SPINAL JOINTS

Discovertebral Joints

Each vertebral end plate is coated with a layer of hyaline articular cartilage (cartilaginous end plate). Adjacent vertebrae are united by a fibrocartilaginous intervertebral disk. Concentric, crossing layers of tough fibrous tissue, the annulus fibrosus, make up the outer circumference of the disk, enclosing a central, shock-absorbing gelatinous core, the nucleus pulposus (Figure 8-5). The intervertebral disks account for about one fourth of the height of the vertebral column above the sacrum. The sacrococcygeal vertebrae are fused and have no intervertebral disks. The disks are thickest in the lumbar spine and thinnest in the thoracic spine, and the cervical disks are intermediate in size. The intervertebral disks distribute the weight over the surface of the vertebral body and act as shock absorbers during loading, converting vertical load into horizontal thrust, which is absorbed by the elastic mechanism of the annulus. The disks provide a strong tie between the vertebrae yet allow a greater range of spinal movements compared with a solid column.

FIGURE 8-5 INTERVERTEBRAL DISK.

LIGAMENTS

Numerous ligaments stabilize the anterior and posterior elements of the spinal column. The anterior longitudinal ligament is a strong, broad fibrous band that runs from the occiput to the sacrum, where it anchors the anterior vertebral surfaces and intervertebral disks (Figure 8-6); it prevents excessive extension of the spine. The posterior longitudinal ligament also runs the length of the spinal column. It is a weak and narrow band but broadens where it attaches to the posterior intervertebral disks. Multiple ligaments also stabilize the posterior elements. The ligamentum flavum interconnects the vertebral laminae at the posterior roof of the spinal canal, and the weak interspinous ligaments and the stronger supraspinous ligaments interconnect the spinous processes. The latter two sets of ligaments partially limit forward and lateral flexion of the spine (see Figure 8-6). The intertransverse ligaments interconnect the transverse processes.

FIGURE 8-6 INTERVERTEBRAL LIGAMENTS.

MUSCLES

A number of muscles span multiple spinal segments and provide both mobility and considerable stability to the spine. The cervical and lumbosacral spines are endowed with muscles anteriorly, laterally, and posteriorly, whereas the thoracic spinal muscles are exclusively posterior. Abdominal, trunk, and limb muscles assist the intrinsic muscles of the spine in achieving a wide range of movements.

SPINAL STABILITY

The vertebral column, a modified segmented rod, is stabilized by both intrinsic (static) and extrinsic (dynamic) factors. Intrinsic (static) stabilizers include the intervertebral disks, the capsule of the facet joints, and various ligaments, particularly the anterior longitudinal and supraspinous ligaments and the ligamentum flavum. Extrinsic (dynamic) stabilizers include the paraspinal muscles (erector spinae, trunk, and abdominal muscles). Contraction of the trunk and abdominal muscles produces a rigid-walled cylinder in front of the spine. This transmits to the pelvis part of the forces generated on loading the spine and also acts as a lever that assists in reducing the load on the spine. The center of gravity falls either through or 1 cm anterior to the L4 vertebra. Shock absorption and vertical loads on the spine are attenuated by the balanced spinal curves, intervertebral disks, and paravertebral and trunk muscles.

SURFACE ANATOMY

Several landmarks can facilitate localizing specific spinal segments. The T2 vertebra is at the level of the top of the manubrium sterni. The apex of the spine of the scapula is even with the spine of T3, and the lower pole of the scapula is in line with the spine of T8. Although the position of the umbilicus varies with age, sex, obesity, and posture, it is generally on the same plane as the bottom of L3. A line connecting the upper border of the iliac crests crosses the midline at the level of L4, and a line drawn between the posterior superior iliac spines—beneath the sacral dimples, or “dimples of Venus”—crosses the second sacral segment.

FOCUS OF INITIAL HISTORY IS CRITICAL

It is crucial to focus the initial history on the one problem that accounts for more than 80% of neck and back symptoms: mechanical, spine-predominant (neck or low back) pain (Figure 8-7). Mechanical pain can be defined as symptoms arising from the irritation of a physical element or elements within the spine, predictably aggravated and relieved by specific movements and positions. It is the result of an anatomic malfunction unrelated to infection, neoplastic disease, systemic illness, or major trauma. An additional 10% of patients may present with symptoms of nerve root irritation with neurological, extremity-predominant radicular (arm or leg) pain.

FIGURE 8-7 CHART SHOWING PERCENTAGES OF MECHANICAL, NEUROLOGICAL, AND PATHOLOGICAL SPINE PAIN IN PATIENTS.

The overwhelming clinical probability that there is a purely structural pain generator involved in the patient’s neck or back pain makes it logical to begin the history by attempting to recognize a clearly defined mechanical pattern. Although spinal pain can arise from a myriad sources, the patient’s presenting symptoms are critical to understanding the clinical problem and should be obtained in a systematic and consistent manner.

ESSENTIAL INITIAL QUESTIONS

“Where exactly is your pain the worst?” The interrogation is precise, because the patient’s response must separate axial pain, along the spine, from pain primarily in the extremities. Although the pain may be referred into the arms or legs, mechanical pain usually remains most intense around the axial skeleton. In contrast, pain felt more strongly in the limbs than in the neck or back is usually radicular, representing direct nerve root irritation and typically traveling along the course of the involved roots.

Making identification even more problematic is the fact that mechanical neck or back pain is not necessarily felt mainly in the neck or back. Referred pain that originates in the neck can be most intense along the trapezius ridge; the interscapular region; at the occiput, sometimes with headache extending to the retroorbital area; and along the jaw line or the anterior chest (cervical angina). Referred pain that originates in the back may be perceived as most excruciating in the buttocks, groin, flanks, or trochanters.

“Is your pain constant or intermittent?” Over time, individual episodes of pain can blend into an unbroken, painful continuum. Some patients may be reluctant to admit that their pain is intermittent for fear of minimizing its importance, so how this question is framed is critical. The most effective way to introduce the question is to set the parameters before the patient is given the opportunity to respond. Acknowledge that you understand that the pain is severe and likely to recur before asking if there is ever a time when it is gone. Inquire specifically about such things as “the best time of day” or “the activity most likely to give you relief.”

“When your pain goes away, does it disappear completely?” The patient’s description of intermittent pain should be verified with this follow-up question, because patients may qualify their first response by saying that although the pain is much reduced, they are never totally pain free. Uncomplicated mechanical pain is typically intermittent. Without periods of total freedom from pain, decreased symptoms do not qualify as intermittent pain; the symptoms must be regarded as constant.

NECESSARY INFORMATION

Taking a history of spinal pain should be directed yet comprehensive. Appropriate evaluation requires a careful delineation of pain characteristics and associated features. A helpful mnemonic for characterizing spinal pain is OPQRSTU: O = onset; P = precipitating/ameliorating factors or prior episodes/treatment; Q = quality; R = radiation; S = severity; T = timing; and U = urinary or upper motor neuron symptoms.

Information about the onset, quality, and radiation of the symptoms may offer clues regarding the source of the pain. Identifying activities that heighten or diminish the pain may offer insight into the nature or location of a structural problem and may point to a possible treatment strategy. Because neck and back pain are frequently recurrent complaints, much can be learned from a detailed account of any previous episodes. These may forecast the characteristics of the present attack. Ascertain the effect of prior treatment. If the current situation is similar to the last one, what worked before may well work again. The reported intensity of the pain is typically of little diagnostic significance but does give a measure of the patient’s anguish and can serve as a baseline against which to measure future progress. Inquiries concerning changes in bowel or bladder function are mandatory with all patients. The history may uncover alterations in neurological status that must be investigated in the physical examination.

Finally, the history should establish the patient’s level of disability. The question, “Because of your pain, what can’t you do now that you were able to do before?” can elicit the degree of functional limitation. The intensity of treatment, indeed the need to treat at all, depends upon the answer.

NOTE: The lack of a defined mechanical response combined with a complaint of constant pain shifts the thrust of the questioning toward other nonstructural, potentially more serious etiologies. Questions should be directed at features associated with malignancy, infection, underlying visceral or systemic disease, psychosocial distress, or major injury. A group of important risk factors must be reviewed (see History and Physical Examination: Nonmechanical and Nonradicular Spinal Pain).

GENERAL EXAMINATION

Observation: The patient’s general appearance, posture, and level of distress should be noted at the start of the interview. Watching the patient’s gait, ease of movement, ability to sit without obvious discomfort, and facility in shifting from standing to sitting to a recumbent position provides valuable information.

With the patient suitably draped and the back exposed, inspect the skin over the spine for anatomic abnormalities, discoloration, superficial masses, and scars. Deformity or asymmetries can be recorded but should be considered significant only if they are unequivocal. Subtle alterations in alignment are rarely clinically important.

Palpation: Attempting to feel the bony prominences of the spine through the overlying skin, fat, fascia, and muscle is of limited usefulness. Depending on the size of the patient, it may be possible to approximate the locations of some of the vertebral spinous processes, particularly over the thoracic spine, but no other deep structures can be reliably identified. In the resting neutral position, the spinous processes of C7 and/or T1 are readily palpable in the midline at the base of the neck. Rarely in the lower lumbar spine it is possible to detect a step defect due to a high-grade spondylolisthesis (forward slip of one vertebra over the vertebra below), or an absent spinous process (spina bifida). Palpation can elicit areas of increased temperature, swelling, tenderness, or regions of painful, localized muscle tension. The relevance of these findings is usually determined by the history.

Movement: The normal range of spinal movement is a function of age, sex, body mass, and physical condition. Precise measurement is difficult, and wide variations in accepted normal values make the effort of little practical value. Of far greater clinical significance are the rhythm and symmetry of movement and the reproduction of the patient’s usual pain as reported in the history. Uninhibited spinal movement is a smooth segmental progression; interference produces a consistent, unilateral shift or a block to flexion or extension that forces compensatory movements in the adjacent spine or large joints. Rotation and side bending are coupled movements (one cannot be carried out without the other) and should be about equal on each side. Ask every patient who exhibits a reduction in range of movement or an alteration in spinal rhythm whether attempting to move reproduces their typical pain.

CERVICAL SPINE (Table 8-1)

Inspection: Assess the position of the head over the shoulders. Most patients with chronic neck complaints have a head-forward posture that is accentuated in sitting and noticeably reduced when the patient stands. In its middle position, the cervical spine should be in lordosis.

TABLE 8-1 EXAMINATION OF THE CERVICAL SPINE

An assessment of the shoulder should be part of every complete neck examination. Neck posture has a significant effect on the range of shoulder movement.

Movement: Assess cervical flexion, extension, rotation, and lateral bending, and ask the patient about any reproduction of the typical pain during movement. Assess shoulder range of motion.

Neurologic Examination

Irritative tests. Because of the mobility and multiple branches of the brachial plexus, the validity of irritative tests in the cervical spine to identify nerve root irritation is less certain than for those in the lower back. Rotating the head toward the painful side while forcing the neck into extension (Spurling maneuver, Figure 8-8) may reproduce the patient’s described arm pain, but a negative test does not rule out direct root involvement. Extending, abducting, and externally rotating the arm while extending the wrist and tilting the head to the contralateral side may also reproduce radicular symptoms. The intervening brachial plexus significantly diminishes the test’s sensitivity. Patients who experience a reduction in their arm pain by sitting with the hand on the affected side on top of their head (abduction relief sign, Figure 8-9) may be diminishing nerve root irritation by reducing tension on the lower plexus or lower cervical roots.

FIGURE 8-8 SPURLING MANEUVER.

FIGURE 8-9 ABDUCTION RELIEF SIGN (SHOULDER ABDUCTION SIGN).

Conductive tests. Motor testing is the most reliable physical measure of nerve conduction. In order, the most commonly involved nerve roots in the cervical spine are C6, C7, and C5. The examiner should gauge the strength of elbow flexion (C6, biceps), forward elevation of the arm (C6, anterior deltoid), elbow extension (C7, triceps), finger extension at the MCP joints (C7, extensor digitorum), and abduction of the arm (C5, central deltoid).

Reflex changes are identified by side-to-side comparison. The arms should be relaxed and supported. The biceps reflex is C5, C6; the brachioradialis reflex is C6; the triceps reflex is C7. Sensory testing is the least reliable investigation. The C6 dermatome includes the thumb, C7 covers the index and middle fingers, and C5 is best tested over the lateral deltoid.

Upper motor tests. Involvement of the spinal cord can produce upper motor findings in both the upper and lower extremities. In the cervical myelopathic patient, flicking the tip of the middle finger will cause a sudden involuntary flexion of the thumb and index finger (Hoffman sign; analogous to, but not nearly as specific as, the Babinski sign in the lower extremities). In the lower limbs, cervical cord compromise can produce hyperactive reflexes, sustained clonus, and an extensor plantar response with an up-going great toe and spreading of the other digits (Babinski sign).

THORACIC SPINE

LUMBAR SPINE (Table 8-2)

Range of Motion

Assess lumbar flexion by instructing the patient to bend forward at the waist and attempt to touch the toes. Normal lumbar flexion should involve progressive reversal of the lumbar curvature from lumbar lordosis in the standing position to flattening of the lordosis in mid flexion to flattening or even slight lumbar kyphosis at the end of full flexion (Figure 8-10). Assess lumbosacral extension by asking the patient to bend backward. Simultaneously supporting the low back with one hand and one shoulder with the other hand provides stability and permits you to help the patient into full extension. Assess lumbar lateral flexion (lateral bending) by asking the patient to bend to the right and to the left. Place your hands on both shoulders and, if necessary, provide gentle pressure to help the patient into lateral flexion and assess the patient’s response.

FIGURE 8-10 NORMAL THORACOLUMBAR FLEXION.

A, Resting lordosis. B, Reversal of lordosis to slight kyphosis.

Note any abnormalities of flexion, extension, and lateral bending. Most importantly, note whether these motions reproduce the patient’s pain.

An assessment of the hip joints should be part of a comprehensive low back examination. With the patient still standing, observe the pelvis from behind and identify the level of the iliac crests. Ask the patient to stand on one foot. Note whether the iliac crests remain level or whether the pelvis drops on the side opposite the standing leg. This pelvic “droop” (Trendelenburg sign) is a sensitive indicator of intrinsic hip disease and/or muscle weakness on the weight-bearing side. Repeat this test with the opposite leg.

Now ask the patient to lie supine and bring the hips into moderate flexion with the feet still on the exam table. Check for possible trochanteric bursitis by applying firm pressure to the lateral region of each trochanter, noting any tenderness. Next, check hip range of motion. Normal hip flexion brings the anterior thigh nearly to the chest. Return the hip and knee to 90° of flexion. Keeping the thigh perpendicular and the shin parallel to the examining table while testing hip rotation permits easy visualization of the arcs of movement. Hip external rotation is assessed by moving the ankle medially; hip internal rotation is assessed by moving the ankle laterally. Apply firm but gentle pressure to adequately assess range of motion. Question for the reproduction of typical pain.

NOTE: In patients with total hip replacements, be cautious in assessing hip range of motion. Avoid applying force when checking flexion and internal rotation, as this might dislocate the femoral component.

Pain originating from the hip joint itself is usually felt in the groin or medial thigh. Watch the patient’s face while you perform hip rotation; a change in facial expression may be your first indication that hip range of motion is painful.

Neurological Examination

Irritative tests. A passive straight leg raise (SLR) should reproduce the patient’s typical leg-predominant pain resulting from irritation of the roots of the sciatic nerve (L4, L5, S1, S2). With the patient lying supine, support the heel of the foot on the patient’s painful leg in the palm of your hand. With the patient’s knee extended, lift the leg. An increase in the patient’s reported leg pain constitutes a positive test (Figure 8-11). The location of the leg pain should be the same as that described in the history. The production of back pain is not a positive test and does not indicate nerve root irritation.

FIGURE 8-11 STRAIGHT LEG RAISE.

Many patients with severe sciatica cannot fully extend the knee on the affected side, and any attempt to do so will aggravate the characteristic leg pain. This constitutes a positive test. Patients demonstrating less nerve root irritability will allow increasing amounts of elevation. The higher the leg can be lifted, the less acute the radiculitis and therefore the less clinically significant the finding. But regardless of the point in the SLR at which the typical pain is produced, reproduction of the patient’s specific complaint is a positive finding. Variations on the technique—such as dorsiflexing the ankle, applying pressure to the popliteal fossa, or passively extending the knee with the hip already flexed at 90°—are all intended to create the same leg pain. Once the examiner has exacerbated the patient’s leg symptoms with one method, hurting the patient again in a different fashion seems unnecessary and unkind.

Occasionally, in cases of intense sciatica, performing an SLR on the unaffected leg will reproduce the typical pain on the symptomatic side. This form of crossed–straight leg test is the mark of an extremely irritable nerve root. It suggests a prolonged recovery and the likelihood that some type of intervention will be required.

A second type of crossed–straight leg test is far more ominous. In some patients, elevation of the affected leg produces not only the anticipated increase in the sciatic pain but also pain that radiates into the previously asymptomatic leg. This extremely rare finding can be the result of a large, centrally located disk herniation. Large, central protrusions are capable of compressing the entire cauda equina, including the lower sacral nerve roots (S3, S4, S5), which travel in the midline of the spinal canal and supply the sphincter muscles of the urinary bladder and the rectum. A massive central rupture of a lumbar disk (usually L3/L4 or L4/L5) can produce a cauda equina syndrome (CES) along with acute urinary retention with overflow and rectal incontinence. Decompression of an acute CES is a surgical emergency.

The femoral stretch test is comparable to the SLR but involves the roots of the femoral nerve (L2, L3, L4). With the patient lying prone, the examiner lifts the affected leg into extension at the hip (Figure 8-12). A positive response replicates the patient’s typical anterior thigh pain. The maneuver must aggravate the leg symptoms described in the patient’s history. Causing back pain is not a positive test.

FIGURE 8-12 FEMORAL STRETCH TEST.

Conduction tests. Over 80% of the root involvement in the lumbar spine is either L5 or S1. Motor testing for L5 should include a Trendelenburg test (hip abductors, discussed earlier), ankle dorsiflexion power, and great toe extension. The muscles to be tested for S1 are the gluteus maximus (hip extensors), ankle plantar flexors, and flexors of the great toe. Less frequently affected nerve roots are L3 and L4, which control quadriceps power (knee extension), and L2, which supplies the iliopsoas (hip flexors).

The ankle reflex is subtended by S1. The hamstring reflex is supplied equally by L5 and S1 and is only useful for differentiating between those two commonly involved roots when it is compared to the ankle reflex. The quadriceps reflex is primarily L4.

Sensory testing is of limited clinical value but may be comfortingly confirmatory. The L5 dermatome covers the lateral side of the lower leg and the dorsum of the foot to the great toe. S1 supplies the small toes, the sole of the foot, and the back of the calf. The medial calf is L4.

The one place where sensory testing plays an important role is the saddle area. The skin surrounding the anus, including the midline between the upper buttocks and the genitals, is supplied by the same sacral roots that control bowel and bladder function. Reduced sensitivity to light touch in this region may indicate disruption of the lower sacral nerves and the possibility of an acute CES. When a cauda equina syndrome is suspected, a rectal examination to assess anal sphincter tone is mandatory.

Upper motor tests. The spinal cord and the conus medullaris end at L2. No problem below that point can produce signs of upper motor damage. Some spinal cord lesions are capable of mimicking a single lumbar root lesion and can be completely missed without an upper motor examination. Finding sustained clonus or an extensor plantar response places the pathology at the cord level, above the lower lumbar spine.

CANCER, INFECTION, AND VERTEBRAL COMPRESSION

In patients with a history of cancer (excluding nonmelanoma skin cancer), recent unexplained weight loss, constant pain or disproportionate pain at night, age over 50, and failure to improve in 4 weeks increases the likelihood that cancer is the cause of the patient’s low back pain.

A history of cancer, especially diagnosed within the past 10 years, appears to be the most important risk factor. The presence of this risk factor increases the probability of cancer as a cause of low back pain from 0.7%—the probability of any individual having cancer-related low back pain—to 9.0%, the probability of this individual having cancer-related low back pain, now knowing there is a history of cancer. In the absence of a history of cancer, the presence of any one of the other risk factors in Table 8-1 only increases the probability of cancer to 1.2%.

Spinal pain accompanied by fever, a history of recent infection (especially of the skin and the genitourinary tract), intravenous drug use, or immunosuppression are important risk factors for possible spinal infection.

Spinal pain in elderly patients with a history of osteoporosis or of corticosteroid use clearly raises the suspicion of possible vertebral compression fracture.

The absence of any risk factors listed in Table 8-3 for cancer, infection, or vertebral compression fracture provides the clinician with extremely high reassurance that these conditions are not likely the cause of the patient’s low back pain.

INFLAMMATORY SPINAL PAIN: ANKYLOSING SPONDYLITIS AND OTHERS

Spinal involvement in the spondyloarthropathies (e.g., ankylosing spondylitis and spondylitis with reactive arthritis or inflammatory bowel disease) may involve the low back, thoracic spine, or neck and tends to occur early in the course of the disease. Initial symptoms are frequently vague and often overlooked.

Characteristic features of inflammatory spinal pain include initial symptoms present before 40 years of age, an insidious onset, significant morning stiffness, improvement of spinal pain with exercise and worsening with prolonged rest, and a duration longer than 3 months. These features, although not specific, strongly suggest inflammatory back pain and are quite different from typical mechanical low back pain.

If the clinical history suggests possible inflammatory low back pain, a more focused assessment of the sacroiliac joints and spine is appropriate (Table 8-4). Ask the patient to lie supine. Bring one hip and knee into flexion as you cross the leg over the opposite leg and rest the patient’s lateral malleolus on the opposite distal thigh (crossing the legs). Now, gently but firmly apply pressure to the medial aspect of the flexed knee, pushing it toward the exam table. This maneuver is called the FABER test, and it refers to the position of the hip in Flexion, ABduction, and External Rotation, stressing the ipsilateral sacroiliac joint (Figure 8-13). A positive FABER test requires reproduction of sacroiliac pain on the same side, felt in the upper inner buttock region rather than the lumbosacral junction, trochanter, or groin. This test may be difficult to interpret in patients with intrinsic hip disease, who may feel discomfort in the groin or gluteal region rather than the SI joint. Perform the FABER maneuver on the opposite side and compare.

TABLE 8-4 EXAMINATION OF THE SACROILIAC JOINTS AND SPINE

FIGURE 8-13 FABER TEST.

Next, gently but progressively press downward on both superior anterior iliac spines, driving the iliac wings posteriorly toward the exam table. This maneuver stresses both sacroiliac joints, and a positive compression test requires reproduction of the patient’s pain localized to the sacroiliac joint on one or both sides; induction of discomfort in other regions is not considered a positive test.

In patients whose history, examination, and imaging confirm the suspicion of a spondyloarthropathy, several spondylitis-specific measurements (Figure 8-14) are important to document initially, and in subsequent exams, to monitor disease progression and response to therapy:

FIGURE 8-14 SPONDYLITIS MEASUREMENTS.

A, Modified Schober test. B, Finger-to-floor distance. C, Finger-to-thigh distraction. D, Occiput-to-wall distance.

VISCERAL DISEASE

Although relatively uncommon, a variety of visceral disorders can refer pain to the spine. Pulmonary, pleural, cardiac, and pericardial diseases may manifest with neck and shoulder pain. Gastrointestinal, pancreatic, genitourinary, and atherosclerotic vascular disease (abdominal aortic aneurysm) may manifest with thoracic, flank, or low back pain. Inquiring about a significant pulmonary, cardiac, gastrointestinal, genitourinary, or vascular history may provide important clues to clarify the patient’s “spinal” complaints.

PSYCHOSOCIAL DISTRESS

When spinal pain persists, and serious disease has been ruled out, risk factors for underlying psychosocial barriers to recovery should be investigated. These include personal, social, and environmental factors (Table 8-5). Personal factors include attitudes, beliefs, emotions, and behaviors that the patient exhibits in response to spinal pain that are maladaptive and may prolong disability. Social and environmental factors pertain to how the patient interacts with his or her family, friends, and the workplace. Negative social relationships can impact pain perception and recovery. Psychological distress, the belief and fear that movement or activity will worsen the pain, and social isolation are other examples of psychosocial barriers that can delay recovery from spinal pain.

TABLE 8-5 PSYCHOSOCIAL RISK FACTORS FOR PERSISTENT SPINAL PAIN

Waddell’s behavioral signs were developed as a clinical assessment tool to help clinicians recognize important features of psychological distress and illness behaviors complicating low back pain. They must be viewed in conjunction with the history and cannot be used in isolation as proof of illness behavior. These signs are grouped into five categories of response:

The presence of significant superficial or nonanatomic tenderness, back pain in response to simulated axial loading or pelvic rotation, marked differences in response to supine and seated straight leg raising, nonphysiologic regional disturbances in motor or sensory function, and the presence of significant overreaction manifested by inappropriate guarding, limping, bracing, rubbing, grimacing, or sighing during the examination are important clinical signs and should not be ignored. The assessment of Waddell’s categories can be readily integrated into a rapid, organized, and sequential examination of the low back.

The presence of signs in three or more of Waddell’s categories may indicate significant psychosocial distress complicating the patient’s low back pain. Overinterpretation of behavioral signs must be avoided. Isolated behavioral signs should not be considered clinically significant. Furthermore, the presence of behavioral signs does not rule out an anatomic problem.

Waddell unequivocally states that the presence of signs in three or more categories “simply shows the health care provider that abnormal illness behavior may be present as a coping strategy and that other learned cognitive and behavioral patterns and psychological influences may need to be addressed to improve treatment outcome (Waddell et al., 1980).”

IMAGING

The use of imaging in patients with spinal pain should be judicious and discriminating. Decisions should be based on the presence of clinical features (risk factors) in the history and physical examination that significantly raise the suspicion of underlying serious conditions. Specific causes of spinal pain that justify imaging include cancer, infection, fracture, spondyloarthropathies, and visceral disease (see Table 8-3).

No evidence shows that routine imaging for mechanical spine-predominant or neurological extremity-predominant pain (~90% of all patients with spinal pain) improves patient outcomes. In fact, in the case of low back pain, unnecessary lumbar spine imaging has been associated with poorer patient outcomes. In the absence of risk factors suggesting an underlying serious condition, current evidence recommends against the routine use of imaging—plain film radiography, magnetic resonance imaging (MRI), or computerized tomography (CT)—for spinal pain.

ELECTRODIAGNOSTIC TESTS

Electrodiagnostic procedures are not a shortcut to diagnosis: they are a method of establishing physiological function. Evaluations may include peripheral nerve conduction velocity tests and/or electromyography to assess muscle activity. These investigations are most useful when they are used as part of a problem-solving approach to address a specific question arising from ambiguity in the clinical picture. They are best considered as an extension of a thorough physical examination and therefore unnecessary in patients with an unequivocal clinical presentation. Electrodiagnostic testing is not part of a standard presurgical evaluation.

ACUTE, UNCOMPLICATED, MECHANICAL NECK AND LOW BACK PAIN

Acute, uncomplicated, mechanical neck and low back pain accounts for the vast majority of spinal pain seen in clinical practice. The clinical history is important, and with a mechanical presentation in the absence of radicular or serious underlying conditions, the diagnosis of acute mechanical neck or low back pain is acceptable. A definitive anatomic diagnosis cannot be established in up to 85% of patients presenting with acute low back pain. Up to two thirds have resolution of their symptoms in 4 to 8 weeks, although recurrences are likely. The same is true for nontraumatic acute neck pain. Fortified by this information, the clinician is able to direct subsequent management efforts at reassurance and resumption of normal functional activity and avoid extensive and expensive, and frequently misleading, imaging studies.

CHRONIC NECK AND LOW BACK PAIN

Neck and low back pain persisting beyond 3 months despite conservative management develops in a minority of patients and represents a significant clinical and economic problem. Chronic neck and back pain patients consume the majority of all expenditures for spine-related pain. Important historical features may relate to the patient’s work, home, personal, and psychosocial history. Occupational risk factors associated with chronic neck and low back pain include physical stresses involved in manual labor, mental stress in both manual and office workers, and job-related stress due to lack of autonomy, lack of variation in workload, and lack of cooperation among workers. Pending litigation or disability determinations, marriage and family stress, drug or alcohol problems, and a history of anxiety, depression, or somatization are important contributing factors. These risk factors of chronic neck and low back pain identify patients who are at higher risk for persistent, disabling symptoms and permit earlier referral to multidisciplinary specialized centers (see Table 8-5).

CERVICAL DEGENERATIVE SPONDYLOSIS

Degenerative changes of the vertebral bodies, secondary to cervical degenerative disk disease or uncovertebral and facet joint osteoarthritis, are referred to as cervical spondylosis. It commonly occurs in older individuals and is related to the loss of integrity of the intervertebral disk, secondary osteoarthritic changes in the uncovertebral and apophyseal joints, and hypertrophy and redundancy of the ligamentum flavum. Symptoms often involve local neck pain, sometimes with referral to the shoulders or scapulae. Stiffness and crepitus on motion, positional pain, and sleep difficulty may also be present. Physical examination may reveal tenderness and spasm, usually of the lower cervical spine, and reduced cervical ROM. Symptoms and signs of radiculopathy—and, less commonly, myelopathy—may also be present. It is important to note that the presence or degree of cervical degenerative spondylosis on imaging does not necessarily correlate with the presence or severity of neck symptoms.

CERVICAL RADICULOPATHY AND MYELOPATHY

Neck pain combined with neurogenic upper-extremity pain strongly suggests cervical nerve root irritation. Pain may also radiate along the mid-scapular region. Far less common than uncomplicated mechanical neck pain, cervical radiculopathy usually results from disk herniation associated with facet and uncovertebral osteophytes causing mechanical or chemical irritation of the nerve root and its dural attachment as it enters the neural foramen. Physical examination may reveal variable tenderness, paravertebral muscle spasm, and reduced ROM of the cervical spine. Neurologic testing may reveal diminished reflexes, strength, or sensation in the affected root distribution. Prolonged radiculopathy can result in muscle atrophy. Radiating pain can often be reproduced or intensified with manual cervical compression or distraction maneuvers. Thoracic spine pain with radiation around the ribs likewise suggests thoracic radiculopathy.

Acute or chronic neck or thoracic pain may be accompanied by a progressive loss of neurologic function due to cord compression (myelopathy). Both the spinal pain itself and the symptoms of myelopathy may be quite subtle. Changes in bladder or bowel habits, impotence, gait unsteadiness, and loss of small motor control in the hands are important signs of myelopathy.

LUMBAR DEGENERATIVE SPONDYLOSIS

Degenerative changes in the vertebral bodies, secondary to lumbar degenerative disk disease and facet joint osteoarthritis, are commonly referred to as lumbar spondylosis. It typically occurs in older individuals and is related to intervertebral disk degeneration and osteoarthritic changes in the lower lumbosacral facet joints and sometimes to degenerative spondylolisthesis. Chronic low back pain with radiation to the buttocks is the most common symptom. The pain is mechanical in quality and is typically aggravated with activity and relieved by rest. Relatively brief morning stiffness, positional pain, and sleep difficulties may also be present. Physical examination often reveals tenderness to palpation in the lower lumbosacral spine and sacroiliac region. Lumbosacral movements may be painful and limited, especially forward flexion and extension. It is important to note that the presence or degree of lumbar degenerative spondylosis on imaging does not reliably correlate with the presence or severity of lumbosacral symptoms.

LUMBOSACRAL RADICULOPATHY

Low back pain combined with neurogenic lower extremity pain (sciatica) strongly suggests lumbosacral nerve root irritation. Pain may be abrupt or gradual in onset, and it typically radiates from the buttock to the posterior or posterolateral thigh or to the ankle or foot. There may be accompanying lower-extremity numbness, tingling, or weakness. The knee-flexed position, either supine or side-lying, often affords relief. Physical examination is remarkable for abnormal posture (list to one side), variable lumbosacral tenderness and muscle spasm, and reduced lumbosacral ROM. Nerve stretch signs (e.g., SLR, femoral stretch sign) indicating lumbosacral root irritation are frequently present. Neurologic testing may indicate diminished reflexes, strength, or sensation in the affected root distribution. Almost 85% of lumbosacral disk herniations involve the L4/L5 (L5 nerve root) or L5/S1 (S1 nerve root) level. In most cases symptoms resolve without the need for surgery, although symptoms persist longer than typical mechanical low back pain.

Acute, severe low back pain with bilateral sciatica, saddle anesthesia, and recent-onset urinary dysfunction (retention, overflow incontinence) and/or loss of rectal sphincter tone strongly suggests a cauda equina syndrome.

DEGENERATIVE LUMBAR SPINAL STENOSIS

Degenerative lumbar spinal stenosis is a relatively common cause of neurogenic lower-extremity pain in older individuals. Varying combinations of degenerative disk disease with loss of disk height, redundancy and hypertrophy of the ligamentum flavum, and occasionally degenerative spondylolisthesis lead to narrowing of the spinal canal with lateral recess or foraminal stenosis at multiple levels (Figure 8-15). Increased mechanical load on the facet joints combine with osteoarthritic changes and osteophyte formation. The onset of symptoms is typically insidious. The principal symptom is pain with tingling or numbness in one or both legs with standing, ambulation or spinal extension that is relieved by sitting or forward spinal flexion, but there may also be associated low back pain. Freedom from or improvement of symptoms during exercise in a flexed position (leaning on a grocery cart, walking uphill, bicycling) helps differentiate degenerative spinal stenosis from vascular claudication. Physical findings can include posterior thigh pain and transient motor weakness after 90 seconds of forced spinal extension, a wide-based gait, abnormal motor or sensory testing, and normal lower-extremity pulses. The physical examination is typically normal with the patient at rest, and the diagnosis is made primarily on the patient’s history. Differential diagnosis includes hip disease, trochanteric bursitis, and peripheral neuropathy.

FIGURE 8-15 AXIAL LUMBAR COMPUTED TOMOGRAPHIC SCAN: DEGENERATIVE SPINAL STENOSIS.

(Discovertebral degenerative changes, facet joint osteoarthritis, and ligamentum flavum hypertrophy).

WHIPLASH

It is important to understand that whiplash is only a mechanism of injury and not a description of any resulting structural damage. There is no clinical diagnosis of whiplash. The whiplash movement of the cervical spine most frequently occurs secondary to motor vehicle collisions or athletic injury. Acceleration and deceleration forces may result in injury to the intervertebral disks, apophyseal joints, and paraspinal soft tissues of the cervical spine. Patients may experience cervical discomfort with referral to shoulders or to the interscapular region, symptoms similar to mechanical neck pain. Neck symptoms without functional limitations are classified as Whiplash Associated Disorder I (WAD I); when there are associated functional limitations, as WAD II; as WAD III when radicular symptoms are present; and WAD IV when the injury results in cervical spine fracture or dislocation. Physical examination findings in WAD I and WAD II are similar to those found with mechanical neck pain, and typical findings in cervical radiculopathy have been described previously. When WAD IV is suspected, patients should be referred for appropriate orthopedic assessment.

SPINAL FRACTURE

The evaluation of spinal pain immediately following major trauma, motor vehicle collisions, athletic injury, or worksite injury primarily involves the identification of fracture or dislocation. The clinical setting and initial screening history should identify such patients, and an appropriate orthopedic assessment can be initiated.

Acute thoracic or lumbar spine pain associated with lesser trauma or injury—such as a minor fall, twisting, or heavy lifting in an older individual—raises the possibility of an osteoporotic fracture.

THORACIC COMPRESSION FRACTURE

Osteoporotic compression fracture of a mid thoracic to lower thoracic vertebra is one of the common causes of acute thoracic spine pain in the elderly. Risk factors include advanced age, female sex, personal or family history of fracture, cigarette smoking, low body weight, estrogen or testosterone deficiency, and corticosteroid use. Acute, severe spine pain, especially when accompanied by radiation bilaterally around the rib cage, strongly suggests a compression fracture. Focal spinal tenderness to palpation or gentle percussion, in the absence of neurologic symptoms or signs of malignancy or infection, increases the likelihood of a possible compression fracture.

INFLAMMATORY SPINAL PAIN

Spinal involvement in the spondyloarthropathies (e.g., ankylosing spondylitis, reactive arthritis, and spondylitis of inflammatory bowel disease) may involve the low back, thoracic spine, or neck and tends to occur early in the course of the disease. Initial symptoms are frequently vague and often overlooked. Characteristic features of inflammatory spondyloarthropathies include age less than 40 years, an insidious onset, significant morning stiffness, improvement of spinal pain with exercise and worsening with prolonged rest, awakening in the second half of the night with spinal pain, and a symptom duration of longer than 3 months. Although not specific, these features strongly suggest inflammatory back pain and are quite different from mechanical low back pain. The presence of SI joint pain and tenderness, limited spinal movements, and reduced chest expansion should prompt further investigation, most importantly an anteroposterior pelvic radiograph (Ferguson view) to check for radiographic sacroiliitis (Figure 8-16).

FIGURE 8-16 ANTEROPOSTERIOR RADIOGRAPH OF THE PELVIS.

A 20° caudal tube angle showing bilateral sacroiliitis.

Spinal involvement in rheumatoid arthritis is confined to the neck and tends to occur late in the course of erosive disease. Inflammatory synovitis may cause progressive laxity of the ligaments between C1 and C2, resulting in atlantoaxial instability, and/or lower cervical intervertebral instability, resulting in subaxial subluxation. Despite the seriousness of these lesions, there may be little or no neck pain.