Orthopedic Emergencies: Expert Management for the Emergency Physician 1st Ed.

Chapter 6. Spine emergencies

Kelley Banagan

Orthopedic Emergencies, ed. Michael C. Bond, Andrew D. Perron, and Michael K. Abraham. Published by Cambridge University Press. © Cambridge University Press 2013.

Acute spine injuries: Cervical, thoracic, and lumbar spine fractures and the spine-injured patient

Key facts

·        The initial evaluation of spine injuries in a trauma patient is of obvious importance, as a missed injury can cause permanent and devastating neurologic injuries

·        Spinal cord and spinal column injuries are typically seen in two age groups and with two different mechanisms. High-energy mechanisms in the younger patient population, and lower-energy mechanisms in older patients with ankylosed spines, or those at risk of fragility fractures

·        Closed head injuries and facial trauma should prompt a work-up for a cervical spine injury, as it implies that the cervical spine was also subjected to a great deal of force

·        If a single spinal fracture is identified, potential spinal injuries at other levels should be evaluated

Evaluation and management

·        Protocols and systems to immobilize patients at the scene, protect the spine, and provide safe extrication and transport to the emergency department have increased survival in the spine-injured patient, and reduced the number of neurologic injuries

·        Poor immobilization and handling of patients have been shown to result in further neurologic injury after the initial accident or insult

·        Patient immobilization during transport should consist of a rigid cervical collar, lateral supports, and securing the patient to a backboard with tape and body supports

·        Young children are the exception, owing to the fact that their heads are disproportionately larger than their bodies. They should not be positioned flat on a backboard as this can cause anterior translation and flexion of a cervical injury. In order to accommodate this anatomic variation the backboard needs to be equipped with an occipital recess or a mattress placed beneath the torso and backboard

·        Patients with ankylosing spondylitis also require special attention be paid to positioning during transport. These patients often have a fixed kyphotic deformity of the spine. This posture should be respected and maintained during transport. The patient’s head may need to be supported with several pillows

·        Prolonged unnecessary immobilization can lead to increased morbidity in the form of pressure sores and other ailments; patients should be removed from the backboard in a timely fashion, and cervical collars should be removed as soon as a cervical injury is ruled out

Emergency evaluation: ABCDE

·        Airway: The cervical spine must be maintained in a stable position while managing the airway in a trauma patient. In-line immobilization with the cervical spine in a neutral position during direct laryngoscopy and orotracheal intubation is the preferred method

PEARL: Manual in-line traction has fallen out of favor because of the potential of distracting a cervical spine injury, especially one at the occipitocervical junction. In-line immobilization is preferred, and should not consist of any traction being applied to the cervical spine.

·        Breathing: Patients who experience a spinal cord injury at or above C3 typically require emergent intubation at the scene secondary to respiratory distress. Patients with signs of impeding respiratory failure should be pre-emptively intubated

·        Circulation: Hypotension, if present, should be assumed to be a result of hemorrhagic shock, and a search for the source of bleeding should follow. Initial treatment involves aggressive fluid resuscitation and vasopressors, as needed

PEARL: Seat-belted patients who present with a thoracolumbar flexion distraction injury should be evaluated for intra-abdominal trauma, including a blunt aortic injury.

·        Neurogenic shock: Classically presents with hypotension in the setting of bradycardia. It occurs in roughly 20% of patients with cervical spine trauma, and is the result of disruption of the sympathetic tone of the peripheral vasculature and the heart

PEARL: Neurogenic shock is classically seen in patients with spinal cord injury above T4.

·        Disability and exposure: A log roll should be performed during the secondary survey. Tenderness, swelling, bruising or a step-off deformity may be signs of a spine injury. A digital rectal exam and assessment of the patients rectal tone is an essential part of the neurologic assessment and the general trauma evaluation

PEARL: Lower-extremity injuries such as calcaneal, pilon, or tibial plateau fractures that result from axial loading should prompt the physician to evaluate the spine for a thoracolumbar burst fracture.

Neurologic evaluation (Tables 6.16.26.3)

·        In the acute setting the neurologic assessment is performed in accordance with the international standards for the Neurologic Classification of Spinal Cord Injury, formerly the ASIA (American Spinal Injury Association) standards

·        Motor examination: Measures the strength of five upper and five lower-extremity myotomes on a grading scale of 0–5, established by the Medical Research Council

·        Sensory examination: Performed by evaluating light touch and pinprick sensation in 28 dermatomes. Sensation is either absent, impaired or normal and scored 0, 1, 2 respectively

·        Reflexes: in patients with spinal cord injuries reflexes are usually absent initially and the limbs are flaccid. Reflexes will become hyperreflexic later in the course of spinal cord injury

·        A Babinski response, when pathologic, is associated with upper motor neuron dysfunction. The reflex is elicited by stroking the lateral plantar surface of the foot with a semi-sharp object. A pathologic response will be noted by extension of the great toe with flexion and spreading of the lateral toes

·        A bulbocavernosus reflex is performed by tugging on the bladder catheter or stimulating the glans or clitoris and evaluating whether reflex anal contraction occurs

·        Spinal shock: A temporary state of the acutely injured spinal cord marked by loss of reflex function below the level of the injury. This typically lasts from 24 to 48 hours, and the end is marked by the return of reflexes, including the bulbocavernosus reflex. Technically speaking the diagnosis of a complete spinal injury can not be made until spinal shock resolves

PEARL: If light touch or pinprick sensation is present in any form at S4–5, or if any anal sensation or contraction is present, the patient has an incomplete spinal cord injury.

·        Sensory level: The most distal level with normal sensation to pinprick and light touch

·        Motor level: The most distal level with intact innervation; below this level there are motor deficits

PEARL: The most distal muscle to have grade-3 strength or higher is considered to be fully innervated because of muscle polyinnervation.

Table 6.1 Universal terminology of a spinal cord injury: ASIA Impairment Scale (AIS).


AIS level

Description

A

No motor or sensory function in the lowest sacral segments

B

Sensory sparing in the lowest sacral segments with no motor function

C

Preserved motor function below the neurologic level, with the majority of muscle groups a grade 2 or less

D

As above but with a muscle grade 3 or more

E

Normal motor and sensory function


ASIA impairment scale (AIS): The most widely accepted system for categorizing spinal cord injury patients.

Table 6.2 Muscle strength scoring system.


Grade

Description

5

Muscle contracts normally against full resistance

4

Muscle strength is reduced, but muscle contraction can still move joint across resistance

3

Muscle strength is reduced so that the joint can only be moved against gravity with the examiner’s resistance removed

2

Muscle can move only if the resistance of gravity is removed

1

Only a trace or flicker of movement is seen or felt in the muscle, or fasiculations are observed in the muscle

0

No movement is observed


Table 6.3 Vertebral level and muscle-group controlled.


Vertebral level

Muscle-group controlled

C5

Elbow flexion

C6

Wrist extension

C7

Elbow extension

C8

Long-finger flexion

T1

Finger abductors

L2

Hip flexion

L3

Knee extension

L4

Ankle dorsiflexion

L5

Great- toe extension

S1

Ankle plantar flexion, voluntary anal contraction: present or absent


Initial radiographic evaluation in the spine trauma patient

·        The NEXUS and Canadian C-spine rules are utilized to help the practitioner exclude a C-spine injury without the use of radiographs

·        Asymptomatic patients with the following criteria do not require radiographs:

o   Fully awake, alert and co-operative

o   Involved in a low-energy trauma

o   Neurologically intact

o   No mid-line tenderness

o   Can actively rotate his/her head 45°

o   No distracting injuries

PEARL: Patients with neck pain, tenderness to palpation, and obtunded patients require radiographic evaluation. Patients with distracting injuries should be placed on spine precautions until their other injuries are addressed.

·        At most institutions CT has replaced conventional radiographs as the imaging modality of choice for evaluating potential spine injuries

·        MRI is the study of choice for evaluating ligamentous injuries, neural element trauma and compression, and disc herniations

PEARL: Not all abnormal findings on MRI are clinically significant; MRI has the tendency to “over-read” injury to the posterior ligamentous structures in the cervical and thoracolumbar spine.

·        Both CT and MRI may be needed to clear the cervical spine in an obtunded patient

Special patient population: Ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis (DISH)

·        Recognizing patients with ankylosing spondylitis and DISH is of paramount importance when evaluating for a potential spine injury

·        These patients can suffer fractures and devastating neurologic injuries as a result of even low-energy trauma

·        This patient population can experience rapid neurologic deterioration if their fracture is not identified or if treatment of their fracture is delayed

·        Typical guidelines for determination of spinal stability do not apply to this patient population, and deeming a fracture stable because there is no displacement is a grave error

PEARL: In patients with ankylosing spondylitis or DISH who present with neck or back pain the assumption should be made that they have suffered a fracture. Advanced imaging such as a CT or MRI is mandatory.

Emergency management of the spine-injured patient

·        If an injury is identified, the spine must be protected until definitive management is provided (e.g., rigid cervical orthosis for patients with a cervical spine fracture and maintenance of spine precautions)

·        If a patient has an occipitocervical dissociation, immediate application of a halo is recommended given the highly unstable nature of the injury

·        The administration of high-dose steroids in patients with an acute spinal cord injury is controversial and is not the standard of care

·        Management of blood pressure has been recognized as a neuroprotective strategy, and protocols that aim to keep mean arterial blood pressure above 85 to 90 mm Hg for 5–7 days with aggressive volume resuscitation and vasopressors have shown improved neurologic outcomes

PEARL: Hypotension should be avoided in the patient with an acute spinal cord injury.

Cauda equina syndrome

Key facts

·        Cauda equina syndrome is most often caused by a central disc herniation

·        Usually presents as perineal sensory loss with urologic dysfunction in the setting of back pain and bilateral sciatica

·        Younger patients are typically affected

·        Emergency decompression is typically regarded as the treatment of choice

Symptoms

·        Urinary retention followed by overflow incontinence, that is generally painless

·        Decreased anal sphincter tone or fecal incontinence

·        Saddle anesthesia, including the inability to feel urethral or vaginal sensation

·        Bilateral lower-extremity weakness or numbness

·        Progressive neurologic deficit

Physical examination findings

·        Patients may have back pain, spasm of the paraspinal musculature, and sciatica-type symptoms

·        Perineal numbness or decreased sensation to pinprick

·        Laxity of bladder or anal sphincter, or decreased rectal tone

·        Motor weakness on manual motor testing of major muscle groups

Treatment

·        Patients should undergo emergent MRI if there is suspicion of cauda equina syndrome

·        A foley catheter should be placed to avoid bladder injury from overdistension. A post-void residual or a bladder scan may aid in the diagnosis

·        Consult with the neurosurgical or orthopedic spine service as soon as the diagnosis is suspected

Spinal epidural abscess (SEA)

Key facts

·        Spinal epidural abscess (SEA) is a rare condition, but suspicion should be raised in high-risk patient populations

·        Prompt diagnosis and treatment improve prognosis and minimize neurologic complications

·        Antibiotic therapy and operative intervention is the treatment of choice, although medical management alone is warranted and successful in some cases

Incidence and microbiology

·        SEA accounts for 7% of all spinal infections

·        There has been an increase in the frequency of SEA secondary to:

o   Aging population

o   Increased prevalence of co-morbidities such as diabetes mellitus

o   Increased number of invasive spinal procedures

o   Intravenous drug use

·        Most infections occur in the thoracic spine, followed by the lumbar spine

·        SEAs often involve several contiguous vertebral levels, and generally arise as a result of adjacent vertebral discitis or osteomyelitis

·        Hematogenous spread is the most common route of infection

·        Staphylococcus aureus is the most common organism cultured

Risk factors for spinal epidural abscess

·        Diabetes

·        Intravenous drug abuse

·        Bacteremia

·        Alcoholism

·        Trauma

·        Immune suppression

·        HIV infection

·        Chronic steroid use

·        Chronic renal insufficiency

·        Malignancy

·        Indwelling central venous catheters

·        Previous spinal procedures

Clinical presentation and diagnosis

·        Localized back pain, fever, and neurologic deficits are the most common presenting symptoms

·        Direct compression of the neural elements by the abscess can cause neurologic deficits

·        Lab studies include:

o   WBC

o   ESR

o   CRP

o   Blood cultures

o   Urinalysis

PEARL: Plain radiographs and CT scan may be unremarkable unless there is also an ongoing vertebral discitis or osteomyelitis.

PEARL: MRI with gadolinium is the most sensitive and specific test for evaluating and detecting an epidural abscess. If the patient is unable to receive an MRI because of contraindications a CT myelogram should be arranged emergently.

PEARL: Empiric antibiotics should be witheld until a tissue sample/culture can be obtained.

Treatment

·        Prompt diagnosis and treatment is essential to prevent neurologic deterioration and maximize recovery

·        Once diagnosed a consultation to the neurosurgical or orthopedic spine service should be made so that, if warranted, operative intervention can be planned. This usually consists of surgical decompression of the affected levels, followed by targeted long-term antibiotic therapy

·        The primary goals of treatment are eradication of infection, preservation or improvement of neurologic function, relief of pain, and maintaining spine stability

Vertebral compression fractures

Key facts

·        The most common site for osteoporotic compression fractures is the spine

·        A quarter of patients with vertebral compression fractures become sufficiently symptomatic to seek medical attention

·        Pain is usually localized to the fracture level

·        Neurologic symptoms are rare

·        Patients with compression fractures need treatment for their osteoporosis

·        Non-surgical and surgical treatment options exist, and both are effective

Clinical evaluation and imaging

·        A comprehensive history and physical is essential, because these patients often have many co-morbidities

·        There is usually pain with palpation at the fracture site

·        Pain is usually mechanical in nature (e.g., worse with load-bearing positions)

·        Lab work should include CBC, BMP, and ESR, as well as serum and urine electrophoresis

PEARL: Underlying infectious or malignant causes for the fracture should be ruled out.

·        Plain radiographs are the initial study of choice for compression fractures (Figures 6.1 and 6.2)

PEARL: A vertebral compression fracture is defined as radiographic loss of vertebral body height of 20% or more.

·        MRI may be useful to determine whether the fracture is acute or chronic, based on the presence of bony edema



Figure 6.1 A T12 compression fracture. (Image courtesy of Michael C. Bond, MD.)



Figure 6.2 An L1 compression fracture. (Image courtesy of Michael C. Bond, MD.)

Treatment

·        Most compression fractures are successfully managed with rest, activity modification, analgesics and bracing. Two-thirds of patients respond to non-operative care

PEARL: Braces are used to reduce pain by decreasing load on the fractured vertebra, reducing movement through the fracture site, and decreasing muscle spasm.

·        Overall bone health in patients with compression fractures should be evaluated. In the long term this may require the assistance of a rheumatologist or endocrinologist

·        Pharmacotherapy for osteoporosis can reduce fracture incidence by 50%

·        Progressive loss of vertebral body height and progressive kyphosis may necessitate operative intervention

Lumbar disc herniation

Key facts

·        Peak incidence is in the fourth and fifth decades of life

·        Only 4–6% of lumbar disc herniations become symptomatic, and only 2–4% are surgical candidates

·        Distal lumbar levels are most commonly affected, L5/S1, L4/L5

·        Within 3 months of symptom onset, 90% of patients will experience improvement without surgical intervention

Clinical presentation and physical examination

·        Patients typically present with back and leg pain, with or without an inciting event

·        Leg pain will typically follow the dermatomal pattern of the nerve root that is affected by the herniation

PEARL: Presence of sciatica is the most sensitive and specific finding for lumbar disc herniation.

·        Patients may present with the hip and knee of the involved extremity flexed and externally rotated in order to take tension off the involved nerve root

·        A positive straight leg raise test results from increased tension on the nerve root

PEARL: A positive contralateral straight leg raise has a higher specificity than a positive ipsilateral straight leg raise.

·        The level of the herniation will determine the nerve root affected and the resultant radicular symptoms; sensory, motor or reflex deficits may result

·        The ability to perform a thorough and accurate neurologic evaluation is essential in determining normal from abnormal and assessing whether the findings are attributable to a disc herniation

Treatment

·        Surgery is rarely indicated at the time of symptom onset

PEARL: Absolute indications for surgery include cauda equina syndrome or a progressive neurologic deficit.

·        Conservative treatment consists of:

o   Physical therapy

o   NSAIDs

o   Muscle relaxants

o   Epidural steroid injections

o   Oral steroids

o   Acupuncture

o   Manipulation

o   Traction

References

Hahne AJ, Ford JJ, McMeeken JM. Conservative management of lumbar disc herniation with associated radiculopathy: a systematic review. Spine. 2010;15;35(11):E488–504.

Hussain SA, Gullan RW, Chitnavis BP. Cauda equina syndrome: outcome and implications for management. Br J Neurosurg. 2003;17(2):164–7.

Jacobs WCH, van Tulder M, Arts M, et al. Surgery versus conservative management of sciatica due to a lumbar herniated disc: a systematic review. Eur Spine J. 2011;20(4):513–22.

Longo UG, Loppini M, Denaro L, Maffulli N, Denaro V. Conservative management of patients with an osteoporotic vertebral fracture: a review of the literature. J Bone Joint Surg Br. 2012;94(2):152–7.

McGuire R. Case study: AAOS clinical practice guideline: the treatment of symptomatic osteoporotic spinal compression fractures. J Am Acad Orthop Surg. 2011;19:183–4.

Pradilla G, Nagahama Y, Spivak AM, Bydon A, Rigamonti D. Spinal epidural abscess: current diagnosis and management. Curr Infect Dis Rep. 2010;12(6):484–91.

Rousing R, Hansen KL, Andersen MO, et al. Twelve-month follow-up in forty-nine patients with acute/semiacute osteoporotic vertebral fractures treated conservatively or with percutaneous vertebroplasty: a clinical randomized study. Spine. 2010;35(5):478–82.

Schouten R, Albert T, Kwon BK. The spine-injured patient: initial assessment and emergency treatment. J Am Acad Orthop Surg. 2012;20(6):336–46.