Current Diagnosis & Treatment of Pain, 1st Edition

13. Back Pain

Edgar Ross MD

Back pain is the most common cause of chronic pain in the United States, yet the most effective treatment of low back pain remains elusive. There is no general consensus on best practices for either diagnosis or treatment of back pain. Because of the high incidence in the work force, disability from back pain is very high and costly. Because of the lack of consensus, the cost of diagnosis and treatment remain very high. The high costs of back pain come not just from the pain but also from the disability secondary to the pain, needless diagnostic tests, and ineffective treatment.

Most of the diagnostic testing that is ordered is not needed. Even the most sophisticated diagnostic testing often cannot objectively validate most of the spinal pain that is reported by patients. Numerous guidelines have been published that attempt to clarify this problem. For example, the nationally recognized guidelines published by the Agency for Healthcare Research and Quality can assist clinicians in deciding which diagnostic tests are appropriate and which treatment approaches are effective. Diagnosing and treating low back pain efficiently, avoiding ineffective procedures, and minimizing the harmful effects of a sedentary lifestyle can have a substantial impact on patient suffering, lost income, disability, and health care costs.

Deyo RA. Low back pain. N Engl J Med. 2001;344:363

Susman J. The care of low back problems: less is more. Am Fam Physician. 2002;65:2217

Van Tulder M et al. Low back pain (chronic). Clin Evid. 2004; 12:1659

Essential Criteria

  • Most spinal pain is self-limited.
  • A definitive diagnosis cannot be made in upward of 85% of patients, primarily because of the multiple etiologies of back pain and nonspecific nature of diagnostic tests.
  • Low back pain accounts for 40 to 50% of patient visits to pain clinics.
  • Back pain can be categorized as acute (lasting < 6 weeks), subacute (lasting 6 to 12 weeks), or chronic (lasting 12 weeks or longer).
  • Treatment usually consists of appropriate medications for both the neuropathic and nociceptive complaints.

General Considerations

Incidence

Back pain is the second leading reason for physician office visits in the United States today. The prevalence of spinal pain in the United States has been reported as up to 37%, and the peak incidence is found between 45 to 60 years of age. This incidence translates into the fact that 80% of all Americans will seek care at some point in their lives for acute back pain. Notably the age range of 45 to 60 is usually the most productive time period for most workers. This observation is most likely the reason that back pain is responsible for more than one-third of the total disability payments in the United States. The indirect costs of lost earnings are even higher.

Natural History of Back Pain

Table 13-1 presents the duration of symptoms and the prognosis for acute, subacute, and chronic pain. In general, treatment in the good prognosis groups should be supportive with avoidance of interventional therapies (such as surgical procedures), which could carry more risk than benefit. On the other hand, patients who are not improving as expected should be reexamined, and further diagnostic testing performed to rule out potentially serious occult conditions. With persistent pain, referrals to chronic pain programs should be made promptly. This proactive approach can be helpful in avoiding the consequences of deconditioning and resultant long-term disability.

Classification

The following classification categories are based on the presenting symptoms and are very useful for determining prognosis, planning treatment, and diagnostic testing:

Table 13-1. Duration of Symptoms and Prognosis of Acute, Subacute, and Chronic Pain.

Type of pain

Duration of symptoms

Prognosis

Acute

Less than 6 weeks

60% of patients return to function within 1 month

Subacute

6-12 weeks

90% of patients return to function within 3 months

Chronic

12 weeks or longer

Much less likely to resolve

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  1. Nonspecific spinal pain
  2. Radicular symptoms
  3. Potential serious spinal condition (Table 13-2)

The most common diagnosis is nonspecific spinal pain. Although many theories have been suggested to explain this type of pain, none have been conclusively validated. Despite the many diseases that are known to be associated with back pain, the pathophysiology of the most common diagnostic group remains unknown. Nonspecific spinal pain is generally thought to be secondary to musculoskeletal dysfunction, but no consistent and specific finding has ever been found. For the rest of the potential diagnoses, the pathophysiology of back pain depends on the disease process underlying the patient's complaints.

Radicular back pain is usually associated with spinal nerve irritation or compression. Table 13-3 outlines the differential diagnosis of back pain and includes potentially serious spinal conditions-the last classification.

Etiology of Benign Back Pain

At present, the evolution of chronic back pain is thought to begin with end plate damage. The disk receives most of its blood supply from the end plate. Disk degeneration begins with this compromise in blood supply first near the end plate and later in the disk nucleus. In support of this mechanism, arteriosclerosis of the vascular tree leading to lumbar segmental arteries is also associated with increased incidence of disk degeneration and back pain complaints. Considerable evidence now suggests that the healthy lumbar disk is primarily innervated in the annulus and to a limited extent in the pulposis. With degenerative changes, innervation progresses and extends deeper into the nucleus pulposus. Inflammatory mediators have also been identified inside the disk during discography in patients who report concordant pain. Along with the pathologic process described, the loss of disk height has important consequences on spinal dynamics. The vertebral body has a three-joint articulating relationship with its adjoining vertebral bodies. The change in dynamics, and structural relationships stresses the synovial facet joints, which leads to osteoarthritis, with the potential of subluxation, segmental instability, and chronic pain. The paradoxical reports of patients with advanced radiographic degenerative findings and little discomfort could be explained by the conclusion of this process through complete loss of mobility in the spinal segment by autofusion. Genetics is also thought to play a role in the susceptibility to back pain. A particular person's susceptibility is determined by the reaction to an injury as initiated by inflammatory mediators that are released and expressed along with differences in the underlying structural composition of the disk. Genetics appear to be significant early in a person's life; other risk factors, such as injury, lifestyle and nutrition, have a more important role after the second decade.

Hurri H et al. Discogenic pain. Pain. 2004; 112:225.

Mahmud MA et al. Clinical management and the duration of disability for work-related low back pain. J Occup Environ Med. 2000;42:1178.

Table 13-2. Back Pain Classification Based on Pathophysiology.

Classification

Description of presenting symptoms

Pathophysiology

Nonspecific spinal pain

Localized pain
Usually minimal or no physical findings

Unknown
Could be secondary to change in the dynamics of the spinal elements

Radicular symptoms

Radiating pain usually dermatomal

Usually spinal nerve compression or irritation, or both

Potential serious spinal condition

See Tables 13-3 and Tables 13-4

Depends on diagnosis

Table 13-3. Overview of Differential Diagnosis of Back Pain.

1. Rheumatologic conditions

1. Seronegative spondyloarthropathies

1. Ankylosing spondylitis

2. Psoriatic arthritis

3. Reactive spondyloarthropathy, including Reiter syndrome and enteropathic arthritis

2. Rheumatoid arthritis

3. Polymyalgia rheumatica

4. Nonarticular rheumatic disorders (eg, myofascial pain)

2. Cancer

1. Primary tumors of the spine

1. Multiple myeloma

2. Other bone or cartilage tumors, such as osteoid osteoma

2. Metastatic spinal disease

3. Infections

1. Osteomyelitis

2. Discitis

3. Epidural abscess

4. Herpes zoster

4. Vascular conditions

1. Abdominal aortic aneurysm causes pain by rupture, erosion of adjacent structures, or dissection

2. Epidural hematoma

3. Hemoglobinopathy (eg, sickle cell disease)

5. Metabolic disorders

1. Osteoporosis (primary or secondary)

2. Paget disease

6. Referred pain

1. Pelvic disorders

1. Endometriosis

2. Torsion of organ or structure

3. Pelvic inflammatory disease

4. Prostatitis

5. Cystitis

2. Abdominal disorders

1. Pancreatitis or cancer of the pancreas

2. Duodenal ulcers

3. Renal pathology or stones

7. Spine structure problems

1. Facet joints

2. Spinal stenosis

3. Paraspinal muscles

4. Sacroiliac joint

5. Spondylolysis or spondylolisthesis

6. Nonspecific back pain

8. Other causes

1. Hip joint

2. Shoulder joints

3. Costovertebral joints

4. Trochanteric bursa

5. Guillain-Barré syndrome

6. Meningeal irritation

7. Fibromyalgia syndrom

9. Psychological factors (myriad of different diagnoses)

Table 13-4. A Methodical Approach to Rule Out Serious Causes (Red Flags) of Back Pain.

Evaluation

Features

Comments

Obtain a comprehensive history

A new onset of back pain and history of cancer
Predilection toward infections
New onset of back pain in patients older than 50 years of age
Metabolic bone disorder
Unintended weight loss

Even if there is no history of metastatic disease
Patients using immunosuppressive medications
Benign back pain usually presents in younger patients
Osteoporosis or hyperparathyroidism
Atypical in uncomplicated back pain

Determine the patient's chief complaint

History of significant trauma
Pain worse at night
Pain not relieved by any position
Change in bladder or bowel function
Bilateral radicular pain
Extreme pain unrelieved by any therapy
Numbness or paresthesia in the perianal region
Unexplained limb weakness
Progressive neurologic changes

Atypical for uncomplicated back pain
Atypical for uncomplicated back pain
Single dermatomal neurologic defect is usually benign

Perform a physical examination

Pulsatile abdominal mass

Fever with back pain
Pattern of physical findings not compatible with benign mechanical disease

Also look for enlarged aorta on flat plate of abdomen or other radiographic studies
Consider infection

Obtain laboratory tests

Elevated sedimentation rate
Elevated white count

Elevated in many conditions including metastatic disease, infection and rheumatic conditions
May be the only laboratory indicator in discitis or epidural abscess

Evaluate treatment response

Lack of response to conservative therapies

Reevaluate for other causes

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Assessment

Initial Evaluation

The evaluation of a patient with back pain is often not a straightforward process. The true cause of back pain is found in only 20% of cases. Despite this, the need to rule out serious illnesses that present as back pain requires a thorough evaluation of the patient in a methodical and cost-effect approach (Table 13-4). Usually, the initial history and physical examination along with basic laboratory tests are sufficient to identify patients who are at risk for serious disease or who have “red flags” (see Table 13-4) or who require further workup. Notice that obtaining radiographic films is not part of the initial evaluation.

Diagnostic Testing

Because of the long-term nature of low back pain, patients often request additional diagnostic testing; the temptation is to respond to patient's concerns even when no clear-cut reason exists. Understanding key points of a patient's history and the pathophysiology of spinal pain can be helpful in providing the appropriate care for these difficult cases. Patients who are not responding to treatment as expected should be reevaluated with consideration given to a potential alternate diagnosis. Table 13-5 outlines disease categories, differential diagnosis along with key points, and the presumed underlying pathophysiology.

Despite the myriad of conditions that can cause back pain as listed in Table 13-5, discogenic back pain is

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thought to be the most common source of pain for nonspecific back pain. The evolution process begins with disk degeneration. As the process continues, secondary deterioration of facet joints, ligaments, and muscles follows, leading to a change in movement dynamics. Despite the temptation to associate structural changes seen on radiographic imaging of the spine with the cause of a person's pain, no such correlation has ever been proven. In addition, degenerative spinal conditions, which are asymptomatic but can be seen radiographically, do not necessarily predict future back pain complaints.

Table 13-5. Key Points for Spinal Pain.

Disease category

Key points

Pathophysiology

Comments

Rheumatologic conditions

Occurs in 1.9% of the white population
If patient is HLA-B27 positive, susceptibility is increased 20-fold
The SI joint is the most commonly involved joint and affected in 50% of cases

Genetic predisposition with environmental triggers

The most common spine manifestations in this class is Reiter syndrome and ankylosing spondylitis

Neoplasm (primary or metastatic)

Metastatic disease is 25% more common than primary tumors
Spinal metastasis is found in 70% of patients with primary tumors
The most common tumors that metastasize to the spine are breast, lung, prostate, kidney, lymphoma, melanoma, and the GI tract

Metastatic disease is spread by the venous channels in the epidural space (Batson plexus)

Multiple myeloma is the most common primary spinal malignancy
Rare below 40 years of age

Infections

General incidence is unknown for bacterial and fungal infections
Presence should be suspected in patients with localized pain to percussion and reports of fever
Spine infections are frequently misdiagnosed on initial presentation
Consider herpes zoster infection

May be acute or chronic
Causes vary from postspinal surgery infections to local seeding from deep tissue infections to remote seeding
Herpes zoster causes dermatomal neuropathic pain

Acute infections are usually associated with pyogenic organisms
With chronic infections, consider fungal infection or TB
Herpes zoster can mimic radicular symptoms

Vascular, hematologic

Half of all patients with ruptured abdominal aortic aneurysm complained of back pain first
Rarely, back pain can be caused by epidural hematomas
Inherited hematolgic diseases, such as thalassemia or sickle cell disease, are commonly associated with spinal pain

Pain caused by compression of adjacent structure by rapid enlargement of vessel
Sickle cell disease or thalassemia cause pain through bony infarcts

Epidural hematomas are associated with anticoagulation therapy, trauma, or recent spinal procedure (such as epidural)

Endocrine or metabolic osteoporosis

Osteoporosis is most common and often seen in older women

Risk factors include thin, white, postmenopausal women; smoking; alcohol intake; and sedentary lifestyle
Pain caused by compression fractures or microfactures of affected bone
Up to 50% of fractures are painless

Other risk factors include nutritional disorders, drug effects, genetics, and endocrine disorders

Paget disease

Paget disease contributes to pain directly about 2% of time

Unknown how Paget disease contributes to pain

Treatment of Paget disease often improves pain

Referred pain

Incidence as cause of back pain is unknown

Pain referred to the back from other disease is common with visceral pathology, such as endometriosis, pulmonary embolism, and ulcer disease

Abdominal and retroperitoneal disease most commonly referred to as lumbar spine
Other areas, such as chest, are less common

Mechanical causes of spinal pain

98% of all causes of spinal pain are from this category

These pains have much in common for presentation
Pain is primarily caused by inflammatory factors followed by mechanical derangement
Pain persisting after previous spinal surgery is not uncommon
A complete understanding of the cause is unknown

Structures that can originate pain include muscle, disk, facet joint and capsule, ventral dura, anterior posterior ligaments, and dural root sleeves

Other sources of spine pain Hip pathology

Hip pathology is an unusual cause for back pain

Pain is rarely referred to the buttocks, most common to the groin

Check range of motion hip

Guillain-Barré syndrome

Rare cause of back pain

Inflammation of the spinal meninges and stretching of them cause the pain

Distinguish from bacterial infections or neoplastic infiltration

Meningitis

May be acute or chronic

Inflammation of the spinal meninges and stretching of them cause the pain

Lumbar puncture definitive

Psychological causes

Unknown incidence
Studies show that true psychological causes are very rare

Unknown

Psychological stressors can contribute to pain

SI, sacroiliac; GI, gastrointestinal; TB, tuberculosis.

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Evaluation of Musculoskeletal Back Pain

Estimates have suggested that as much as 98% of back pain arises from the disruption of the musculoskeletal system supporting the back. Despite this high incidence, finding the pain generator that explains the source of back pain is often elusive. This is in part secondary to the many different components of the spine that are pain sensitive. In addition, any particular injury may effect one or more painful components of the spine. Pain sensitive structures of the spine include:

  1. Outer annular fibers of the intervertebral disk.
  2. The anterior and posterior longitudinal ligaments surrounding the disk.
  3. The facet joint capsules.
  4. Paraspinal muscles.
  5. Ventral side of the dura mater.

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  1. Dural root sleeves.
  2. The spinal nerves themselves, when irritated.

These pain sensitive structures-separately or in combination-form many of the common clinical diagnoses that are thought to underlie mechanical back pain.

Carragee EJ. Clinical practice. Persistent low back pain. N Engl J Med. 2005;352:1891..

Cherniack M et al. Clinical and psychological correlates of lumbar motion abnormalities in low back disorders. Spine J. 2001; 1:290..

Cohen R et al. Primary care work-up of acute and chronic symptoms. Geriatrics. 2001;56:26..

Devereaux MW. Neck and low back pain. Med Clin North Am 2003;87:643..

Pennekamp W et al. Feasibilities and bounds of diagnostic radiology in case of back pain. Schmerz. 2005; 12:117.

Differential Diagnosis

Table 13-3 presents an overview of a differential diagnosis of back pain that include less benign causes of back pain. Rheumatic conditions often present with significant morning stiffness. With light exertion, the pain commonly improves; later in the day with sustained activity the pain begins to increase again. Typically, the spine is more generally affected in rheumatic conditions. In some instances, the disease is confined to a discrete area; the diagnostic approach for discrete areas of pain is covered in the mechanical spinal pain section. Although helpful, a complete history and physical examination are rarely diagnostic. A specific history of symptoms involving the eyes, skin, and gastrointestinal tract can be very helpful for some of these diagnoses. Laboratory tests and radiologic imaging are frequently necessary for definitive diagnosis. Table 13-6 presents a diagnostic approach to the rheumatic pain conditions.

There are a couple of characteristic findings that differentiates neoplastic spinal pain from benign spinal pain. First, pain that wakes a patient up at night typically indicates neoplastic pain. Second, percussion of the spine is often painful with neoplastic disease but not benign spinal pathology.

Table 13-7 lists nonmechanical causes of spinal pain, clinical findings, and potentially helpful diagnostic approaches.

Structural Pathologies of Back Pain

Discogenic Back Pain

The disk is the largest avascular structure found in the body. Back pain, which arises from this structure, is known as discogenic back pain. Degeneration of the disk results from desiccation of the disk secondary to the breakdown of nucleus pulposis constituents, including proteoglycans and loss of collagen protein crosslinking. Repetitive daily activities, such as chronic axial and rotational forces, can lead to a weakened disk causing the development of microtears of the annulus and healing with fibrosis formation. This eventually leads to diminishing of the blood supply and further degeneration. Periodic complaints of back pain with resolution are thought to be secondary to this process. Acute annular tears may be the most common cause of back pain. Patients often report a feeling of a pop, which began with a flexion motion while lifting an object. Pain associated with this injury is increased by flexion and sitting (especially in a car). Unless the spinal nerve is compromised, the pain is nonradicular, with the physical examination revealing paraspinal muscle spasm but no neurologic deficits. Straight leg-raising test is negative, but patients sometimes report increased back pain. Flexion of the spine is limited. Internal disk disruption is a similar condition that is also associated with back pain. The frequency of leg pain is more common. Magnetic resonance imaging (MRI) studies often show a desiccated disk seen as dark shading in the involved level. The pain is thought to be from annulus tears leading to inflammation and abnormal movement of the spinal segment. Provocative discography followed by computed tomography (CT) scan showing leakage of contrast into the epidural space is confirmatory. Further injury to the disk, which includes progressive annular disruption, can lead to the protrusion of nucleus pulposis into the outer annulus seen as a bulging disk. At first, the posterior longitudinal ligament contains the disk material. If the posterior longitudinal ligament weakens, the nucleus pulposis may herniate and lead to either nerve root inflammation or frank compression, or both. Nociceptors found in the dural sleeve, dura, and posterior and anterior longitudinal ligaments contribute to the back and leg pain commonly found in these patients. Midline herniation of the disk can leave the patient only with back pain and little or no leg pain. Herniated disks are often associated with a flexion-type of injury associated with lifting and twisting. Patients may report a snap or pop at the time of injury. Severe pain is not always reported immediately but may worsen over several days. Large disk herniations can cause significant spinal stenosis with neurologic compromise, leading to cauda equina syndromes. These conditions must be looked for because they could require emergent surgeries to avoid irreversible neurologic injury. In these conditions, the patient may have a history of muscle weakness and the loss of bowel or bladder control. Physical examination reveals ipsilateral or bilateral positive straight leg-raising. True bilateral positive straight leg-raising is considered to be nearly confirmatory for spinal nerve root irritation.

Table 13-6. Diagnostic Approaches in Evaluating Rheumatologic Conditions Causing Back Pain.

Diagnosis

Clinical findings

Laboratory tests

Imaging studies

Comments

Ankylosing spondylitis

Usually affects patients between ages of 30-40 years
More common in males than females; can be confused with seronegative
RA. Dull, diffuse low back pain with referral to the legs and buttocks is common presentation
Later, extreme morning stiffness and severe night pain
Patient is in a slightly flexed trunk position

90% of patients are HLA-B27 positive
Note: test is not specific due to high prevalence (10%) of HLA-B27 positive in general population

X-ray films show definitive sacroiliitis CT scans of SI joint more sensitive, but less discriminating
Bone scans somewhat helpful
SPECT and MRI about 50% accurate only
Later in the course, “bamboo” appearance on plain x-rays

Most common of the seronegative spondyloarthropathies
Occasionally, symptoms include peripheral joints
Late presentation includes respiratory compromise and unmovable back

Psoriatic arthritis

Usually seen in older patients with skin changes typical of psoriasis over elbow or knees

No specific laboratory tests
Can find increase in ESR levels and anemia

Look for peripheral joint involvement
Findings similar to Reiter syndrome

Found in 5-7% of patients with psoriasis

Reactive spondyloarthropathies

 

 

 

 

Reiter syndrome

Reiter is very common in males
Usually, pain is located in lumbar spine, and legs Look for mucocutaneous lesions of the mouth, genitals, palms, soles, and nails

ESR can be elevated but variable
Synovial fluid analysis shows elevated WBC count

SI joint inflammation on CT scan

SI joint is the most common site of pain

Enteropathic arthritis

Symptoms of reactive arthritis associated with inflammatory bowel disease

No specific laboratory tests

No specific radiographic tests

Enteropathic arthritis is a form of reactive spondylitis and sacroiliitis

RA

Symptoms can affect the entire spine because of spondyloarthropathy
Cervical area is most commonly affected
Typical patient is female, young to middle age
Patient usually has morning stiffness, weight loss, fatigue, and low-grade fever

Anemia
Elevated ESR levels 80% of patients have a positive rheumatoid factor
Synovial fluid analysis shows elevated WBC counts, decreased viscosity, low glucose

Plain x-ray films of peripheral joints
Periarticular joint swelling
Osteopenia
In the cervical spine, late findings include atlantoaxial subluxation and multiarticular changes

See text
Peripheral joints affected first, which are swollen, tender to palpation, joints boggy to palpation
Course of RA is highly variable

Myofascial pain

Regional or localized muscle or ligament pain
Often associated with history of trauma
Loss of range of motion in the extremity is an important finding

No specific laboratory tests

No specific radiographic tests

See Chapter 15
Presence of trigger points is diagnostic

CT, computed tomography; ESR, erythrocyte sedimentation rate; MRI, magnetic resonance imaging; RA, rheumatoid arthritis; SI, sacroiliac;
SPECT, single photon emission computed tomography; WBC, white blood cell.

Table 13-7. Nonmechanical Conditions That Cause Spinal Pain.

Diagnosis

Clinical findings

Laboratory tests

Imaging studies

Comments

Fibromyalgia

Diffuse myofascial-like pain

No specific findings

Not helpful
No specific findings

See Chapter 15 for further information

Neoplastic disease

Back pain is the presenting symptom in 90% of patients
Pain is often indolent and unresponsive to rest
Pain most severe at night
Later in course, neurologic findings become common
History of recent weight loss

Elevated ESR, WBC counts, serum calcium and uric acid levels
Serum or urine electrophoresis for paraproteins diagnostic for multiple myeloma

Early-on metastasis may not be seen with plain films
Bone scans positive in 85% of patients
MRI can be diagnostic even when bone scans or plain films are normal

Presence of neoplastic disease is correlated with low back pain lasting longer than 1 month, history of cancer, age older than 50 years, failure to improve with conservative therapy, elevated ESR level, and anemia

Spinal infections

New onset of acute back pain in patients with history of recent infection, fever or severe pain at rest

Obtain an ESR level if patient has possible history, even if patient does not have a fever

Plain film findings lag significantly behind initial presentation
MRI or CT scanning is imaging of choice
Look for disk collapse

Osteomyelitis and discitis produce radiographic changes
Epidural infections are sometimes difficult to diagnose
Epidural abscess is a surgical emergency

Vascular problems, such as aneurysm, epidural hematoma, psoas muscle bleeds

50% of patients with abdominal aortic aneurysm complain of acute pain
Pain may radiate to hips
Look for hemodynamic instability
Mass may be palpable
Consider epidural hematoma with a history of trauma, anticoagulation therapy, or spinal block; focal spinal pain that is not relieved by rest
Psoas muscle bleed associated with pain on extension of the hip

No specific laboratory tests

Outline of aneurysm may be seen on plain films
CT scan is often definitive
For epidural hematomas, MRI is definitive

Epidural hematomas are rare causes of back pain
If not diagnosed promptly, irreversible neurologic injury can occur

Hematologic inherited hemoglobin-opathies

History of these conditions

Hemoglobin electrophoresis proving presence

Possible confirmation of bony infarcts
Presence does not prove or disprove presence of pain

Often very few objective findings with acute pain episode

Endocrine or metabolic

 

 

 

 

Osteoporosis

Pain often has acute onset and is very severe, gradually diminishing over a few months
Spontaneous 46% of time
Trivial trauma in 36% of patients
Found in postmenopausal women and in persons with genetic disorders

No specific blood tests

Radiographic imaging for fractures
Bone scan for determining age of fractures
Various approaches to determine presence of osteoporosis

Patient demographics for risk factors include, history of smoking, alcohol intake, nutrition history, and medication history

Paget disease

Rarely has pain

Elevated alkaline phosphatase

Characteristic finding on plain x-ray films of skull or long bones

May be familial
Treatment may include calcitonin or bisphosphonates in symptomatic disease

Referred pain

History specific for conditions
Consider if colicky pain, periodicity with menstrual cycle, atypical presentations
Histories of visceral problems are helpful

Laboratory testing for diagnosing specific conditions

Radiographic imaging for diagnosing specific conditions

Colicky type of pain very uncommon from back

Mechanical causes of spinal pain

Increase of pain with postures that increase pressure on spine, such as sitting, maintaining a posture for a long time, stretching of injured tissues
Look for increase of pain with specific movements

Laboratory tests usually not helpful
Helpful to rule out other causes

Plain radiographs are not very helpful
MRI and other testing may show changes, but poor correlation with etiology of pain

See Figure 13-1

aExamples include sickle cell anemia, sickle cell hemoglobin-c disease, and sickle cell β-thalassemia.
CT, computed tomography; ESR, erythrocyte sedimentation rate; MRI, magnetic resonance imaging; WBC, white blood cell.

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MRI or CT scan is confirmatory. Myofascial pain, degenerative spine disease, foraminal stenosis, epidural fibrosis, and even peripheral neuropathies should also be part of the differential diagnosis for this type of clinical presentation.

Spinal Stenosis

The long-term degenerative changes of the intervertebral disks leads to significant changes in the loading and stress of movement in the facet joints, postural muscles, and ligaments of the spine. Once begun, these processes can lead to spine instability and further mechanical disruption, which also eventually extends to neighboring vertebral bodies. Early in the course of spinal stenosis, the neuroforamen remain open with extension but narrow with flexion. At this stage, patients will only report pain with flexion. The continued trauma can lead to spinal nerve adhesions causing traction on the nerve root resulting in pain. Reparative processes lead to new bone growth resulting in spurring, calcification of ligaments, narrowing of the spinal canal and the neuroforamen. If the narrowing continues, the spinal stenosis can become critical, which leads to neurogenic claudication. Congenital spinal stenosis that is rarely significant at a younger age places a patient at higher risk for developing clinical significant symptoms later in life. Patients often report low back pain, either intermittent or constant, that may radiate to one or both legs. Pain is increased with ambulation and decreased by rest. Pain is relieved by rest or lying down. Critical spinal stenosis leads to a feeling of leg heaviness and diffuse anterior thigh numbness and occasional pain. The classic description of neurogenic claudication by a patient is calf pain relieved by rest and ambulation distance improved by a hunched forward gait facilitated by a cane, walker or grocery cart. The disease may or may not be progressive. On physical examination, neurologic changes may or may not be present. CT and MRI scans confirm the diagnosis; CT scanning shows the bony elements best, and MRI visualizes the microelements better. Significant spinal stenosis can also be caused by spondylolisthesis. The pain arises from either disk pathology or the posterior longitudinal ligament through shearing forces because of abnormal movement. Instability of the vertebral body only worsens the clinical picture. Flexion and extension films showing the pathologic movement confirms this diagnosis.

Facet Joint Pain

The dual facet joints found superior and inferior on each vertebral body form the basic articulation surface along with the intervertebral disk that allows spinal column movement. The facet joint is a true diarthroidal joint with articular cartilage and a synovial capsule that is richly innervated with nociceptors. Thus, the facet joint has the potential of significant pain, although making a clinical diagnosis remains very difficult and controversial. Despite the importance of the facet joint in spinal mechanics, the true incidence of pain from this structure remains unknown. As with all synovial joints, chronic inflammation and stresses that come from change in articulation forces as seen with disk degeneration lead to loss of articular surface and potentially chronic pain. Further deterioration leads to abnormal motion, subluxation and increased instability, eventually evolving into spondylolisthesis. Synovial cysts with nerve irritation or compression can also lead to radicular pain. In addition, the sclerosis induced by this process can lead to foraminal stenosis and or even spinal canal stenosis. Because of the proximity to the spinal foramen, inflammation, instability, and stenosis can lead to either local or radicular pain patterns. Patients with facet joint pain often report nonspecific back pain radiating at times to buttocks and even down the legs stopping at the knees. Pain is increased with rotation of the back, standing erect, spine extension, and lying prone. Neurologic examination is normal. Paravertebral muscle tenderness can also be elicited by palpation. Radiographic examination is not diagnostic. Single photon emission computed tomography (SPECT) scanning may be helpful for detecting inflammation involving the joints. The only definitive way to diagnose facet joint pain is selective joint injection using local anesthetic and radiographic guidance.

Postspinal Surgery Pain

Persistent pain after back surgery is commonly seen in pain management centers. This diagnosis applies to those patients in whom an appropriate diagnostic workup has been done and no other new or recurrent disease can be identified. The etiology of postspinal surgery pain remains unknown, but proposed causes include the following:

  1. Continued degenerative process from the altered surgical anatomy
  2. Surgical nerve trauma
  3. Traction on neural elements from scar tissue
  4. Persistent pain secondary to central sensitization

Patients presenting with this syndrome often give a history of short-term relief from the original surgery followed by reoccurrence. Patients also report multiple surgical procedures because of failed fusions and persistent or recurrent disk pathology. The pain is often described in terms that suggest a neuropathic component. Since the clinical picture is often one of longstanding pain, severe deconditioning and psychological comorbidities are commonly seen. Pain is continuous and seems to be

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independent of activity. MRI with gadolinium enhancement usually confirms the presence of epidural scarring. Whether the epidural scarring and the persistent pain are causally related remains unproven.

Myofascial Back Pain

Low back pain from a primary injury to the back muscles and ligaments is thought to be a very common cause of back pain. Patients usually report localized symptoms caused by either an associated increase in activity from their usual norm or from acute injury. On examination, muscle tenderness and spasm are usually noted with decreased range of motion. Trigger points may also be palpable. No neurologic changes are noted. The patient with involvement of the piriformis muscle may report radicular symptoms. Patients with a history of diminished activity are at higher risk for this type of injury. However, when no clear cause can be found, nonspecific back pain is often the diagnosis in many patients.

Table 13-8 summarizes the different mechanical causes of spinal pain as well as the clinical presentation and imaging findings that can be used to further confirm the diagnosis.

Hip & Sacroiliac Joint Pathology

Both the hip and sacroiliac (SI) joints are often an unrecognized source of pain attributed to the back pain. Table 13-9 describes clinical considerations useful in the diagnosis.

Psychological Aspects of Back Pain

Longstanding chronic back pain often has a significant psychological component, which can impact the diagnostic workup, prognosis, and treatment. A chronic back pain history should also include a patient's mood, work history (if relevant), family dynamics, and any potential for secondary gain. Because of the nonspecific nature of back pain, a patient's level of pain is often called into question. Waddell signs have often been used to verify a patient's back pain complaints. The presence of Waddell signs should not interfere with the therapeutic relationship between physician and patient. The presence of three or more Waddell signs can be indicative of significant psychological distress. The five Waddell criteria follow:

  1. Abnormal tenderness on patient evaluation, such as subcutaneous tenderness.
  2. Abnormal results after performing orthopedic maneuvers, such as rotation of the shoulder reproduces sciatica, pressure on head producing back pain.
  3. Evidence of distractibility (eg, ability to perform a specific maneuver without pain when position changes; positive straight leg-raising test, but the patient is able to sit on the side of the bed with legs dangling).
  4. Nonphysiologic weakness or sensory disturbance or give way weakness on muscle strength testing.
  5. Overall patient reaction to physical examination of painful areas with embellishment of their symptoms.

Carragee EJ et al. Diagnostic evaluation of low back pain. Orthop Clin North Am. 2004;35:7..

Klauser A et al. Inflammatory low back pain: high negative predictive value of contrast-enhanced color Doppler ultrasound in the detection of inflamed sacroiliac joints. Arthritis Rheum. 2005;53:440..

Onesti ST. Failed back syndrome. Neurologist. 2004; 10:259..

Waddell G. Subgroups within “nonspecific” low back pain. J Rheumatol. 2005;32:395..

Waddell G et al. Observation of overt pain behaviour by physicians during routine clinical examination of patients with low back pain. J Psychosom Res.1992;36:77..

Diagnostic Approach to Back Pain

In general, mechanical back pain located in the lumbar and lower thoracic regions is associated with a change in posture. In higher areas of the back, movement or traction on the involved area induces pain. Commonly, mechanical pain is increased with loading of the back. Usually, postures such as sitting are more painful than standing. Lying down typically improves the pain in mechanical spine disorders. Figure 13-1 presents a stepwise diagnostic approach to mechanical back pain. This diagnostic algorithm (see end of chapter) can be very helpful in determining most causes of back pain. Because of the presence of multiple different causes or nondiagnostic clinical histories, physical examinations, or radiographic imaging, some back pain needs to be investigated further. Diagnostic procedures can be helpful in these situations to further refine the diagnosis and focus therapy that is likely to be more effective. Occasionally, diagnostic procedures can serve a dual purpose of providing therapy as well (see Treatment section below).

Diagnostic Procedures

Because of the difficulty in diagnosing the source of a patient's back pain, considerable interest has always been expressed in selective neural blockade for more definitive diagnosis. Typically, a diagnostic procedure (with the exception of discography) consists of inserting a needle that is guided radiographically to the area believed to be responsible for the patient's pain; local anesthetic and corticosteroid (to enhance the analgesia and potentially provide long-term relief) are then injected. Using

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the patient's report of pain relief as a guide, a diagnosis is then made that would allow more specific treatment or help plan a surgical procedure, if needed. Although this idea is very attractive, a consensus on the reliability and specificity of these procedures remain illusive. Several factors may be present that call into question the diagnostic validity of these procedures:

  1. Pain is a subjective complaint. Many different factors in a patient's background can influence reporting relief. In addition, these procedures are rarely placebo-controlled. Physician misperception of what the patient is reporting may also contribute to the unreliability of the diagnostic procedure.
  2. Pain may be episodic, and therefore, the nerve block may be falsely reported as helpful when it is not.
  3. There have been suggestions that local anesthetic deposited distally to the pain generator may also provide analgesia via antidromic spread.
  4. Despite radiographic control with the use of contrast, there still is potential of spread to surrounding areas affected by the pathologic process, leading to false positive results.
  5. Pain pathways are not necessarily hard-wired; the nervous system is capable of central sensitization and forming new pathways for nociception. Diagnostic neural blockade in this situation leads to an incomplete understanding of the neural anatomy.

Table 13-8. Mechanical Causes of Back Pain.

Source of pain

Clinical presentation

Imaging studies

Comments

Intervertebral disk

Pain can be sudden or gradual, often associated with an inciting event
Patient may report an audible noise with onset of pain
Pain is central and often radiates in the involved dermatome
Loading and maintenance of posture increases pain, flexion limited by pain
Internal disk disruption is thought to be a cause of nonradiating back pain

In the absence of “red flags,” imaging is usually not required
Disk degeneration and protrusion is found in 64% of the general population without pain
Provocative discography with or without CT scan be useful for diagnosing internal disk disruption

Acute episodes usually improve over several weeks
Often there are recurrences. 90% of patients improve; 10% become chronic

Facet joint

Cannot be reliably diagnosed clinically
Pain is usually lateralized to the paraspinal areas, increased by extension, lateral flexion, or rotation to the painful side
Pain is increased with posture changes

Facet joint changes seen on imaging have no meaningful correlation with patient's pain complaints
Bone or SPECT scan may be more helpful
Diagnosis can only be made with fluoroscopic-controlled facet injections

Difficult to make a diagnosis
Accounts for pain in 15-20% of patients

Spinal stenosis

Generally affects older population
History of recurrent or chronic pain
Pain aching, paresthesias, heaviness in the legs with walking
Rapid improvement in symptoms with sitting, stooping, or flexion of back

Plain films show spinal stenosis
Differential with vascular claudication by angiograms or other noninvasive vascular testing

Improved walking tolerance with uphill incline, pushing a grocery cart, or using a walker.

Paraspinal muscles

Pain vague or diffuse, aching quality
Muscles may have palpable tenderness, presence of trigger points
Muscles exhibit loss of flexibility

Not helpful

Pain often improved by rest and standing
Clear role of paraspinal muscles in spinal pain is unknown

Spondylolysis and spondylolisthesis

History and physical examination is not very helpful for a specific diagnosis
Pain increased by extension and improved with flexion

Necessary for diagnosis

In young patient, may be secondary to acute stress fracture

Adhesive arachnoiditis

History of spinal surgery, trauma, spinal infection, disk herniation or spinal bleeds
Pain often has elements of both neuropathic and musculoskeletal pain
May have varying degrees of numbness, which is nondermatomal and patchy

MRI may show clumping of nerve fibers or adhesive arachnoiditis or both

Presence of arachnoiditis does not prove patient has pain

Other sources of spinal pain

Joint pathology and bursitis in areas near the spine can mimic spinal pain
Physical examination findings include localized tenderness and restriction of range of motion in shoulder or hip joints
Bilateral symptoms are a “red flag” and should be more thoroughly investigated

Radiographic findings show joint pathology, which should suggest the possibility of arthritis.
Not as helpful for bursitis or myofascial pain

In patients with degenerative arthritis of the spine it is not uncommon to have hip or shoulder pathology as well
Myofascial pains such as piriformis syndrome can simulate radiculopathy

CT, computed tomography; MRI, magnetic resonance imaging; SPECT, single photon emission computed tomography.

Table 13-9. Clinical Considerations for SI and Hip Joint Pain.

Source of pain

Clinical presentation

Imaging studies

Comments

SI joint

Radiates pain often into ipsilateral buttock, posterior thigh, and groin
Pain is reproduced by pressure over joint, forced flexion on the involved side along with the extension and abduction of the contralateral side
Despite this, physical examination is not very reliable for this diagnosis

Often not helpful
Poor correlation with radiographic findings and pain
Pain is often not from joint but from ligaments and tissues stabilizing the joint

Often unrecognized source of low back pain

Hip joint pathology

Usually pain radiates to the groin or to the knee
May produce an antalgic gait sufficient to produce back pain, and in later stages causes dysfunction of the joints of the back

Plain films or MRI of joint usually definitive
Bone scan may be confirmatory

Internal and external rotation of the joint may reproduce the pain

MRI, magnetic resonance imaging; SI, sacroiliac.

These caveats should not lead to the conclusion that diagnostic nerve blocks have no usefulness. Caution should be used in interpreting the results, as with any diagnostic test. Most procedures used for treatment of back pain have a dual use, with the exception of discography (see Treatment section below).

Discography

Because of the poor correlation of radiographic imaging for discogenic pain, discography has been advocated as the definitive test. Radiographic guidance along with contrast can define a painful disk and provide information regarding abnormal structural anatomy. Changes in contrast spread along with the patient's pain report can be used to identify a diseased disk. In addition, discography may be used to complement other tests, such as myelogram or event MRI. Discography can also be used to define a painful disk when other imaging options, such as MRI in failed spinal surgery, are nonspecific. Multilevel positive discography can be suggestive of poor outcomes for fusion surgery as well. Injection of the disk with a corticosteroid has also been noted to have therapeutic value, although with an increased risk of disk infection. The components of the normal lumbar disk are made of gelatinous nucleus pulposis and outer dense laminated fibroelastic layer known as the annulus fibrosis. Unlike the cervical area, the facet joints in the lumbar area do not protect the nerve roots. Therefore, a posterior and lateral herniation of the disk with impingement of the spinal nerves is not uncommon. Discography is indicated when traditional diagnostic approaches, such as imaging studies and electromyography, have failed to determine

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a cause of persistent pain. Discography seeks to provoke pain that reproduces the patient's pain complaint; this is known as concordant pain. Discordant pain is pain that does not simulate the patient's pain. The procedure should be done on at least three levels, including an asymptomatic level for a control. For the procedure, water-soluble contrast is used to identify the appropriate needle location. Resistance to injection is noted, along with any pain that the patient reports. A healthy disk is not painful, and some resistance is normal.

 

Figure 13-1. Diagnostic approach to mechanical back pain. Complete history and physical examination fail to reveal “red flags”. CT, computed tomography; MRI, magnetic resonance imaging; SPECT, single photon emission computed tomography.

A syringe attached to a pressure manometer is often used to avoid over pressurization of the disk. The limit should be 100mmHg. Based on the patient's pain report, a second control disk is injected. If failure to elicit pain or discordant pain is reported, other levels may be done to identify the painful disk. Postprocedure CT scan can detect extravasation of contrast indicating a torn annulus. Although there are many variations of this procedure, the patient is placed in a prone oblique position. Under radiographic guidance, a 7-inch 22-gauge needle is inserted 1.5 inches from the midline and just below the level of the spinous process. Care should be taken to avoid advancement through the disk. Anteroposterior and lateral views are continuously obtained to ensure appropriate placement. A more lateral approach can facilitate the procedure in patients with extensive facet joint arthritic changes or significant disk degeneration. The L5-S1 disk is sometimes difficult to reach especially in females. If necessary, a paramedian or transthecal approach can be used at this level.

Antibiotic prophylaxis is mandatory for this procedure. Some experienced practitioners suggest intradiscal antibiotic either in addition to or instead of intravenous prophylaxis. In patients who are not allergic, cefoxitin is the preferred antibiotic because of its ability to penetrate the disk and its coverage of Staphylococcus epidermidis.

Pain secondary to the procedure is the most common complication and is usually self-limited. Other, more significant complications include discitis, trauma to the nerve roots, local damage to blood vessels, and even epidural hematoma.

Selective Nerve Root Injections

Selective nerve root injections have been used for a long time for both therapeutic and diagnostic goals (see Treatment section below).

Facet Joint Injections

Facet joint injections have been advocated as a significant treatment of mechanical back pain (see Treatment section below). Guided injections into facet joints with or without placebo injections have been suggested as a diagnostic tool. Minimal support for this approach for surgical decisions is found in the literature. As a diagnostic tool for radiofrequency procedures, this procedure has considerably more support.

Atlas SJ et al. Evaluation and treatment of low back pain: an evidence-based approach to clinical care. Muscle Nerve. 2003;27:265..

Cohen SP et al. Lumbar discography: a comprehensive review of outcome studies, diagnostic accuracy, and principles. Reg Anesth Pain Med. 2005;30:163..

Onesti ST. Failed back syndrome. Neurologist. 2004; 10:259..

Pang WW et al. Selective lumbar spinal nerve block, a review. Acta Anaesthesiol Sin. 1999;37:21..

Tuite MJ. Facet joint and sacroiliac joint injection. Semin Roentgenol. 2004;39:37..

Yuan PS et al. Nonsurgical and surgical management of lumbar spinal stenosis. Instr Course Lect. 2005;54:303..

Treatment

Despite reports of severe pain, most spinal pain is self-limited. In the absence of “red flags,” treatment should consist of appropriate medications for both neuropathic and nociceptive elements. Consensus recommendations based on the guidelines published by the Agency for Healthcare Research and Quality suggest a limited role for bed rest. Prolonged bed rest has no place in the treatment of spinal pain. Disuse muscle atrophy and generalized deconditioning can quickly develop, making treatment much more difficult.

Patient activity is often limited because of pain, so sufficient analgesia becomes extremely important to maintain appropriate activity. The management of chronic back pain treatment is based on the following three principles:

  1. Management of the nociception.Sufficient analgesia using medications, procedures, or both is fundamental for improving a patient's rehabilitative potential and restoration of activity. A general consensus exists regarding the use of a treatment continuum forback pain. In general, medication is tried first (Table 13-10), with procedures reserved for nonresponsive patients. Interventional therapies are generally considered prior to irreversible neurolytic procedures.
  2. Psychological and behavioral therapies. Chronicpain with all of its losses is commonly associated with comorbid disorders of depression and anxiety. In addition, premorbid psychological diagnosis that is inhibiting return to function also should be treated. See Table 13-11 for an overview.
  3. Rehabilitation.Longstanding pain is commonly associated with deconditioning. A comprehensive rehabilitation program that does more than just focus on a specific site of pain is extremely important for restoration of function. See Table 13-12 for selected rehabilitative therapies.

Table 13-10. Pharmacologic Management of Back Pain.

Drug class

Examples

Mechanism of action

Uses for pain management

Discussion

Opioids

Multiple different compounds, such as morphine, fentanyl, hydromorphone, hydrocodone, oxycodone

Primary analgesic action is on the µ receptor

Primary role in acute cancer pain Adjuvant role in neuropathic pain

Dependence liability with long-term use
Careful patient selection is needed

Nonopioids

Acetaminophen

Possible COX-3 receptor effect

As primary analgesic or in combination with opioids

Concerns about liver toxicity in long-term use and interactions with alcohol

NSAIDs

Both mixed NSAIDs and selective COX-2 inhibitor

Both a peripheral and central effect to varying degrees

Nociceptive pain, possible use in neuropathic pain

Caution in patients with cardiovascular disease

Psychotropics

Psychostimulants
Antipsychotics
Benzodiazepines

Different mechanisms

Adjuvant role as antiemetic
Helpful for sedation and delirium

Little use in mechanical low back pain

Anticonvulsants

Most useful first-generation includes carbamazepine
Second-generation includes gabapentin, pregabalin, lamotrigine, topiramate, and oxcarbazapine

Increase in inhibitory transmitters, sodium channel blockade, and others

Neuropathic pain
Possible role as adjuvant in acute pain

50% of patients with back pain are estimated to have a neuropathic component

Membrane stabilizing agents

Local anesthetics
Mexilitine

Sodium channel blockade

Neuropathic pain

Not effective for radiculopathies

Topical medications

Various OTC drugs
Lidocaine patch
Doxepin
Capsaicin
TCAs
Compounded drugs

Topical anesthetics
Substance P depletion

Localized hyperalgesia

Anecdotal evidence for back pain

NMDA antagonists

Ketamine
Dextromethorphan
Memantine

NMDA receptor

Potential opioid analgesia
Neuropathic pain
Modulate opioid tolerance

Anecdotal evidence for back pain

Muscle relaxants

Baclofen
Diazepam and other benzodiazepines
Carisoprodol
Chlorzoxazone
Metaxalone
Methocarbamol
Orphenadrine
Clonidine
Tizanidine
Cyclobenzaprine

Various mechanisms
Usually attributed to a central effect

Acute myofascial pain syndromes

Anecdotal evidence for chronic back pain
Carisoprodol may have dependence liability

α-Agonists

Clonidine
Tizanidine

Enhance opioid analgesia
Helpful for withdrawal symptoms

Headache and neuropathic pain

Tizanidine has muscle relaxant abilities in chronic back pain

Antidepressants

TCAs
SNRIs
SSRIs

Blockade of norepinephrine and serotonin reuptake. They each have demonstrated analgesic effect.

Generalized analgesic, specifically helpful with neuropathic pain

Potentially helpful for psychological comorbidities

COX, cyclooxygenase; NMDA, N-methyl-D-aspartate; NSAIDs, nonsteroidal anti-inflammatory drugs; OTC, over-the-counter; SNRI, serotonin-norepinephrine reuptake inhibitors; SSRIs, selective serotonin reuptake inhibitors; TCA, tricyclic antidepressants.

Table 13-11. Overview of Psychological Therapies.

Therapy

Description

Hypnosis and visualization

The patient is taught to visualize relaxing mental images, such as a secluded beach or peaceful meadow
This helps decrease anxiety and facilitates deep relaxation

Guided imagery

Directed visualization focusing on specific psychological issues using pain-decreasing images

Biofeedback

Relaxation technique to measure a physiologic phenomenon, such as muscle tension, and to provide an audible or visual feedback indicating a state of relaxation

Cognitive-behavioral therapy

This teaches various techniques, such as distraction training, cognitive restructuring, role-playing, or mental imagery

Group therapies

When well-planned and with appropriate patient dynamics, group therapy is very helpful
The interaction is planned to share important breakthroughs in insight, discuss progress with treatment, and different strategies for overcoming everyday obstacles to improvement

Family therapy

Patients and their families often feel angry with each other
The family can be a significant stressor but is an important source of support that is needed for progress
This approach attempts to bring insight on how to provide support without enabling continued disability

Table 13-12. Rehabilitative Therapies Useful for Back Pain.

Rehabilitative therapy

Description of treatment and goals

Modalities, such as heat, ice, ultrasound

These are temporary short-lasting therapies and therefore should only be used as adjuvant to an active rehabilitation

Stretching

Mild and controlled stretching prepares the patient for further activity
Care should be taken to avoid injuring tight muscles that have not been active for a long time

Cardiovascular exercise

Patients with chronic pain are very often deconditioned. A general aerobic program can increase endurance and activity tolerance. Aerobic exercise has antidepressant effects.

Work conditioning

This is a specific program that is used to prepare patient for return to work
A job description is obtained, and the goals of therapy should lead to the physical demands of that type of work

Strength training

This is usually focused on the site that was significantly weakened by the original insult
This approach is also used to train alternate muscle to supplement the site of original injury
Care should be taken to keep the goals realistic and avoid further injury

Orthotics and prosthetics

Adaptive aids are often very useful for return to function
The benefits of truly understanding a patient's impairments and creatively designing adaptive aids can be very helpful in enhancing function

Table 13-13. Procedure Efficacy and Diagnosis.

Diagnosis

Epidural steroid injection

Facet joint or medial bundle branch injection

Spinal cord stimulation

Discogenic pain

++

 

 

Herniated disk

+ + +

 

 

Spinal stenosis

+ + +

+

+

Foraminal stenosis

+

++

+

Facet arthropathy

++

+ + +

 

Myofasical pain

 

 

 

Failed spinal surgery

 

 

++

Key: +, minimal effectiveness and diagnostic usefulness; ++, moderate effectiveness and diagnostic usefulness; + + +, very effective and diagnostically useful.

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  1. Therapeutic Procedures

Multiple different procedures are known to be effective in mechanical back pain. Because of the overlap of pathology that is commonly seen in patients with mechanical back pain, efficacy of a procedure is sometimes used to establish a diagnosis (Table 13-13).

Procedures are often used to treat back pain. As both the structural and neuroanatomy have become better understood, many new procedures have been developed to treat backpain. Considerable controversy exists regarding how and when to use many of these procedures. Procedures are often introduced for widespread use before they have been sufficiently studied. In addition, because of the significant variability in presentation, studies of outcomes of treatment approaches in the medical literature are often difficult to interpret. When to use a procedure and what symptoms respond the best as well as the efficacy in various conditions remain unclear. In a recent review of 15,000 studies and 150 expert reviews using criteria that controlled for methodologic quality, only two procedures had enough literature support to definitively determine whether benefit was obtained. This review showed that epidural steroid injections showed short-term benefit, and spinal cord stimulation had a lack of overall benefit despite many studies showing that 50% improvement was noted in 50% of patients at 5 years. Yet, all pain practitioners know patients who have derived long-term benefits from the large variety of procedures. This discrepancy can only be explained by what has been known for a long time. As the specificity and selectivity of available procedures increase, the need to understand the patient and make an accurate diagnosis is paramount. The key points in using procedures to treat pain are patient selection; making an accurate diagnosis along with determining what the pain generator is in each patient; and avoidance of repeated procedures, which provide little or no long-term response.

Epidural Steroid Injections

  1. Indications

Administration of a combination of depot steroid injections and local anesthetic is helpful in a variety of conditions including radiculopathies, localized nonradiating spine pain, spondylosis, vertebral compression fractures, postherpetic neuralgias, and malignant pain syndromes secondary to localized metastasis.

Usually, a series of three injections are performed 1 month apart. For patients with partial relief, an evaluation should be undertaken before each injection to determine whether additional injections are needed. There is no evidence to suggest that more than three injections are of additional benefit within a 6-month period. For patients reporting continued pain, a comprehensive evaluation should be undertaken with reevaluation of the treatment plan.

  1. Complications

Epidural steroid injections should not be performed in the presence of local or systemic infections. Coagulation status must be normal to avoid epidural hematoma. Despite these precautions, epidural infection and hematoma can still occur. Other serious complications can include spinal cord injury and total spinal anesthesia with resultant respiratory depression, hypotension, and cardiovascular collapse. Unrecognized intravenous injections leading to local anesthetic toxicity of the central nervous system, heart arrhythmias, and even completeatony have occurred. Less serious complications include persistent paresthesia and worsened of the pain from needle trauma. Inadvertent dural puncture is a common complication with an incidence of at least 1% in experienced hands. Concerns have been expressed periodically regarding potential detrimental effects of corticosteroids on the meninges leading to arachnoiditis. Despite many years of experience, no association has been documented.

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Systemic corticosteroid absorption can have detrimental effects on patients with diabetic tendency. In addition, the potential of adrenal gland suppression should also be kept in mind. Adrenocortical suppression is certainly possible and is one of the limiting factors for repeating this procedure.

  1. Evidence for Efficacy

Epidural steroid injection is one of the most common procedures done for back pain. There is substantial evidence for at least short-term efficacy in the treatment of radiculopathies. Other nonmalignant conditions have less support, with mainly expert opinion and case series found in the literature. For malignant pain syndromes, epidural injections have been shown to be effective in cohort studies and case series. Patients with subacute back and leg pain are thought to be the ideal candidates. Efficacy is also better in patients without previous surgery. Patients with leg pain only have the best long-term outcomes. Patients with spinal stenosis usually have a less favorable prognosis, unless there is an acute increase in recent pain. Patients with preexisting psychosocial issues may have a less favorable outcome.

Caudal Epidural Injection

The entrance to the caudal canal is found through the sacral hiatus. This hiatus is formed in the midline by the incomplete fusion of the posterior elements of S4 and S5. The sacrococcygeal ligament covers this U-shaped area and is a landmark guiding needle placement.

Lumbar Selective Nerve Root Injection

  1. Anatomy

The lumbar nerves exit the intraspinal canal through their respective foramen, which are located immediately below the transverse process. The nerve divides almost immediately and gives off a branch to the adjacent facet joint. The para vertebral nerve also gives off branches to the sympathetic chain. The spinal nerve is accessible for blockade just distal to the spinal foramen.

  1. Indications

Neuropathic pain syndromes with etiologies such as herniated disk or malignant tumors will respond to this block. In addition, this procedure is used to diagnose pain conditions of the chest wall and lower abdominal area.

  1. Complications

Complications are usually rare. Intracord injections are rare. Occasionally, persistent paresthesias have been reported. Other complications include nerve root injury and intrathecal injection by errant needle placement or through a larger than expected dural cuff.

  1. Evidence for Efficacy

There is substantial evidence for short-term efficacy for treatment of radiculopathies. Other nonmalignant conditions have less support, with mainly expert opinion and case series found in the literature. For malignant pain syndromes, epidural injections have been shown to have efficacy with cohort studies and case series published. The selective nature and radiographic guidance used in this procedure may improve response and efficacy rates. This procedure is also used as part of the presurgical evaluation of radiculopathy.

Sacral Nerve Root Injections

  1. Anatomy

The sacrum is the terminal portion of the spine. It has a very irregular surface with four paired sacral foramina nerves. The five sacral nerves exit the spinal canal via the sacral hiatus. The sacral nerves provide sensation and motor innervation to the external anal sphincter and levator ani muscles. The second through the fourth sacral nerves provide the majority of sensation to pelvic viscera and external genitalia.

  1. Indications

Sacral nerve root injections can be used to diagnose neuropathic conditions of the sacral nerves and treat pelvic pain syndromes as well as radiculopathies.

  1. Technique

The sacral nerves can be blocked using a transforaminal approach with radiographic guidance; the beam is angled to visualize the approach through the posterior foramen. The needle is then inserted through the identified angle. A nonradiographic approach can also be used after identifying standard bony landmarks.

  1. Evidence for Efficacy

Nerve root injections have been shown in case series to be effective for nerve compression symptoms involving the sacrum. This procedure can also be used as part of a diagnostic workup for back, SI joint pain, or hip joint pain.

Lumbar Facet Joint Injection

  1. Anatomy

The facet joints are formed by the articulations of the superior and inferior articular facets of the lamina of the adjacent vertebrae. The joints are true synovial joints and extensively innervated. Each joint receives innervation

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from above and below as well as the level at which it is located.

  1. Indications

Lumbar facet joint injection is indicated for paraspinal thoracic pain secondary to trauma from twisting, acceleration-deceleration injuries, fractures, and neoplasm.

  1. Technique

Lumbar facet joint injection must be done under fluoroscopic guidance. Two approaches are described, either injection into the capsule of the joint known as a medial bundle branch block (MBB) or intra-articular joint injection. Depending on the procedure, the fluoroscopic beam must be aligned obliquely to visualize the joint or be in the anteroposterior position for the MBB. The needle is advanced to the middle of the articular pillar where the medial branch passes. With the intra-articular procedure, the joint surfaces are visualized by an oblique position of the fluoroscopic camera.

  1. Evidence for Efficacy

Numerous studies have shown efficacy for these procedures. No differences in outcomes have been documented for facet joint injections or MBBs. These injections have also been used to predict response to radiofrequency lesioning of MBB at the same levels.

Facet Joint Denervation

  1. Anatomy

The approach for facet joint denervation is essentially the same as the approach for an MBB.

  1. Indications

Facet denervation is indicated for patients who have reported short-term pain relief with a local anesthetic injection using the procedure as described for an MBB. Using RFL or other denervation techniques, longer-term relief can be obtained.

  1. Technique

For all procedures, the needle is advanced under radio-graphic guidance. For lumbar denervation procedures, a needle is advanced to the junction of the superior articular and transverse process. Sensory testing to determine appropriate location of the needle as well as anteroposterior and lateral views of the needle are required. Denervation is usually done after injection of a small amount of local anesthetic.

  1. Evidence for Efficacy

Many cohort studies and some randomized trials have provided evidence for efficacy.

Ablative Procedures for Discogenic Pain

Intradiscal electrothermaplasty (IDET), nucleoplasty, percutaneous disk decompression, and radiofrequency lesioning are all newly described procedures for discogenic back pain. Each procedure has different physiologic effects on the structure of the disk. In contrast to IDET, nucleoplasty as well as percutaneous decompression procedures improve radicular symptoms.

  1. Indications

Ablative procedures are indicated for chronic discogenic back pain that has lasted for at least 6 months and for patients who have not had satisfactory improvement after an aggressive exercise program. The patient should have a complete examination of the source of pain, including MRI without nerve compression, as well as normal findings on neurologic examination. The patient should have proven concordant pain as determined by discography, ideally at one level only. These procedures are most often used for a single painful disk with a minimum of 50% preservation of normal height. Contraindications include inflammatory arthritis, anticoagulation therapy, advanced spinal disease, and segmental instability.

  1. Technique

The approach is essentially the same as discography. A 17-gauge needle is inserted to guide placement of a probe, which is placed into the nucleus pulposis. Occasionally, bilateral approaches are needed to cover the entire disk. Using either radiofrequency or a heating element, the collagen and nociceptors are denatured after careful placement. Company-specific equipment is required to perform IDET, with defined protocols on the length and level of energy programmed into the energy source. With the disk decompression procedure, a battery-operated device is inserted through the introducer needle that has been placed into the disk. The procedure is completed by turning on the device, which then mechanically decompresses the disk. Postprocedure rehabilitation is thought to be extremely important in successful outcomes.

  1. Complications

The complications are similar to discography, with the additional risk of thermal damage to the spinal cord and the spinal nerves. Several cases have been reported where the catheter has broken inside the confines of the disk. No long-term complications have been reported by leaving the broken portion of the catheter in place.

  1. Evidence for Efficacy

Several randomized studies and a number of short-term nonrandomized studies have shown efficacy. Long-term outcomes > 1 year in patients receiving these procedures remain unknown. Some studies have shown that outcomes compare favorably to spinal fusion.

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Vertebroplasty

  1. Anatomy

The relevant anatomy consists of the vertebral body, which is located between the disk spaces of the lumbar and thoracic spine. Little information exists regarding using this procedure in the cervical area.

  1. Indications

Vertebroplasty is performed for compression fractures with loss of height in the vertebral column secondary to osteoporosis or malignancies.

  1. Technique

Vertebroplasty must be done under radiographic guidance. Often monitored anesthesia care or conscious sedation is required. There are two different types of vertebroplasty, using methyl-methacrylate alone or a balloon filled with methyl-methacrylate. The approach of this procedure depends on the location of the fracture. The usual approach in the thoracic spine involves placement through the vertebral lamina. In the lumbar area, the approach is paravertebrally directly into the body. A 17-gauge needle is inserted through the lamina into the vertebral body bilaterally. The needle then serves as a guide for the cannula, which is then inserted into the fracture. The cement is usually mixed with radio-opaque materials, such as barium, to allow for visualization. Cement volume is usually equally divided into bilateral injection sites, which prevents unequal height restoration. Cement volume can vary from 0.5 mL to 4.0 mL. Care should be taken to avoid increased injection pressures, which can lead to extrusion of the cement, which could lead to complications. Postprocedure CT scan is undertaken for verification of appropriate cement placement.

  1. Complications

Many serious but rare complications have been reported for the methyl-methacrylate, including cement embolism, spinal cord injury by unrecognized injection into the epidural space, and somatic nerve injury from placement of the cannula.

  1. Evidence for Efficacy

Many case series have reported efficacy for this procedure with long-term follow-up.

Intraspinal Neurolytic Procedures

  1. Anatomy

See description under nerve root injections, above.

  1. Indications

Intraspinal neurolytic procedures are indicated for malignant conditions in patients with limited life-expectancy.

Care must be taken to carefully select patients in whom loss of motor function and loss of bowel or bladder control would not adversely affect their quality of life. This procedure has little place in the treatment of noncancer pain. Some investigators are advocating the use of pulse radiofrequency lesioning of the dorsal root ganglion in chronic radicular neuropathic pain syndromes.

  1. Technique

Neurolytic procedures on selected nerve roots can be done in patients with malignancies. Approaches include selective rhizotomies or neurolysis of the involved nerve root using either extradural or intradural techniques, most often done with radiographic guidance. Usually, the nerve root is first blocked with local anesthetic to determine pain relief potential and possible loss of function. The neurolytic procedure is then scheduled at a different time. For selective intrathecal rhizotomies, the patient is placed in a lateral position. When alcohol is used, the patient is positioned with the painful side up to allow for the hypobaric nature of alcohol. The volume of fluid used is specifically tailored to the levels required to achieve analgesia. High volumes can be used for patients in sitting positions to treat sacral nerve roots. Smaller volumes are needed for individual nerve root rhizotomies. These procedures should only be performed in extreme circumstances when adjacent to nerves controlling bowel, bladder, or limb function or in the upper cervical levels. For epidural procedures, the patient is often prone, and a catheter is placed at the appropriate level. Phenol is the preferred epidural neurolytic agent.

  1. Complications

Unintended loss of function is the primary complication that may be minimized by using small volumes and carefully selecting patients. Proximity to areas of the spinal cord controlling limb function increases risk.

  1. Evidence for Efficacy

There is substantial case experience in the literature to support use in cancer pain. There is very little evidence supporting the use of these procedures for chronic non-cancer pain.

Epiduroscopy

  1. Anatomy

The most common entry point is the caudal canal. Please see caudal steroid injections for more details regarding the anatomy and technique.

  1. Indications

Proponents of epiduroscopy suggest that direct visualization of the spinal canal can add an extra dimension

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to diagnosing spinal disease. The promise of a visually guided procedure would potentially increase the efficacy rates. In addition, spinal adhesions that are not able to be diagnosed by any other method could be seen and lysed by direct visualization.

  1. Technique

The scope is inserted into the epidural space often using radiographic guidance through a previously placed cannula. Irrigation is used to improve visualization.

  1. Complications

Complications are similar to other catheter procedures in the epidural space and include infection; bleeding, potentially leading to epidural hematomas and nerve compression; and nerve damage with permanent impairment of function. In addition to visualization of spinal pathology, a specialized technique using a wire reinforced catheter known as epidural lysis of adhesions has been described. This catheter can be placed either with an epidural needle or the epidural scope.

  1. Evidence for Efficacy

There are no randomized prospective clinical trials available to verify the increased efficacy that proponents of this procedure suggest. With further development, this procedure and appropriate instruments hold the promise of a whole new approach to the treatment of difficult to manage chronic back pain.

Epidural Decompressive Neuroplasty

  1. Anatomy

The relevant anatomy is the same for epidural catheter placement.

  1. Indications

The procedure is indicated when adhesions of the epidural space are suspected, which can restrict movement or cause traction on the neural elements. Adhesions are thought to underlie some intractable chronic back pain. Previous surgery, trauma, or infection is thought to cause adhesions that are amenable to this procedure.

  1. Technique

This procedure requires radiographic guidance, a specialized wire-wound epidural catheter, and contrast. With the patient typically under conscious sedation, the catheter is inserted into the epidural space at a location several vertebral bodies below the area of suspected disease. For lumbar procedures, the caudal canal is used. Corticosteroids, local anesthetics, and mild neurolytic solutions (such as hypertonic saline) have been advocated for this procedure.

  1. Complications

Complications are similar to those described for epidural catheters. Neurolytic solutions and aggressive technique can damage the spinal cord and nerve roots.

  1. Evidence for Efficacy

Large case series have reported improvement.

Sacroiliac Joint Injections

  1. Anatomy

The SI joint is a synovial joint that forms the articular surface of the sacrum and ilium on either sides of the sacrum. This joint is irregular in contour and is matched on the ilium side with reciprocal irregularities. An articular capsule covers the joint and attaches to the periphery of the articular surfaces.

  1. Indications

Injections are indicated for SI joint pain that is determined on physical examination. This procedure is also indicated as a diagnostic procedure for surgical intervention. The incidence of SI joint pain may be as high as 30% in patients reporting chronic low back pain.

  1. Technique

Using radiographic guidance, the SI joint is identified. A 22-gauge needle is introduced about 2 cm medial at an angle into the joint. Placement can be confirmed by the use of contrast and anteroposterior and lateral views. Alternatively, CT scan can be used for confirmation of needle placement.

  1. Complications

An increase in local pain is not uncommon. Local anesthetic can leak through the joint and anesthetize both sacral and lumbar somatic nerves.

  1. Evidence for Efficacy

Numerous case series have confirmed short-term efficacy for the corticosteroid injection procedure. Radiofrequency lesioning of the joint has shown prolonged improvement in one case series.

Spinal Cord Stimulation

  1. Anatomy

The bounds of the epidural space have been described above. Location of involved spinal nerves determines location of the stimulating electrodes in the epidural space.

  1. Indications

Electrical stimulation of the central nervous system has long been used for analgesia in neuropathic pain states. Although many theories exist as to the mechanism of

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analgesia, frequency modulation of the central nervous system masking the neuropathic sensation is the leading explanation. Epidural placement of multielectrode arrays can be effective for a variety of conditions and are helpful for a diverse number of neuropathic pain conditions, including failed spinal surgery. Screening trials showing at least 50% efficacy is a very important prognostic factor for long-term efficacy. Preprocedure psychological evaluation is also considered to be helpful in screening of potential candidates.

  1. Technique

Epidural placement of the electrode is similar to the placement of epidural catheters. Trial stimulation determines efficacy prior to implantation of the system. Fastidious attention to the fixation of the electrode is important to avoid movement and to achieve long-term efficacy. Two types of pulse generators exist: an external system that relies on radiofrequency current for power and a battery-operated implantable pulse generator (IPG). The IPG portion of the device can be implanted either in the buttock (over the greater trochanter) or in the abdominal wall (most common).

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  1. Complications

Complications are very similar to epidural catheter placement. In addition, because of the presence of a foreign body, surgical infections commonly lead to explantation of the device. MRI imaging is contraindicated in patients with spinal cord stimulation. The battery life of an IPG is limited and requires replacement on exhaustion. Battery life depends on the current use, number of active electrodes, and both rate and pulse width settings of each patient. Superficial skin irritation can limit therapy in patients with radiofrequency devices. Other complications unique to this procedure include electrode migration or fracture with consequent loss of analgesia. Patients walking through some theft detectors have reported IPG interference.

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  1. Evidence for Efficacy

Patients who are candidates for this procedure often have not responded to other therapies. The increased sophistication of these devices with multiple electrode arrays and patient-programming options have continued to improve efficacy in well-selected patients who have realistic treatment goals.

Neuroaxial Infusion Systems

  1. Anatomy

Epidural infusion systems are generally used only for short-term relief. Intrathecal catheters and fully implanted pumps are generally used for long-term therapy. Intrathecal catheters can be directed toward the appropriate level within the spinal canal. Care must be taken to avoid damage to the spinal cord. Commonly these catheters are inserted using a modified epidural needle that should be placed below the level of termination of the spinal cord, which is at L1. Special circumstances can exist when this is not feasible, such as previous fusion surgery or other anatomic abnormalities.

  1. Indications

Neuroaxial infusion systems are indicated for chronic intractable pain, which cannot be managed by more conventional means in a patient who is not a candidate for a surgical approach and who has responded poorly to oral medications. For noncancer pain, the most common indication is failed spinal surgery. As with spinal cord stimulation, patient selection is the key to long-term efficacy. Patients should have both a psychological screening test and neuroaxial medication trial. No clear consensus exists whether this trial should be an epidural or intrathecal catheter trial. Single shot trials are also considered predictive of success, although most experienced clinicians believe that catheter trials are a better predictor of success. Various medications and combinations are used to provide analgesia. These include opioids, local anesthetic solutions, baclofen, and clonidine.

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  1. Technique

The procedure is similar to that for epidural placement, except the needle is advanced into the intrathecal space. The presence of cerebrospinal fluid confirms placement. The intrathecal catheter is then advanced to the desired level. For back and leg pain, the catheter is typically advanced to the T12-T10 level. For the pump implantation, an incision and dissection is used to create a pocket sufficient in size to hold the pump. This pocket is usually located in the anterior abdominal wall; care must be taken so that the pump does not rub against the ribs and that its placement is away from a belt and elastic waistbands of a patient's undergarments. After the creation of the subcutaneous pocket, the spinal catheter is then tunneled from the posterior incision site to the pump pocket and attached to the pump.

There are two types of pumps: fixed flow and programmable. Fixed flow pumps are usually less costly and can hold more drug volume, but dosing changes require pump refills, which can become expensive with higher cost drugs and multiple dose changes. Programmable pumps can provide various programming options including complex infusion programs. Dosing changes are easily done, with programmed increase in the pumps infusion rate. Intrathecal administration is preferred over epidural for long-term therapy because of the greater potency of medications infused into the cerebrospinal fluid and the epidural fibrosis that is often found in patients with spinal surgery.

  1. Complications

There is a 1 to 5% reported risk of infection. Other complications are nerve injury, persistent paresthesias, and even paraplegia. Minor complications include pocket seromas, hygromas, and spinal headaches from cerebrospinal fluid leaks. Complications associated with refilling the pump include inadvertent side port injections especially in older pumps which lack safety screens. This mistake may deliver an intrathecal injection of months' worth of medication and provoke respiratory and cardiovascular collapse, even death. Programming errors are also potential complications, which can lead to death from drug overdoses.

Complications from spinal opioids include nausea and vomiting, urinary retention, and respiratory depression. Respiratory depression is unlikely in patients who are already tolerant to the effects of systemic opioids except when other systemic problems, such as pneumonia, occur; the respiratory depressant effects of opioids may become addictive with the development of such systemic problems.

Spinal opioid therapy can apparently be continued for years without significant complications. Recently, concerns about catheter granulomas have been raised. The mechanism of development is still being debated, but a noninfectious inflammatory response to the intraspinal opioid may be the cause. Severe neurologic compromise can occur when these granulomas enlarge and remain undiagnosed.

  1. Evidence for Efficacy

In most situations, no single medication can be effective for both neuropathic and nociceptive pain. Because of this observation, most experienced clinicians who implant neuroaxial systems choose medication combinations to provide optimal analgesia while diminishing side effects. There is substantial literature documenting case series and expert experience suggesting long-term efficacy in well-selected patients.

Trigger Point Injections

  1. Anatomy

Trigger points are characterized by areas of tender nodules or distinct bands of muscle, palpation of which can reliably refer pain to consistent locations on the trunk or extremities. Trigger points are identified by applying pressure over the presumed location until the patient's pain is replicated.

  1. Indication

Injection of trigger points may improve both the range of motion and the function of the affected area. This procedure may play a useful role in conjunction with a rehabilitation program.

  1. Technique

A trigger point can be injected either with a dry acupuncture needle or a needle filled with saline or local anesthetic with or without a corticosteroid. This procedure is often repeated during the rehabilitation program in order to treat recurrences. Recently, botulism toxin has been advocated for use during trigger point injections in order to treat resistant myofascial pain secondary to recurrent trigger points.

  1. Complications

Following the procedure, the pain elicited from the trigger point area may temporarily worsen. Misdirected needles may puncture adjacent organs and blood vessels. Inadvertent intravascular injection of local anesthetic may precipitate seizures or systemic toxicity. Botulism toxin injections can lead to systemic effects, such as widespread muscle weakness or even anaphylaxis in allergic patients.

  1. Evidence for Efficacy

Well-controlled outcome studies are limited, in part due to the lack of consistent criteria for the diagnosis of trigger points. Case series and small controlled studies have demonstrated short-term improvement. Case series suggest that botulinum toxin is efficacious. Multiple and repeated trigger point injections do not have any support for efficacy. Trigger point injections without rehabilitation are often ineffective as well.

Psoas Muscle Injection

  1. Anatomy

The psoas muscle lies deep to the transverse process of the lumbar spine. It originates at multiple levels from the transverse processes of each lumbar vertebra and typically courses below the inguinal ligament to insert with the iliacus muscle as a conjoint tendon onto the lesser trochanter.

  1. Indications

Treatment of deep, ill-defined back pain with occasional coincident groin pain may indicate psoas muscle spasm.

  1. Technique

With the patient prone, using either fluoroscopy with contrast or CT scan for radiographic guidance, two needles are inserted using a “loss of resistance” technique into the psoas compartment.

  1. Complications

Following injection of local anesthetic, the branches of the lumbar plexus, which traverse the psoas muscle, may be temporarily affected. Poor aseptic technique has led to infection of the psoas compartment.

Table 13-14. Low Back Pain and Diagnosis and Treatment Approaches.

Diagnostic categories

Treatment approaches

Rheumatologic

Refer to specialty care for primary treatment of disease
Use analgesic approaches as needed to maintain activity levels

Cancer

Refer to specialty care for primary treatment of disease

Infections of the spine

Refer to specialty care for primary treatment See Figure 13-7

Vascular

Refer to specialty care for treatment of primary pathology.

Metabolic

Refer to specialty care for primary treatment of disease See Figure 13-8

Referred pain (eg, pelvic and abdominal disorders)

Refer to specialty care
Refer to specialty care

Mechanical spine pain

 

 Discogenic back pain

See Figure 13-2

 Facet joints

See Figure 13-3

 Spinal stenosis

See Figure 13-4

 Adhesive arachnoiditis

Direct spinal cord stimulation
Microlysis

 Spondylolysis/spondylolisthesis

See Figure 13-5

 Paraspinal muscles

Trigger point injections
Massage
Physical therapy

 Nonspecific back pain

Limited rest, analgesics, antispasmodics, then resumption of normal activities to tolerance

 SI joint

See Figure 13-6

 Myofascial pain

Massage
Corticosteroid or anesthetic injections (or both)

Other causes of back pain

 

 Guillain-Barré syndrome

Refer for specialty care

 Herpes zoster

Look for rash and treat as a neuropathic pain problem

 Meningeal irritation

Refer for specialty care

 Fibromyalgia syndrome

See Chapter 15

 Hip joints

See treatment of osteoarthritides in Chapter 14

 Trochanteric bursa

See treatment of osteoarthritides in Chapter 14

Psychological factors

Refer for cognitive-behavioral therapy or other therapies as required after evaluation

  1. Evidence for Efficacy

Several cohort series suggest efficacy. Injection of botulinum toxin into the psoas muscle has been reported to decrease the duration of pain originating from persistent muscle spasm.

Piriformis Muscle Injection

  1. Anatomy

This muscle arises from the pelvic surface of the sacrum, the sacrotuberous ligament and the posterior portion of the ilium. The muscle then courses through the sciatic foramen to insert into the upper border of the greater trochanter.

  1. Indications

Injection of this muscle is indicated for assessment and treatment of piriformis syndrome. Patients presenting with this syndrome often complain of radiculopathy-like symptoms, which can be confused with lumbar radiculopathy.

  1. Technique

The muscle in thin persons can often be palpated; pressure on the muscle reproduces the symptoms. The muscle is approached in a similar fashion as the posterior approach to the sciatic nerve. A nerve stimulator or electromyography can be used to increase accuracy.

  1. Complications

With the sciatic nerve in the immediate vicinity, anesthesia and paresthesia can occur. Local pain and irritation is the most frequent complication.

  1. Evidence for Efficacy

Piriformis syndrome is a well-known syndrome and several case series have shown improvement with this procedure.

  1. Noninvasive Therapies

Table 13-14 divides the causes of low back pain into nine categories:

  1. Rheumatologic
  2. Cancer
  3. Infections of the spine
  4. Vascular
  5. Metabolic
  6. Referred pain
  7. Mechanical spinal pain
  8. Other causes
  9. Psychological factors

Figure 13-1 shows the diagnostic approach to mechanical pain. There are six treatment algorithms that demonstrate the approach to managing the various types of mechanical back pain, including discogenic spinal pain, facet joint pain, spinal stenosis, spondylolysis or spondylolisthesis, and SI joint pain. Other treatment algorithms outline the approach to managing spinal infection, metabolic bone disease, and failed spinal surgery.

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Cohen SP et al. Nucleoplasty with or without intradiscal electrothermal therapy (IDET) as a treatment for lumbar herniated disc.SpinalDisord Tech. 2005;18 Suppl:S119..

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Figure 13-2. Treatment of discogenic spinal pain. Spinal pain due to torn annulus, internal disruption, or prolapsed intervertebral disk. IDET, intradiscal electrothermoplasty. A and B = Go to corresponding letter within algorithm.

 

Figure 13-3. Treatment of facet joint pain. Pain, with or without referred pain, stemming from one or more facet joints; pain due to sprains or other injuries to the capsule of facet joints or arthritic changes. A = Go to corresponding letter within algorithm.

 

Figure 13-4. Treatment of spinal stenosis pain. Pain due to narrowing of the vertebral canal at multiple levels, usually of the cervical or lumbar vertebrae. A = Go to corresponding letter within algorithm.

 

Figure 13-5. Treatment of spondylolysis or spondylolisthesis.

 

Figure 13-6. Treatment of sacroiliac (SI) joint pain. A = Go to corresponding letter within algorithm. NSAIDs, nonsteroidal anti-inflammatory drugs; TENS, transcutaneous electrical nerve stimulation.

 

Figure 13-7. Treatment of spinal infection. Spinal pain in the context of specified infection or likely infection. A and B = Go to corresponding letter within algorithm.

 

Figure 13-8. Treatment of metabolic bone disease. A and B = Go to corresponding letter within algorithm.

 

Figure 13-9. Treatment of failed spinal surgery. A and B and C = Go to corresponding letter within algorithm.