon.
The subacromial bursa is often involved with the inflammatory response of RA and may become thickened. The inflammatory process may cause a decrease in nutrition of the rotator cuff tendons and lead to attrition of the tendons with or without rupture of the rotator cuff. Subacromial bursitis can be treated by local injection of a corticosteroid preparation. When the inflammation subsided, the patient is begun on a program of gentle ROM exercises.
Repair of a ruptured rotator cuff is often possible and should be performed. If the rupture is detected early, excessive damage to the glenohumeral joint can be avoided. If extensive joint damage is already present, repair or reconstruction of the rotator cuff is done at the time of prosthetic arthroplasty of the glenohumeral joint. Preoperative radiographic evaluation should include axillary radiographs to assess the glenoid alignment. The glenoid labrum is often eroded asymmetrically, and the prosthetic component must be accurately aligned to ensure optimal function and to minimize the abnormal forces that might lead to prosthetic loosening. In patients with total shoulder replacement, pain is effectively alleviated. Shoulder function depends on the integrity of the soft tissues and on muscle function. Resurfacing of the glenoid should be reserved for those patients with an intact rotator cuff. If the rotator cuff is destroyed, humeral hemiarthroplasty is the preferred surgical treatment. A careful postoperative therapy program is essential for maximizing shoulder function.
The elbow joint consists of three separate articulations: radiocapitellar, ulnotrochlear, and radioulnar. These articulations allow the hand to rotate 180 degrees around the longitudinal axis of the forearm. The function of the hand depends on being placed in space as necessary for use. The elbow is the most important joint for positioning the hand. Unlike the shoulder or wrist, if the elbow is fused, the functional loss is great. The goal of treatment is to maintain a painless arc of motion.
Olecranon bursitis is common in patients with RA. The usual treatment consists of aspirating the bursa and injecting a corticosteroid preparation. Rarely, chronic bursitis develops and requires surgical excision of the bursa.
Subcutaneous rheumatoid nodules are common along the extensor surface of the ulna. The nodules are often sensitive to pressure when the arm is resting on any surface, and they may interfere with the use of forearm troughs on walking aids. If they are bothersome, the nodules should be excised surgically. The patient should be advised, however, that nodules can recur.
Radiocapitellar arthritis is often the predominant feature of elbow involvement and can cause marked pain and a decrease in motion. The pain is most pronounced with pronation and supination of the forearm.
When the joint destruction is severe, prosthetic arthroplasty is indicated. Elbow prostheses fall into two basic categories: semiconstrained and unconstrained. An unconstrained design is less likely to loosen. The shoulder should be evaluated carefully prior to prosthetic elbow arthroplasty. A patient with limited shoulder motion exerts greater forces on the elbow in an effort to compensate for the decrease in shoulder function.
WRISTS AND HANDS
In patients with RA, evaluating the wrist and hand deformities and developing a rational treatment plan can be a complex task for the surgeon. Many joints, tendons, and ligaments are involved in a linked system of structure and function. Treatment can be divided into three categories: nonsurgical treatment, preventive surgery, and reconstructive or salvage surgery. Nonoperative treatment consists of resting inflamed joints; exercising joints for short periods of time but frequently and gently to maintain motion; using resting or dynamic splints to alleviate pain and prevent deformity; and judiciously using local corticosteroid injections for control of synovitis.
Dorsal tenosynovitis is common. It is of significance because it often results in rupture of the extensor tendons either from attrition or from direct invasion of the inflamed synovial tissue into the tendon substance. Tenosynovectomy should be performed in patients whose synovitis has persisted for 4–6 months despite medical treatment. Recurrence of the synovitis is rare following synovectomy, and the procedure prevents extensor tendon rupture.
Rupture of an extensor tendon can result from attenuation of the tendon caused by chronic inflammation, friction against abnormal bony surfaces, ischemia secondary to interference with the normal circulation to the tendon, or direct invasion of the tendon by synovium. The most common tendons to rupture, listed in order of frequency, are the extensors of the fifth finger, the extensors of the ring finger, and the long extensor of the thumb (the extensor pollicis longus). Surgical repair by tendon transfer is more successful when fewer tendons are involved. Therefore, prompt diagnosis and treatment are essential for a successful outcome. For a single tendon rupture in the fifth and ring fingers, a side-to-side repair using the adjacent extensor tendon is advised. The tendon of the index finger extensor can be transferred to repair a rupture of the thumb extensor tendon or a rupture of two finger tendons. For more complex ruptures, tendon transfer from the wrist extensors or from the superficial flexor muscles of the fingers may restore function.
Synovitis in the flexor tendon sheaths is characterized by crepitation that is palpable in the palm during finger flexion and extension. Triggering of the fingers may result from the inflamed synovial tissue catching on the flexor pulleys with motion. Carpal tunnel syndrome may also occur as a result of swelling within the carpal canal, which causes pressure on the median nerve. Early treatment consists of local corticosteroid injection to reduce the inflammation, application of a splint, and medical management of the underlying synovitis. Persistent synovitis may require carpal tunnel release and synovectomy. Rupture of the flexor tendons is rare.
The wrist joint is a frequent site of synovitis and may begin to show radial deviation and volar subluxation. The radioulnar joint is commonly inflamed and painful. Early treatment consists of splinting for support and medical control of the synovitis. Dorsal synovectomy of the extensor compartments is indicated when medications do not control the synovitis adequately. Dorsal synovectomy prevents rupture of the extensor tendons. Radial deviation of the carpus can be corrected by transfer of the extensor carpi radialis longus tendon to the extensor carpi ulnaris.
When the wrist becomes unstable, several choices of surgical treatment are available. If the deformity is mild, bone stock can be preserved and motion maintained by a limited carpal fusion. The lunate and scaphoid bones are fused to the distal radius to prevent further displacement of the carpus. The distal ulna can be fused to the distal radius to provide a platform to support the wrist. A segment of the ulna is removed just proximal to the fusion to allow for pronation and supination of the forearm. If the intercarpal joints are severely affected by the arthritis, the base of the capitate bone can be removed and a tendon spacer inserted to preserve motion at the intercarpal row.
Another option is to perform a prosthetic arthroplasty of the wrist. More bone stock is removed with this procedure, but revision is still possible in the event of fracture of the prosthesis. Several designs of total joint prosthesis are available for the wrist.
Fusion of the wrist joint provides a stable pain-free joint and remains a reasonable surgical choice for selected patients. Because fusion may interfere with personal hygiene tasks, it is advisable to avoid fusing both wrist joints.
Metacarpophalangeal and Carpometacarpal Joints
Finger and wrist deformities commonly occur together in a collapsing zigzag pattern. The wrist deviates in a radial direction, and the fingers then drift ulnarward at the metacarpophalangeal joint level. When both deformities are present, the wrist must be realigned prior to correcting the finger deformities, or the ulnar deviation of the fingers recurs.
Ulnar deviation and volar subluxation of the fingers at the metacarpophalangeal joint level are common. With ulnar deviation, the extensor tendons move into the valleys between the metacarpal heads. This condition can be confused with extensor tendon rupture. If the joint surfaces are preserved, function can be improved by a synovectomy, soft-tissue release of the volar capsule, and realignment of the extensor tendons. If the joint surfaces are destroyed, then a total wrist arthroplasty can be considered. If the joints are unstable because of ligament loss, it may be necessary to reconstruct the radial collateral ligament using a portion of the volar plate to provide a stable pinch. Tightness of the intrinsic tendons commonly occurs in conjunction with the subluxation of the metacarpophalangeal joints. To correct this problem, a release of the intrinsic tendons is performed along with the arthroplasty. Dynamic splinting of the fingers, which maintains alignment while allowing motion, is used continuously for 6 weeks following surgery and then for an additional 6 weeks at night.
Flexion of the metacarpophalangeal joint with extension of the interphalangeal joint in the thumb is the equivalent of a boutonnière deformity. The reverse deformity can also be seen, with extension of the metacarpophalangeal joint and flexion of the interphalangeal joint. An adduction deformity of the metacarpal bone places increased stress on the metacarpophalangeal joint and produces lateral instability and hyperextension. Adduction of the thumb occurs when the carpometacarpal joint shifts radially. Derangements of the carpometacarpal joint can be treated by fusion or by arthroplasty. Interposition arthroplasty is desirable to maintain motion and can be performed using a Silastic spacer or soft tissue.
Continued synovitis gradually attenuates the capsular and ligamentous structures and results in tendon imbalance. In the fingers, this will be seen as either a flexion or an extension deformity.
Flexion deformity results from rupture or attenuation of the central slip of the extensor mechanism, with gradual volar displacement of the lateral bands. As the lateral bands shift in the volar direction, a hyperextension deformity of the distal interphalangeal joint results. This flexion malalignment, called a boutonnière, or buttonhole, deformity, interferes with the ability to grasp large objects but does not usually impede the pinch function used for picking up small items. Interposition arthroplasty using a Silastic spacer gives unpredictable results. Fusion of the interphalangeal joints gives dependable results when the boutonnière deformity is fixed. In the index and long fingers, stability for pinch is required for good function and is more important than a large arc of motion. In the ring and small fingers, motion is more important for a functional grasp. When arthroplasty is considered, the ring and fifth fingers are usually selected.
Hyperextension deformities, or swan-neck deformities, can be either primary or secondary. Primary deformities are caused by stretching of the volar plate from synovitis or rupture of the flexor digitorum superficialis tendon. Secondary deformities are characterized by flexion of the metacarpophalangeal joints, with tightness of the intrinsic muscles proximally and presence of a mallet deformity distally. This hyperextension deformity interferes with picking up small objects but does not cause much difficulty with grasping larger objects. If the deformity is treated early and is secondary to intrinsic muscle tightness, a release of the intrinsic tendons corrects the imbalance. If the deformity is seen late and is rigid, joint fusion or arthroplasty is indicated.
Derangements of the distal interphalangeal joints are either mallet deformities secondary to rupture of the extensor tendon or lateral deformities from loss of capsular and ligamentous support. When the deformities interfere with function, fusion of the joint is indicated.
Poliomyelitis is caused by an enterovirus that attacks the anterior horn cells of the spinal cord. Infection can lead to a variety of clinical findings, ranging from minor symptoms to paralysis. The last major epidemics in the United States occurred during the early 1950s. Because of effective immunization programs, acute poliomyelitis has now become rare in the United States and other developed nations of the world. Nevertheless, orthopedic surgeons today are frequently called on to treat patients with postpoliomyelitis syndrome.
Four stages of poliomyelitis are recognized.
All of the anterior horn cells are attacked during the acute stage, which accounts for the diffuse and severe paralysis seen with the initial infection. The anterior horn cells control the skeletal muscle cells of the trunk and limbs. Clinically, the infection is characterized by the sudden onset of paralysis and the presence of fever and acute muscle pain, often accompanied by stiff neck. Paralysis of the respiratory muscles is life-threatening in the acute stage. When the shoulder muscles are involved, respiratory compromise should be suspected because of the close proximity of the anterior horn cells controlling each in the spinal cord. Mechanical support of ventilation may be required.
A variable number of anterior horn cells survive the initial infection. The treatment in the acute stage of the disease consists of providing the needed respiratory support, decreasing muscle pain, and performing regular ROM exercises to prevent the formation of joint contractures.
Anterior horn cell survival, axon sprouting, and muscle hypertrophy occur in the subacute phase and provide three mechanisms for regaining strength. An average of 47% (range of 12–94%) of the anterior horn cells in the spinal cord survive the initial attack. Because cell survival occurs in a random fashion, the distribution of paralysis is variable and depends on which anterior horn cells were destroyed. Each anterior horn cell innervates a group of muscle cells. When a group of muscle cells is orphaned, as it were, by the death of the anterior horn cell that supports it, a nearby nerve cell can sprout additional axons and adopt some of the orphaned cells. By means of this process, a motor unit (defined as a nerve cell and the muscle cells it innervates) can expand greatly. Moreover, muscle cells in the unit enlarge, and this hypertrophy provides additional strength for the patient.
It is only after 16–24 months following onset that the ultimate extent of poliomyelitis can be determined and procedures to restore lost function and provide structural stability can be instituted.
Patients who had acute poliomyelitis during childhood often complain of increased muscle weakness 30–40 years later. This weakness is not a result of infectious spread of the earlier disease but, rather, is caused by the overuse of muscles that were originally affected, whether or not they were known to have been affected at the onset of the disease. Studies show that a muscle must lose from 30% to 40% of its strength for weakness to be detected using manual muscle testing. Studies of gait also demonstrate that the ADLs require more muscle strength and stamina than were previously appreciated. The traditional program, which encouraged patients to work harder to regain strength and was based on the concept of "no pain, no gain," proved detrimental because it encouraged chronic overuse of muscles and resulted in further deterioration of function.
The diagnosis of postpoliomyelitis syndrome is based on a history of poliomyelitis; a pattern of increased muscle weakness that is random and does not follow any nerve root or peripheral nerve distribution; and the presence of additional symptoms such as muscle pain, severe fatigue, muscle cramping or fasciculations, joint pain or instability, sleep apnea, intolerance to cold, and depression. No pathognomonic tests for the syndrome are currently available. Electromyography can demonstrate the presence of large motor units resulting from the previous axon sprouting. This finding is supportive but not diagnostic of poliomyelitis.
When the shoulder muscles are involved, respiratory compromise should be suspected, and mechanical support of ventilation should be instituted. Other measures are aimed at decreasing muscle pain and preventing complications. Regular ROM exercises prevent the formation of joint contractures.
During the subacute stage, which may last as long as 24 months, the emphasis is on preventing deformities and preserving function. Splints and braces are often helpful for maintaining joint position and supplementing function.
Patients with compromised function of the diaphragm can be taught glossopharyngeal breathing. This method, in which air is swallowed into the lungs, provides sufficient air exchange for the patient to perform light activities in the sitting position. Mechanical support of ventilation may still need to be continued while the patient sleeps. It is during the residual stage that orthopedic surgery is commonly performed to restore lost function and provide structural stability. If the patient is still growing, it is important to prevent the formation of skeletal deformities that result from muscle imbalance. Before any surgery that requires general anesthesia or significant sedation is performed, the vital capacity should be assessed to determine the patient's need for respiratory support.
Treatment is directed at preserving current muscle strength and preventing further weakness from occurring. Generally, strength cannot be restored in a muscle that was weakened by poliomyelitis. Some gain in strength can be seen, however, when chronic overuse is corrected.
General management strategies consist of modifying lifestyle to prevent chronic overuse of weak muscles; instituting a limited exercise program that incorporates frequent rest periods to prevent disuse atrophy and weakness; providing lightweight orthotic support of the limbs to protect joints and substitute for muscle function; and performing orthopedic surgery to correct limb or trunk deformities.
Specific management strategies depend on the areas of disease involvement.
Back pain is a common complaint and usually results from postural strain caused by excessive lumbar extension in patients who have weak or paralyzed hip extensor muscles. Neck pain, like back pain, is a common complaint associated with slowly increasing weakness. Both complaints can be treated by the use of external supports. Patient education is imperative because many patients are reluctant to don braces again, after having passed decades without using them. Patients should be instructed in methods to relieve excess strain on the neck muscles and prevent further deterioration. Tilting the seat of a chair 10 degrees backward is often sufficient to relieve the fatigue of the posterior cervical muscles from supporting the head.
Paralysis of the cervical spine musculature can result in the inability to maintain the head erect and can interfere with the performance of a vast number of functions, including ambulation. Surgical fusion of the cervical spine corrects the problem.
Scoliosis is common in patients with muscle imbalance caused by paralysis. The condition is particularly pronounced in patients with leg-length discrepancies. External supports can be used to hold the spine in position, but these often interfere with respiration if the patient depends on the use of accessory muscles for breathing. Posterior spinal fusion may be needed to control the spine adequately. After fusion is performed, prolonged immobilization must be avoided. Segmental spine fixation may be helpful.
Full ROM of the hip and knee joints is needed for function. Contractures should be corrected when possible to permit more effective bracing. In iliotibial band contractures, which are common deformities, the hip assumes a position of flexion, external rotation, and abduction; the knee assumes a valgus alignment; and the tibia is externally rotated on the femur. Release or lengthening of the iliotibial band corrects the deformity.
A patient with flailing lower extremities can stand using crutches and a KAFO with the knees locked in extension and the ankles in slight dorsiflexion by hyperextending the hips and using the strong anterior hip capsule for support. Flexion contractures of the hips or knees prevent this alignment. If trunk support and upper extremity strength are adequate, the patient could ambulate with a swing-through gait for short distances. This gait has high energy demands. With time, the posterior knee joint capsule becomes stretched, and the knee develops a recurvatum deformity that is painful and can lead to arthritic degeneration of the knee. A KAFO protects the knee and provides improved stability for walking. If there is fair (grade 3) strength in the hip flexor muscles (see Table 13–1) and passive full-knee extension, then the knee joints can be left unlocked for walking. In this case, a posteriorly offset knee joint is used to stabilize the knee, and ankle dorsiflexion is limited to minus 3 degrees of neutral dorsiflexion to provide a hyperextension moment to the knee for stability. Thus, at stance phase, the net ankle plantarflexion locks the knee in hyperextension, restrained by posterior capsular static structures.
Quadriceps muscle strength is not essential for ambulation. A strong gluteus maximus and good calf strength can substitute by keeping the knee locked in extension. If the calf strength is inadequate to control the forward motion of the tibia in mid to late stance, an AFO is needed. It is not necessary to fix the ankle in mild plantarflexion to provide knee stability, and such a position could cause a recurvatum deformity in any case. An equinus position of the foot inhibits forward momentum and limits step length by preventing body weight from rolling over the forefoot prior to contact of the contralateral extremity with the ground. When good hamstring function is present, the biceps femoris and the semitendinosus can be transferred anteriorly to the quadriceps tendon to provide dynamic knee stability.
Muscle imbalances in the foot can lead to deformity. When muscle imbalances exist, tendon releases or transfers should be considered prior to the development of fixed deformities.
Equinus contracture of the ankle is a common problem and results in genu recurvatum. Accommodating the equinus posture by using an elevated heel places excessive stress on the calf muscles to control the leg. A surgical procedure to lengthen the Achilles tendon is frequently needed to correct the equinus contracture of the ankle and to permit adequate bracing.
A cavus foot deformity causes forefoot equinus, which also limits bracing. If no fixed bony abnormalities are present, then release of the plantar fascia is sufficient to correct the deformity. If the cavus deformity is caused by bony abnormalities, then a closing wedge osteotomy is needed. A triple arthrodesis of the hindfoot can also be used to correct deformities and provide a stable base of support.
The long-standing muscle imbalances, patterns of muscle substitution, and resulting joint and ligament strains often lead to degenerative arthritis. Total joint replacement can be performed, but several special considerations are needed. In patients with postpoliomyelitis syndrome, osteoporosis is common because of prolonged lack of muscle action on the bone. Joint contractures must be corrected at the time of surgery to prevent excessive forces on the prosthetic components because these forces might lead to loosening of the prosthesis. Weak muscles must be supported with the appropriate orthoses after surgery. The rehabilitation program is lengthy because it takes an extended period to regain joint motion and muscle function. Continuous passive motion devices and frequent joint ROM must be used to gain joint mobility after surgery. Because the hip joint is difficult to brace, there must be at least fair (grade 3) strength (see Table 13–1) in the hip extensors, abductors, and flexors to provide stability to the hip after surgery. Surgery can be expected to weaken the surrounding muscles, which must be taken into account before total hip arthroplasty is undertaken to prevent chronic dislocation.
The shoulder is important for placing the hand in the desired position for use. The shoulder totally depends on muscle strength for active mobility. In patients who use a wheelchair, weak muscles about the shoulder can be made more functional with the use of mobile arm supports on the wheelchair. These supports allow the patient a greater arc of motion with less muscle strength. Shoulder stability is more important in the ambulatory patient who requires upper extremity aids. A glenohumeral fusion may be helpful if the patient has sufficient strength in the scapulothoracic muscles. When the shoulder is fused, scapulothoracic motion is maintained, allowing use of the extremity for tabletop activities. Glenohumeral fusion does restrict the ability of the patient to position the hand for bathroom hygiene, so it is undesirable to perform the procedure on both shoulders.
Preservation of shoulder strength should be a priority of treatment. Rotator cuff tears are a common problem in postpolio patients. Surgical repair of the torn rotator cuff should be done when possible. In large tears that cannot be repaired, arthroscopic debridement offers significant relief of pain. Shoulder weakness is found in 95% of patients with postpoliomyelitis syndrome and correlates closely with the amount of lower extremity weakness present. Patients with weak legs use their arms to push up from a chair and pull themselves up stairs. They also lean heavily on upper extremity aids while walking. It is therefore important to remove as many unnecessary strains from the shoulders as possible with the use of elevated seats, motorized lift chairs, elevators or motorized stair chair glides, and optimal lower extremity bracing. In minimally ambulatory or nonambulatory patients, an electric wheelchair or motorized scooter should be prescribed to prevent excessive strain on the shoulder muscles caused by propelling a manual wheelchair.
The elbow requires sufficient flexor strength to lift an object against gravity for function. A mobile arm support can maximize the effectiveness of the muscle strength for the patient. Tendon transfers, such as those involving the deltoid and biceps muscles, may also be useful in restoring active flexion.
WRISTS AND HANDS
Opponens paralysis is common in the hand and results in a 50% loss of hand function. A splint used during the acute and recovery phases is useful in preventing an adduction contracture. Opponens function can be restored by tendon transfer. The most common muscle transferred is the flexor digitorum superficialis of the ring finger.
Paralysis of the intrinsic muscles of the hand interferes with function. A lumbrical bar orthosis prevents hyperextension of the metacarpophalangeal joints and allows the long extensors to extend the fingers and open the hand. Surgical capsulodesis to limit metacarpophalangeal joint extension accomplishes the same result.
Paralysis of the finger flexors and extensors can be overcome with the use of a flexor hinge orthosis if wrist extensor function is present. Tendon transfers can provide the same result, allowing the tenodesis effect to provide grasp and pinch functions.
CEREBRAL PALSY (STATIC ENCEPHALOPATHY)
Cerebral palsy is a nonprogressive and nonhereditary disorder of impaired motor function. The onset may be prenatal, perinatal, or postnatal. An exact cause is not always known, but the impairment is sometimes associated with prematurity, perinatal hypoxia, cerebral trauma, or neonatal jaundice. In the United States, more than 500,000 people are affected by cerebral palsy. The degree of neurologic impairment is severe in a third of patients and mild in approximately a sixth.
Because of the diversity of neurologic findings seen in patients with cerebral palsy, a classification system is essential. The disease can be classified by the types of movement disorder and by the patterns of neurologic deficit.
TYPES OF MOVEMENT DISORDER
Three types of disorder are seen.
These are characterized by the presence of clonus and hyperactive deep tendon reflexes. Patients with spastic movement can be helped by orthopedic intervention.
Among the conditions classified as dyskinetic disorders are athetosis, ballismus, chorea, dystonia, and ataxia. For practical purposes, these conditions are grouped together because they are not amenable to surgical correction.
These usually consist of a combination of spasticity and athetosis with total body involvmement.
PATTERNS OF NEUROLOGIC INVOLVEMENT
With single-limb involvement, the disorder is usually spastic in nature. Because monoplegia is rare, it is advisable to test the patient before making the diagnosis. The stress of performing an activity such as running at a fast pace often uncovers spasticity in another limb.
Spasticity affects the upper and lower extremities ipsilaterally. Equinovarus posturing is common in the lower extremity. The upper extremity is usually held with the elbow, wrist, and fingers flexed and the thumb adducted. The major problem interfering with upper extremity function, however, is a loss of proprioception and stereognosis. Surgery for the upper extremity is aimed at making the hand assistive and at improving cosmesis. An arm that is involuntarily held in severe flexion while the patient walks can present a major social disadvantage for the patient.
In paraplegia, neurologic deficits involve only the lower extremities. Because paraplegia is rare in patients with spastic cerebral palsy, the existence of a high spinal cord lesion that could also be responsible for the neurologic findings must be ruled out. Bladder problems coexist with spastic paralysis that affects the lower extremities and is secondary to spinal cord damage.
Spastic diplegia, seen in 50–60% of cerebral palsy patients in the United States, is the most common neurologic pattern. It is characterized by major involvement in both lower extremities with only minor incoordination in the upper extremities. Findings in the lower extremities include marked spasticity, particularly about the hips, hyperactive deep tendon reflexes, and a positive Babinski sign. The hips are commonly held in a position of flexion, adduction, and internal rotation secondary to the spasticity. The knees are in the valgus position and may have excessive external rotation of the tibia. The ankles are held in the equinus position, with a valgus attitude of the feet. Speech and intellectual functions are usually normal or only slightly impaired. Esotropia and visual perception problems are common.
Total Body Involvement
Sometimes referred to as quadriplegia, total body involvement is characterized by impairments affecting all four extremities, the head, and the trunk. Sensory deficits are typical, and speech and swallowing are commonly impaired. The most serious deficit is often the inability to communicate with others. Although mental retardation is found in approximately 45% of patients, intelligence is often masked by communication dysfunction. Ambulation is not usually a goal because the equilibrium reactions of affected patients are severely impaired or absent. Sitting may require braces or adaptive supportive devices. Scoliosis, contractures, and dislocated hips are common orthopedic problems and may interfere with sitting.
Because cerebral palsy in children is discussed elsewhere (see Chapter 11), the following discussion concentrates on the needs of the adult with cerebral palsy.
SPECIAL CONSIDERATIONS IN ADULT PATIENTS
Long-standing deformities may be rigid. Bony deformities are common and may preclude surgery for soft-tissue rebalancing unless concomitant osteotomies are done. In comparison with the young patient, the adult patient has a greater body mass to support and therefore has increased energy demands. Spastic muscles are weak and frequently further compromised by the chronic overuse of muscles to compensate for contractural deformities.
The patient who can sit independently has good balance and may propel a wheelchair. It may be easier to propel the wheelchair backward, using the feet to push. A self-propped sitter may require some external support to remain erect, whereas a propped sitter needs a straight spine and flexible hips to remain erect with support.
Ambulation can be divided into four categories: community ambulation, household ambulation, physiologic ambulation (exercise), and wheelchair ambulation. A patient categorized as a community ambulator is able to maneuver independently and safely around obstacles normally encountered in the community. Orthotics or upper extremity walking aids may be required. A household ambulator is able to walk independently for short distances but requires assistance to negotiate obstacles such as stairs or curbs and requires a wheelchair for long distances. A physiologic ambulator is someone who is capable of walking for short distances with assistance or walks as a means of exercise but finds it impractical to walk for normal activities. The energy requirements for walking determine the category to which a patient belongs and also determine the types of equipment that are recommended. It is unreasonable to expect patients to expend all their energy in merely transporting themselves from one location to another.
TREATMENT OF PATIENTS WITH LOWER EXTREMITY PROBLEMS
An adduction and internal rotation deformity of the hip is sometimes seen during ambulation. Release of the hip adductor tendons (see Figure 13–13) may be needed to correct this tendency.
A crouch gait and lumbar lordosis are evidence of hip flexion deformity. In patients with cerebral palsy, gait studies with dynamic poly-EMG demonstrated dysphasic activity of the iliopsoas, which is the main hip flexor muscle. Gait studies with poly-EMG should be undertaken to evaluate the activity of the iliopsoas and pectineus and to aid in surgical decision making. If release of the iliopsoas is indicated, the tendon is cut distally and allowed to retract proximally to the point where it reattaches to the anterior hip capsule (Figure 13–31). Release of the pectineus muscle is often also necessary.
Correction of a knee flexion deformity in a patient with a crouch gait may be necessary. Attention should first be paid to the hip deformity. Weakness of the gastrocnemius and soleus muscles and inability to maintain the position of the tibia may also contribute to a crouch posture and should be considered prior to performing any knee surgery. Gait electromyograms are useful in determining which muscles are responsible for the abnormal posture. Release of the offending hamstring tendons (see Figure 13–15) or hamstring lengthening may be useful.
Equinus posturing of the ankle is common. If no fixed contracture is present, an AFO controls the position of the foot. If the deformity is the result of an equinus contracture, Achilles tendon lengthening (see Figure 13–16) should be performed to bring the foot to a neutral position. The foot should be held in a short leg walking cast for 6 weeks following surgery. An AFO is then used to maintain the position of the foot and support the tibia during walking.
Equinovarus posturing of the ankle is also common. Although the anterior tibial muscle is the primary varus force in patients with stroke or traumatic brain injuries, it is equally likely that the posterior tibial muscle may be causing equinovarus posturing in patients with cerebral palsy. Therefore, in order to find the cause and make the correct decision concerning surgery, it is important to make dynamic EMG recordings while the patient walks.
If the anterior tibial muscle is overactive, Achilles tendon lengthening should be accompanied by a split anterior tibial tendon transfer (see Figure 13–18). If the posterior tibial muscle is overactive, it is advisable to lengthen the posterior tendon. If the EMG studies show that the posterior tibial muscle is active only during the swing phase of gait, it may be more logical to transfer the posterior tendon through the interosseous membrane to the dorsum of the foot, rather than performing a split anterior tibial tendon transfer. After surgery is performed, a short leg cast that allows weight bearing is worn for 6 weeks, and the leg is then supported with an AFO. If hallux valgus subsequently develops, management consists of correcting the subtalar deformity and realigning the first digital ray.
A pes cavus deformity of the foot is occasionally seen in patients with spasticity of the intrinsic muscles. If the problem is detected early, it can be corrected by plantar fasciotomy and release of the flexor origins from the os calcis. If the problem is detected late and a concomitant bony deformity is present, a wedge osteotomy of the midtarsal bones should be performed.
TREATMENT OF PATIENTS WITH UPPER EXTREMITY PROBLEMS
Function of the upper extremities depends on a variety of factors, including cognition, intact sensation, and the ability to place the hand in space. The amount of spasticity present also affects the ability to control movement of the arm and hand. Surgery can influence hand placement and modify spasticity, but a successful outcome requires the ability to cooperate with postoperative therapy programs. Mental impairment, motion disorders, and poor sensation are relative contraindications to surgery in the functional arm and hand.
The Functional Upper Extremity
In patients with problems involving the functional hand, treatment begins with careful clinical evaluation of motor and sensory deficits. Dynamic EMG is extremely useful in determining which muscles should be lengthened or transferred to improve function. The least severely involved hands exhibit a minor degree of spasticity in the flexor carpi ulnaris and a resulting mild flexion deformity of the wrist. In this case, all that is required to improve hand function and position is surgical lengthening of the flexor carpi ulnaris tendon.
In some patients, release of objects from the hand is a problem. In this case, the synergistic action of the finger extensors and wrist flexors causes difficulty with finger extension when the wrist is extended. This resembles the tenodesis effect seen in paralytic hands, but the mechanism is a dynamic one. Selective lengthening of the overactive finger flexors (see Figure 13–23) improves hand function.
Transfer of a wrist flexor to a wrist extensor should be done with caution. Often a patient flexes the wrist to adjust the dynamic balance between the finger flexors and extensors. Holding the wrist in extension can rob the patient of this important method of compensation.
The thumb-in-palm deformity is treated by proximal release of the thenar muscles (see Figure 13–24 ) and lengthening of the flexor pollicis longus tendon. Distal release of the thenar muscles is not recommended because it may cause a hyperextension deformity of the metacarpophalangeal joint of the thumb.
The Nonfunctional Upper Extremity
Surgery may be indicated in the nonfunctional upper extremity to prevent skin breakdown, to improve hygiene or cosmesis, or to make dressing easier. The problems of shoulder contracture and elbow contracture are discussed in the section on stroke, and the surgical procedures used in their treatment are shown in Figures 13–20 and 13–21. Patients who have a flexed wrist with flexed fingers and a thumb-in-palm deformity should be treated because severe wrist flexion can cause median nerve compression against the proximal edge of the transverse carpal ligament. An arthrodesis of the wrist in neutral position, combined with a superficialis-to-profundus tendon transfer (see Figure 13–22), reliably corrects the wrist deformity and also improves skin care. Management of the thumb deformity consists of lengthening the flexor pollicis longus tendon, fusing the interphalangeal joint, and performing a proximal release of the thenar muscles (see Figure 13–24).
TREATMENT OF PATIENTS WITH TOTAL BODY INVOLVEMENT
Patients with total body involvement are rarely functional ambulators, although they may transfer from one position to another either independently or with assistance. They frequently have a combination of spasticity and motion disorders such as athetosis, and they spend most of their time in a chair. Flexible hips and a straight spine are needed for functional sitting.
Occasionally, knee flexion deformities require distal hamstring release or lengthening to allow for greater flexibility in positioning the patient. Rigid extension contractures of the knee are sometimes seen and interfere with sitting tolerance. Lengthening of the quadriceps tendon (Figure 13–32) allows the knee to flex.
Foot deformities in the spastic patient are extremely common and require treatment to allow shoe wear and to prevent skin breakdown. Sitting balance is improved when the feet can be positioned on the leg support of a wheelchair.
The spine is of major concern in patients with total body involvement because scoliosis is common. Adaptive seating or orthotics are useful in supporting the spine and helping the patient maintain an erect posture while seated. Spinal fusion with instrumentation is indicated for treatment of progressive scoliosis. Obliquity of the pelvis greatly interferes with sitting. When this problem is present, fusion should include the sacrum.
The neuromuscular disorders represent a diverse group of chronic diseases characterized by the progressive degeneration of skeletal musculature, which results in weakness, atrophy, joint contractures, and increasing disability. These disorders are best classified as motor unit diseases because the primary abnormality may involve the motor neuron, the neuromuscular junction, or the muscle fiber. Two broad categories are considered. Myopathies are diseases of the muscle fibers. Neuropathies are disorders in which muscle degeneration is seen secondary to lower motor neuron disease. Most of the neuromuscular disorders are hereditary (Table 13–7), although point mutations may result in spontaneous cases. Early diagnosis is important not only for initiation of appropriate therapy but also for genetic counseling. Treatment programs are aimed at symptomatic and supportive care. Appropriate orthopedic intervention can significantly increase the functional capacity of patients with neuromuscular disorders.
HISTORY AND PHYSICAL EXAMINATION
A careful genetic history is important. The clinical history and physical examination delineates the onset and pattern of muscle involvement. Neuropathies generally present with distal involvement. Muscle fasciculation and spasticity are common, and muscle atrophy is in excess of the weakness. Myopathies usually display weakness of the proximal limb musculature initially. Fasciculations and spasticity are not seen. The weakness is more pronounced than the atrophy. Disorders of neuromuscular transmission, such as myasthenia gravis, present with fatigue and ptosis.
MUSCLE ENZYME STUDIES
Serum levels of muscle enzymes are elevated in myopathies but normal in neuropathies. The enzymes studied include creatine phosphokinase (CPK), lactate dehydrogenase (LDH), aldolase, aspartate aminotransferase (AST, SGOT), and alanine aminotransferase (ALT, SGPT). CPK levels are the most elevated in the Duchenne type of muscular dystrophy and less elevated in the more slowly progressive disease forms. In Duchenne-type muscular dystrophy, the highest enzyme levels are seen at birth and during the first few years of life, before the disease is clinically apparent. As the disease progresses and the muscle mass deteriorates, the enzyme levels decrease.
ELECTROMYOGRAPHY AND NERVE CONDUCTION STUDIES
EMG and nerve conduction studies differentiate between primary muscle diseases and neuropathies (see Table 13–7). EMG is useful in differentiating among muscle diseases, peripheral nerve disorders, and anterior horn cell abnormalities. A myopathic pattern on EMG is characterized by (1) increased frequency, (2) decreased duration, and (3) decreased amplitude of action potentials. In addition, increased insertional activity, short polyphasic potentials, and a retained interference pattern are evident. A neuropathic pattern on EMG is characterized by the opposite constellation of findings: (1) decreased frequency, (2) increased duration, and (3) increased amplitude of action potentials. In addition, frequent fibrillation potentials, a group polyphasic potential, and a decreased interference pattern can be seen. In myasthenia gravis and the myotonic diseases, the patterns on EMG are diagnostic. In myasthenia gravis, the fatigue phenomenon is exhibited. In myotonia, the EMG is characterized by positive waves and trains of potentials that fire at high frequency and then wax and wane until they slowly disappear.
To gain the maximal amount of information from muscle biopsy, the clinician should choose a muscle that has mild to moderate involvement and was not recently traumatized by electrodes during EMG. Muscle biopsy can be used to differentiate myopathy, neuropathy, and inflammatory myopathy. The biopsy, however, cannot be used to determine prognosis. Histochemical staining further distinguishes the congenital forms of myopathy.
Histologically, myopathies are characterized by muscle fiber necrosis, fatty degeneration, proliferation of the connective tissue, and an increased number of nuclei, some of which have migrated from their normal peripheral position to the center of the muscle fiber.
Neuropathies display small, angulated muscle fibers. Bundles of atrophic fibers are intermingled with bundles of normal fibers. There is no increase in the amount of connective tissue.
Biopsy findings in polymyositis include prominent collections of inflammatory cells, edema of the tissues, perivasculitis, and segmental necrosis with a mixed pattern of fiber degeneration and regeneration.
Duchenne-Type Muscular Dystrophy
Duchenne-type muscular dystrophy, which is also called pseudohypertrophic muscular dystrophy, is a progressive disease that affects males. It is inherited in an X-linked recessive manner and has its onset in early childhood. Generally, affected children have a normal birth and developmental history. But by the time they reach 3–5 years of age, sufficient muscle mass has been lost to impair function.
Early signs of disease include pseudohypertrophy of the calf, which is the result of the increase in connective tissue; planovalgus deformity of the feet, which is secondary to heel cord contracture; and proximal muscle weakness. Muscle weakness in the hips may be exhibited by the Gower sign, in which the patient uses the arms to support the trunk while attempting to rise from the floor. Other signs are hesitance when climbing stairs, acceleration during the final stage of sitting, and shoulder weakness.
Weakness and contractures prevent independent ambulation in approximately 45% of patients by 9 years of age and in the remainder by 12 years of age. It is common for patients to have difficulty first in rising from the floor, next in ascending the stairs, and then in walking. Cardiac involvement is seen in 80% of patients. Findings generally include posterobasal fibrosis of the ventricle and electrocardiographic changes. In patients with a decreased level of activity, clinical evidence of cardiomyopathy may not be obvious. Pulmonary problems are common in the advanced stages of the disease and are found during periodic evaluations of pulmonary function. Mental retardation, noted in 30–50% of patients, is present from birth and not progressive.
Efforts are made to keep patients ambulating for as many years as possible to prevent the complications of obesity, osteoporosis, and scoliosis. The hip flexors, tensor fasciae latae, and triceps surae develop ambulation-limiting contractures. With progressive weakness and contractures, the base of support decreases and the patient cannot use normal mechanisms to maintain upright balance. The patient walks with a wide-based gait, hips flexed and abducted, knees flexed, and the feet in equinus and varus position. Lumbar lordosis becomes exaggerated to compensate for the hip flexion contractures and weak hip extensor musculature.
Equinus contractures of the Achilles tendon occur early and are caused by the muscle imbalance between the calf and pretibial muscles. Initially, this problem can be managed by heel cord stretching exercises and night splints. A KAFO may be needed to control foot position and substitute for weak quadriceps muscles. Stretching exercises and pronation can be employed to treat early hip flexion contractures.
Surgical intervention is directed toward the release of ambulation-limiting contractures. Early postoperative mobilization is important to prevent further muscle weakness. Anesthetic risks are increased in these patients because of their limited pulmonary reserve and because the incidence of malignant hyperthermia is higher than normal in patients with muscle disease.
The triceps surae and tibialis posterior are the strongest muscles in the lower extremity of the patient with muscular dystrophy. These muscles are responsible for equinus and varus deformities. Management that consists of releasing the contracted tensor fasciae latae, lengthening the Achilles tendon, and transferring the tibialis posterior muscle anteriorly is indicated and prolongs walking for approximately 3 years. Postoperative bracing is required.
Scoliosis is common in nonambulatory patients confined to a wheelchair. Adaptive seating devices that hold the pelvis level and the spine erect are useful in preventing deformity. Alternatively, a rigid plastic spinal torso orthosis may be used for support. When external support is not effective, scoliosis develops rapidly. Spinal fusion is occasionally indicated. Blood loss during surgery is high, and the incidence of pseudarthrosis is increased. Postoperative immobilization is to be avoided; therefore, segmental spinal stabilization is often the preferred technique of internal stabilization.
Fractures in patients with myopathies occur secondary to osteoporosis from the inactivity and the loss of muscle tension. No abnormalities of bone mineralization are present. The incidence of fracture increases with the severity of the disease. Most fractures are metaphyseal in location, show little displacement, cause minimal pain, and heal in the expected time without complication.
Spinal Muscular Atrophy
Spinal muscular atrophy is a neuropathic disorder in which fewer anterior horn cells are present in the spinal cord congenitally. The severe infantile form of the disease is called Werdnig-Hoffmann paralysis. The disorder is inherited in an autosomal-recessive pattern.
Approximately 20% of patients with spinal muscular atrophy are ambulatory, and 1% are totally dependent. Fractures are common in these patients and occur secondary to decreased mobility and function.
The goal of orthopedic intervention is to prevent collapse of the spine and contractures. Orthotic support is often needed to stabilize the spine. In the nonambulatory patient, adaptive seating devices or orthotics may be used. If collapse of the spine occurs, spinal fusion is indicated.
Charcot-Marie-Tooth disease is the most common of the hereditary degenerative myopathies. It is generally inherited in an autosomal-dominant pattern. EMG studies show a neuropathic pattern, and the nerve conduction velocity of the involved nerves is markedly decreased. Muscle enzyme levels are normal. Clinical onset of the disease is between 5 and 15 years of age.
The peroneal muscles are affected early in the course of the disease. For this reason, Charcot-Marie-Tooth disease is sometimes referred to as progressive peroneal muscular atrophy. The intrinsic muscles of the feet and hands are affected later. Patients usually present with progressive clawtoe and cavus deformities of the feet. In the skeletally immature patient, release of the plantar fascia is done to correct the cavus deformity. This is often combined with transfer of the extensor digitorum longus tendon to the neck of the metatarsal and fusion of the proximal interphalangeal joints of the toes to correct the clawtoe deformities. If the tibialis posterior muscle is active during swing phase, it can be transferred through the interosseous membrane to the lateral cuneiform bone. Triple arthrodesis is often necessary in the adult to correct the deformity.
The intrinsic minus hand deformity causes difficulty in grasping objects. An orthosis with a lumbrical bar to hold the metacarpophalangeal joints flexed improves hand use. A capsulodesis of the volar portion of the metacarpophalangeal joints accomplishes the same objective. To restore active intrinsic muscle function in the hand, the flexor digitorum superficialis tendon of the ring finger can be divided into four slips and transferred through the lumbrical passages to the proximal phalanx.
Parkinson disease (PD) is a progressive neurodegenerative disorder associated with a loss of dopaminergic nigrostriatal neurons. PD is recognized as one of the most common neurological disorders, affecting approximately 1% of individuals older than 60 years. The incidence and prevalence of PD increase with age. The average age of onset is approximately 60 years. Onset in persons younger than 40 years is relatively uncommon.
The major neuropathologic findings in PD are a loss of pigmented dopaminergic neurons in the substantia nigra and the presence of Lewy bodies. The loss of dopaminergic neurons occurs most prominently in the ventral lateral substantia nigra. Approximately 60–80% of dopaminergic neurons are lost before clinical symptoms of PD emerge.
Onset of PD is typically asymmetric, with the most common initial finding being an asymmetric resting tremor in an upper extremity. Approximately 20% of patients first experience clumsiness in one hand. Over time, patients notice symptoms related to progressive bradykinesia, rigidity, and gait difficulty. The initial symptoms of PD may be nonspecific and include fatigue and depression.
The three cardinal signs of PD are resting tremor, rigidity, and bradykinesia. Of these cardinal features, two of three are required to make the clinical diagnosis. Postural instability is the fourth cardinal sign, but it emerges late in the disease, usually after 8 years or more.
The goal of medical management of PD is to provide control of signs and symptoms for as long as possible while minimizing adverse effects. Medications (eg, levodopa) usually provide good symptomatic control for 4–6 years. After this, disability progresses despite best medical management, and many patients develop long-term motor complications including fluctuations and dyskinesia. Additional causes of disability in late disease include postural instability (balance difficulty) and dementia.
When medical management is exhausted, neurosurgical interventions include deep brain stimulation, thalamotomy, pallidotomy, and fetal cell transplantation.
Treatment of orthopedic problems in patients with PD can be problematic and include failure of fixation or prosthetic dislocation. Despite successful pain relief, the functional results of total joint arthroplasty in patients with Parkinson disease are poor, especially in patients older than 65 years, and complications are more frequent. Success in terms of pain relief and no further need for intervention can be obtained with appropriate medical management of the PD after orthopedic intervention.
More than 2 million people sustain burns of sufficient severity each year in the United States to require medical attention. Of these, 50,000 individuals remain hospitalized for more than 2 months, attesting to the serious nature of their injuries.
Thermal burns affect the skin most directly but can also involve the underlying muscles, tendons, joints, and bones. Scar contractures cause the greatest limitation to later function and the greatest deformity. Rehabilitation efforts ideally should begin when the patient first enters the hospital, immediately following acute resuscitation and continuing through the reconstruction process.
Burn wounds are traditionally classified as first, second, or third degree, depending on the depth of the damage. Currently, it is thought to be more useful to simply divide burns into two categories: partial thickness (involving part of the dermis) and full thickness (involving the entire dermis).
First-degree burns damage only the epidermis. They cause erythema, minor edema, and pain. The skin surface remains intact, and healing occurs uneventfully in 5–10 days, without residual scar formation.
Second-degree burns involve the epidermis and a variable amount of the underlying corium. The depth of damage to the corium determines the outcome of healing. In the more superficial second-degree burns, blister formation is prominent and occurs secondary to the osmotic gradient formed by particles in the vesicle fluid. Superficial second-degree burns heal in 10–14 days, with minimal scarring. Deep dermal burns are characterized by either a reddish appearance or by the presence of a white tissue that is barely perceptible and adheres to the underlying viable dermis. These wounds may advance to a full-thickness loss if infection occurs. They heal with a fragile epithelial covering. Healing occurs over 25–30 days, and dense scar formation is common.
Third-degree burns are full-thickness injuries that damage the epidermis and the entire corium. Because of the loss of pain receptors, which are normally found within the corium, pain is absent. The burns have a thick leathery surface of dead tissue.
TECHNIQUES FOR MAINTAINING FUNCTIONAL POSITION
Burn scars contract and become rigid, so it is critical to maintain the head, trunk, and extremities in a functional position. Contractures, if allowed to form, severely limit later function. The location of the burns determines which techniques are useful in preventing deformity.
To prevent deformities of the neck and jaw in patients with burns of the neck or upper torso, molded splints should be applied early to maintain the head and neck in a neutral position or in slight extension. Patients with burns in the shoulder region are at risk for contractures characterized by a protracted scapula with an adducted arm. Placing a roll between the scapulae and providing support with a firm mattress help prevent scapula protraction. To keep the arms abducted 75–80 degrees and the shoulder flexed 20–30 degrees, axillary foam pads are used and can be held in position with a figure-of-8 wrapping, which maintain the glenohumeral joint in a functional position. Untreated contractures not only limit limb motion but also can result in joint subluxation from extremes in positioning.
When the burns involve the torso, the goal is to maintain a straight spine in the face of contracting scar tissue. Burns involving only one side of the trunk sometimes result in scoliosis. This should be corrected by scar excision and splinting. If left uncorrected, the scoliosis becomes structural, with resultant bony changes. Burns in the groin area tend to cause flexion and adduction contractures of the hip. To prevent this, the patient should be positioned with the hips extended and in 15–20 degrees of abduction. If the patient is lying on a soft mattress, mild flexion deformities of the hips may be masked. Daily pronation is useful in maintaining the extension range of the hips.
Regardless of the location of burn wounds on the extremities, the knees and elbows tend to develop flexion contractures. Custom-molded thermoplastic splints can be applied over dressings or skin grafts to maintain the extremities in extension. The splints should be removable to allow for daily wound care. Burns in the ankle area result in equinus contractures with inversion of the foot. Splints can be used here also to maintain the foot in a neutral position, but care must be taken to ensure the splint is holding the foot adequately and not merely obscuring a deformity. Custom-molded splints applied to the anterior and posterior surfaces in a clamshell fashion are more effective in maintaining the desired position. They also assist in the control of edema and can be removed for wound care and motion exercises. Burns on the dorsum of the foot cause hyperextension deformities of the toes. Early grafting and toe traction are useful.
Burns of the hands present special problems. Scar contracture results in a flexion deformity of the wrist and a clawhand position similar to that seen with loss of the intrinsic musculature. The hand should be splinted with the wrist in neutral or in a slightly extended position. The metacarpophalangeal joints should be flexed 60–75 degrees and the interphalangeal joints extended. The thumb should be held with the metacarpal in abduction and flexion, the metacarpophalangeal joint in mild flexion, and the interphalangeal joint in the extended position.
SKELETAL TRACTION AND EXTERNAL SUSPENSION
In patients with circumferential burns on an extremity, the use of skeletal traction or external fixators and suspension is efficacious and has several advantages. It permits access to all surfaces, elevates the limb to decrease edema, and maintains the extremity in the desired position while allowing joint motion. Traction can be used to correct contractures. In addition, traction still allows for daily hydrotherapy. Generally, traction is only employed for a 2-week period because longer use may result in a pin tract infection with formation of sequestra.
Special splints are fabricated for use in the hand. The traction frame is secured proximally with a pin inserted through the distal radius. Pins are also placed through the distal phalanges of the fingers and thumb by drilling through the nail bed from the dorsal to the volar surface. Traction is applied to the fingers in the desired direction by attaching rubber bands from the distal pins to the outrigger frame. The frame can be modified for use in the foot to apply traction to the toes. In this case, the traction frame is secured proximally with a pin inserted through the calcaneus.
Consistent pressure of 25 torr applied evenly aids in the prevention of hypertrophic scar formation and contracture. Elastic wraps applied over splints are used early after the injury and following grafting because they can be adjusted for changes in the amount of edema present. Later, when the amount of swelling shows little fluctuation, custom elastic garments are employed. Pressure must be continued for as long as the scar tissue is biologically active. When the skin is soft and flat and returns to normal color, the pressure can be discontinued. Pressure dressings should be employed for a minimum of 6 months and may be necessary for as long as a year. The daily application of lanolin relieves the dryness of grafted skin or substitutes for the loss of sebaceous gland secretions in deep burns.
Early motion is desirable for burned and uninvolved extremities. Splints should be removed frequently to allow for ROM exercises. If the patient is being treated with skeletal traction, motion exercises can be performed on the extremities. If the patient is receiving hydrotherapy for the burn wounds, the motion exercises are facilitated with the extremities supported in the fluid environment.
Patients with burns of the lower extremities can begin to stand or walk before skin grafts are performed, provided the legs are wrapped with elastic supports to control edema. Ambulation should be resumed after skin grafting as soon as the grafts are stable. Early mobilization not only preserves joint motion but also decreases the incidence of sequelae such as osteoporosis, physiologic deconditioning, muscle atrophy, and heterotopic ossification.
TREATMENT OF SPECIAL PROBLEMS
If fractures occurred at the time of the burn, they can be treated with the use of skeletal traction or external supports such as splints. Diagnosis may be delayed if the fractures do not result in any obvious deformity. If fractures occur secondary to disuse osteoporosis, they are usually minimally displaced and heal uneventfully. Pathologic fractures are less common with early mobilization.
Osteomyelitis is not a common complication, despite the high incidence of sepsis associated with burns. Prolonged exposure of bone sometimes results in the formation of a tangential sequestrum in the devitalized cortex. Exposed bone surfaces can be drilled to promote the formation of a granulation tissue bed for skin grafting without an increased risk of infection. The prolonged use of pins for skeletal traction causes infection in 5% of patients who require traction. The use of threaded traction pins minimizes the motion of the pin in the bone. Pins should be removed as soon as possible.
Children and adolescents with exposed joint surfaces may retain some function after healing, but adults often develop joint ankylosis or deformities that require arthrodesis at a later date. To maintain the joint in the desired position, traction can be used. The joint should be irrigated with hypochlorite solution daily and debrided as necessary. The exposed bone surfaces can be drilled to promote the formation of granulation tissue. When the bed of tissue covers the joint, skin grafting is performed.
Periarticular bone formation is seen in 2–3% of patients with severe burns. Although the cause is unknown, predisposing factors include full-thickness burns involving more than 30% of the body surface, prolonged immobilization, and superimposed trauma. The location of the heterotopic bone is not determined by the distribution of the burns. Ossification can occur in any of the major joints. In adults, the elbow is the joint most frequently affected; the hip is rarely affected. In children, the hip and elbow are common sites; the shoulder is an uncommon site.
Heterotopic bone can continue to form as long as open granulating wounds are present. If joint ankylosis does not occur, the ossification gradually diminishes after the burns heal. In children, it may disappear completely. If joint ankylosis occurs, surgical resection is indicated and usually restores a functional arc of motion, particularly when the heterotopic bone is in a single plane and the articular surface is not violated. When the heterotopic bone is present in multiple planes, the problem may recur after resection. Early mobilization of patients with burns decreases the incidence and severity of heterotopic ossification.