Male predominance	Spondyloarthropathies Vertebral osteomyelitis Benign and malignant neoplasms Paget disease Retroperitoneal fibrosis Peptic ulcer disease Work-related mechanical disorders
Female predominance	Polymyalgia rheumatica Fibromyalgia Osteoporosis Parathyroid disease

Data from Klippel JH, Dieppe PA: Rheumatology, vol 1-2, ed 2, London, 1998, Mosby.

Other than the common cold, back pain is the most prevalent human affliction. As stated earlier, most patients have a mechanical cause (muscle strain or annular tear) for their back pain and do not have an underlying, serious, systemic medical illness.

Even if treatment involves only a localized part of the lumbar spine, in each case, the lumbar spine has to be considered as a functional unit consisting of bones, ligaments, intervertebral discs, muscles, and all other soft tissues. Because of their central location, spinal elements represent the focal point for the equilibrium of the body. Because of the many connections and relations, spinal changes influence some organs directly, and the functional equilibrium of the spine depends on the efficient performance of other organs.

TABLE 8-1 LUMBAR SPINE CROSS-REFERENCE TABLE BY ASSESSMENT PROCEDURE

TABLE 8-2 LUMBAR SPINE CROSS-REFERENCE TABLE BY SYNDROME OR TISSUE

Cord tumor	Bragard sign Lasègue test Milgram test Straight-leg-raising test
Denervation	Matchstick test Skin pinch test
Dural adhesions	Bechterew sitting test Fajersztajn test Lasègue test Straight-leg-raising test
Femoral nerve	Ely sign Femoral nerve traction test Hyperextension test Prone knee-bending test
Fracture	Minor sign Spinal percussion test
Hamstring spasm	Lewin standing test
Hip lesion	Ely sign Sign of the buttock
Intervertebral disc syndrome	Antalgia sign Bechterew sitting test Bilateral leg-lowering test Bragard sign Cox sign Double-leg-raise test Fajersztajn test Heel/toe walk test Kemp test Lasègue rebound test Lasègue test Lewin punch test Lewin snuff test Lewin supine test Matchstick test Milgram test Minor sign Neri sign Skin pinch test Spinal percussion test Straight-leg-raising test
Intervertebral foramen encroachment	Bechterew sitting test Bilateral leg-lowering test Lasègue test
L2–L3–L4	Femoral nerve traction test Hyperextension test Prone knee-bending test
Lower extremity joints	Quick test
Mechanical lower back	Bilateral leg-lowering test Demianoff sign Double-leg-raise test Kemp test Lasègue test Nachlas test Neri sign Schober test Sign of the buttock Skin pinch test Spinal percussion test
Meningitis	Kernig/Brudzinski sign
Myofascitis	Lewin supine test Skin pinch test
Sacroiliac lesion	Lasègue test Lewin supine test Mennell sign Minor sign Nachlas test Neri sign
Sciatica	Bechterew sitting test Bragard sign Deyerle sign Fajersztajn test Heel/toe walk test Lasègue sitting test Lasègue test Lewin snuff test Lewin standing test Lewin supine test Sicard sign Turyn sign Vanzetti sign
Spinal neuropathy	Bowstring sign Bragard sign Ely sign Femoral nerve traction test Heel/toe walk test Kemp test Lasègue differential sign Lasègue sitting test Sicard sign
Sprain	Double-leg-raise test Spinal percussion test
Subluxation	Bechterew sitting test Nachlas test

The spine contributes to many mutual relationships within the total body. With its equilibrium (statics), the spine exerts, influences, and receives forces (dynamics), all of which are interwoven with the far-reaching chain of motion (kinetics). In addition, the spine is able to exercise considerable influence on neighboring structures, as well as on remote organs. This influence is its action on nerves and blood vessels. To a considerable degree, this complicated system depends on the metabolism, the mineral metabolism of the bones, and the nutrition of the bradytrophic ligamentous and disc tissues. Improper function of the endocrine glands also affects the spine.

During fetal development, the spine may be exposed to many influences, such as drug-induced malformations, lack of oxygen, or radiation.

Occupational and daily-living stresses, as well as traumatic influences, may combine to have an unfavorable effect when coupled with the aging process, which has a marked effect on the disc apparatus and the bony substance. More resources for the diagnosis and treatment of spinal diseases are available today than previously.

Degeneration of posture during early years, lack of exercise, physical weakness, and degenerative changes in later life have taken on a serious social significance for the cultures of industrialized nations.

The spine is an intricate and interesting mechanical structure. The spine’s functions are mechanical, and it is well suited for serving its basic mechanical roles. The materials used to execute the design are appropriate for enhancing these functions. The spine must transfer loads from the trunk to the pelvis, must allow for physiologic motion, and must protect the spinal cord from damage. When a proper appreciation of normal anatomy and mechanics has been gained, the pathophysiologic features of the diseased or deformed spine become clear.

The lumbar spine is designed to withstand loading and to provide truncal mobility. The primary plane of motion is during flexionextension, although axial rotation at the L5 level is significant. This rotation in the lower lumbar spine is particularly important, considering that the annulus fails and tears with torsional forces. Coupling in the lumbar spine is the opposite of cervical and thoracic spine coupling. The spinous processes move toward the concavity of the curve in physiologic lateral flexion.

Optimal spinal mobility in relation to age is difficult to pin down. The only generalization that can be made is that spinal mobility is probably greatest during adolescence and early adulthood. This tendency is significant when planning treatment and in determining prognoses.

The anatomic structures of the lumbosacral spine receive specific types of sensory innervation that are associated with distinct qualities of pain (Table 8-6).

TABLE 8-6 SUMMARY OF THE CHARACTERISTICS OF LOW BACK PAIN OF VARIOUS ORIGINS

ESSENTIAL ANATOMY

The lumbar spine consists of five lumbar vertebrae, numbered L1 to L5, followed by five fused sacral bodies that form the sacrum and the coccyx. The alignment of the lumbar spine generally has a lordotic contour. The normal lordosis is 30 to 50 degrees (apex L3) in a standing person.

ESSENTIAL MOTION ASSESSMENT

Range-of-motion findings are most helpful in pinpointing a vertebral structure that may be compromised in the lumbar spine. Pain at an early point in the extension of the lumbar spine suggests an inflamed posterior joint or pars disease. Painful lumbar flexion in the early-to-middle range connotes a faulty disc mechanism or muscular stain. Because the terminal range of flexion causes the facet joint capsule to stretch, a pain response at this point may indicate a posterior joint sprain.

Patients with acute spasm or significant trauma often have multidirectional complaints and severe limitation of motion in all planes. Therefore, range-of-motion testing may be initially inconclusive as to the severity of the injury.

To assess the contribution made to flexion by the lumbar spine, the examiner should mark the spine at the lumbosacral junction and then 10 cm above and 5 cm below this point. On forward flexion, the distance between the two upper marks should increase by approximately 4 cm, the distance between the lower two remaining unaltered (Figs. 8-1 to 8-4).

FIG. 8-1

FIG. 8-2 The patient flexes forward, and the angle of both inclinometers is recorded. The sacral inclination is subtracted from the T12 inclination to obtain the lumbar flexion angle.

FIG. 8-3 Extension is limited to 35 degrees in the lumbar spine. The patient extends the lumbar spine, and the angles of both instruments are recorded. The sacral inclination angle is subtracted from the T12 inclination angle to obtain the lumbar extension angle.

FIG. 8-4 Both instruments are zeroed at the superior aspect of the sacrum, in the coronal plane (A). The patient laterally flexes the lumbar spine to one side, and the inclinations of both instruments are recorded (B). The sacral angle is subtracted from the T12 angle to obtain the lumbar lateral flexion angle. The procedure is repeated for the range of motion to the opposite side. Lateral flexion of 20 degrees or less to either side is an impairment of the lumbar spine in the activities of daily living.

ESSENTIAL MUSCLE FUNCTION ASSESSMENT

The erector spinae consist of a minor portion (the spinalis) and two major portions (the longissimus and iliocostalis). The spinalis connects spinous processes, and the longissimus and iliocostalis connect homologous portions of the costal and transverse elements of the lumbar, thoracic, and cervical vertebrae and skull.

Useful in screening is muscle testing of the legs, which measures strength on a 5-point scale for extension and flexion (knee), abduction and adduction (hip), and eversion and inversion, as well as dorsiflexion and plantar flexion (foot) (Table 8-7).

TABLE 8-7 LUMBAR RADICULAR SYNDROMES

For patients in whom the objective findings do not match the subjective complaints, close observation helps identify the inconsistencies (Table 8-8). A finding of three or more of the five signs of the Waddell index is clinically significant. Isolated positive signs are ignored.

TABLE 8-8 NONORGANIC PHYSICAL SIGNS INDICATING ILLNESS BEHAVIOR

	Physical Disease/Normal Illness Behavior	Abnormal Illness Behavior
Symptoms
Pain	Anatomic distribution	Whole leg pain
		Tailbone pain
Numbness	Dermatomal	Whole leg numbness
Weakness	Myotomal	Whole leg giving way
Time pattern	Varies with time and activity	Never free of pain
Response to treatment	Variable benefit	Intolerance of treatments
		Emergency admissions to hospital
Signs
Tenderness	Anatomic distribution	Superficial
		Widespread nonanatomic
Axial loading	No lumbar pain	Lumbar pain
Simulated rotation	No lumbar pain	Lumbar pain
Straight leg raising	Limited on distraction	Improves with distraction
Sensory	Dermatomal	Regional
Motor	Myotomal	Regional, jerky, giving way

From Demeter SL, Andersson GBJ, Smith GM: Disability evaluation, St Louis, 1996, Mosby.

The iliacus arises from the iliac fossa and joins the psoas under the inguinal ligament. The iliacus then crosses the hip joint capsule and inserts into the lesser trochanter of the femur. These muscles flex the lumbar spine and bend it toward the same side. The quadratus lumborum, which lies lateral to the vertebral column, arises from the posterior part of the iliac crest and iliolumbar ligament and inserts into the twelfth rib and the tips of the transverse processes of the upper four lumbar vertebrae. This muscle fixes the diaphragm during inspiration and bends the trunk toward the same side when it acts alone (Figs. 8-5 to 8-7).

FIG. 8-5 The patient is lying prone on the examination table. The patient then extends the trunk.

FIG. 8-6 Lateral flexion of the trunk requires a combination of lateral flexion and hip abduction. The patient is side lying, with the head, upper trunk, pelvis, and lower extremities in a straight line. During the test, the patient laterally flexes the trunk away from the examination table.

FIG. 8-7 Raising the trunk obliquely forward combines trunk flexion and rotation. The patient is supine on the examination table, and the legs are supported by the examiner.

ESSENTIAL IMAGING

A variety of radiographic views can be taken when the lumbosacral region is evaluated. The standard views consist of the anteroposterior (AP), lateral, oblique, and either a frontal or a lateral lumbosacral spot.

ANTALGIA SIGN

Assessment for Posterolateral, Posteromedial, and Posterocentral Intervertebral Disc Protrusion

Comment

Two major types of low back abnormalities center on the intervertebral disc: acute impairment from herniated discs and chronic impairment from degenerative disc disease (Table 8-9).

TABLE 8-9 LUMBAR DISC SYNDROMES

	Lumbar Herniated Nucleus Pulposus	Degenerative Disc Disease
Physical examination findings	Back or leg pain Sciatic nerve tension signs: Positive straight leg raise less than 60 degrees Positive Bragard sign Positive bowstring sign Positive Bechterew test Painful arc of lumbar flexion, extension, or both True nerve root signs: Radiculopathy Motor or sensory deficit Paresthesias Diminished or absent deep-tendon reflexes Possible antalgia, muscle spasm, instability

Morning stiffness

Lumbopelvic hypomobility

Pain in lumbar flexion

History consistent with spinal degeneration

X-ray findings

Need to rule out organic abnormality

Hypolordosis secondary to muscle spasm

Possible loss of intervertebral disc height

Possible diagnosis of degenerative arthritis

Radiologic signs in acute exacerbation

Spur formation

Loss of intervertebral disc height

Discogenic spondylosis

Compatible findings on CT or MRI scans

CT, Computed tomography; MRI, magnetic resonance imaging.

Adapted from Brier SR: Primary care orthopedics, St Louis, 1999, Mosby.

ORTHOPEDIC GAMUT 8-2 DISC INJURIES

Definitions of disc injuries are as follows:

1. Disc protrusion is present when nuclear material does not extend beyond the annulus in a contained herniated nucleus pulposus.

2. Disc extrusion is a focal herniation contained by the posterior longitudinal ligament that extends into the spinal canal.

3. Sequestered disc is a free fragment that has broken off or through the annular peripheral fibers in the vertebral canal (prolapsed).

A disc may protrude lateral to a nerve root, medial to a nerve root, under a nerve root, or central to the nerve root.

PROCEDURE

• When the disc protrudes lateral to the nerve root, the patient assumes an antalgic lean away from the side of the disc lesion or pain (Fig. 8-8).

• When the disc protrudes medial to the nerve root, the patient assumes an antalgic lean into the side of the disc lesion or pain (Fig. 8-9).

• With a central disc lesion, the patient assumes a flexed posture of the lumbar spine, with or without leaning to either side (Fig. 8-10).

• With protrusion under the nerve root, the patient may not lean at all.

FIG. 8-8

FIG. 8-9

FIG. 8-10 With a central disc lesion, the patient assumes a flexed posture of the lumbar spine, with or without leaning to either side.

CLINICAL PEARL

If the antalgia is not readily apparent in a static posture, it will appear with forward flexion of the trunk. If a disc protrusion exists, even in the mildest degree, trunk flexion exerts enough pressure to irritate the inflamed muscle or to stretch neural structures over the bulging disc. The antalgia is manifested at this point. Patients with lower back pain might stiffen the trunk and pelvis and hyperextend the knees in an effort to decrease the number of degrees of freedom.

BECHTEREW SITTING TEST

Assessment for Sciatica, Intervertebral Disc Lesion, Vertebral Exostoses, Dural Sleeve Adhesions, Muscular Spasm, or Vertebral Subluxation

PROCEDURE

• While in a seated position, the patient attempts to extend each leg, one at a time.

• The examiner restricts the patient’s attempts at hip flexion with downward pressure on the thigh (Fig. 8-11).

• This extension is followed by an attempt to extend both legs.

• The test is positive if backache or sciatic pain is increased or if the maneuver is impossible.

• In disc involvement, extending both legs will usually increase the spinal and sciatic discomfort.

• A positive test indicates sciatica, a disc lesion, exostoses, adhesions, spasm, or subluxation.

FIG. 8-11

CLINICAL PEARL

Simple flattening or even reversing the lumbar curve is often not associated with radicular pain. The pain is localized in the lower lumbar spine, and any movement of the spine accentuates the pain. In these instances, the prime pathologic feature is sprain of an intervertebral joint rather than root irritation.

BILATERAL LEG-LOWERING TEST

Assessment for Mechanical Lumbosacral Lesion, Intervertebral Disc Lesion, or Vertebral Exostoses

PROCEDURE

• The patient lowers the straightened legs from a 90-degree angle to a 45-degree angle (Fig. 8-12).

• The test is positive if the legs drop or if the move produces pain.

• A positive test indicates lumbosacral involvement, disc lesions, or exostoses.

FIG. 8-12

CLINICAL PEARL

Because of the presence of the nociceptive nerve ending within the annulus fibrosus of the disc, annular tears can cause pain in the lower back, buttocks, sacroiliac region, and lower extremity. This pain can occur without nerve compression by a disc protrusion. Disc protrusion that does not compress the nerve root can cause an inflammatory response and secondary radiculitis by chemically induced inflammatory neural pain.

BOWSTRING SIGN

Assessment for Lumbar Nerve Root Compression

ORTHOPEDIC GAMUT 8-3 LUMBOSACRAL NERVE ROOTS

After leaving the dural sac, the lumbosacral nerve roots run caudally and laterally in the direction of departure from the spinal canal:

1. The fourth lumbar root (L4) leaves the dural sac slightly caudal of the intervertebral disc between the third and fourth lumbar vertebrae (third lumbar disc).

2. The fifth lumbar root (L5) leaves the dural sac near the level of the fourth lumbar disc.

3. The first sacral root (S1) leaves the dural sac medial of S1 and slightly below the level of the L5 disc.

ORTHOPEDIC GAMUT 8-4 WALLERIAN DEGENERATION SEQUENCE

• When axonal continuity is disrupted by mechanical compression or nerve trunk ischemia:

• Axons distal to the stump divide finely and begin to degenerate.

• At the same time, the myelin sheaths that have lost axons begin to break down.

• Wallerian degeneration occurs peripheral to the site of compression in the anterior root and central to this site (i.e., toward the spinal cord) in the posterior root when the cauda equina or nerve root is compressed by a herniated intervertebral disc or spinal canal stenosis.

• Nerve roots have a regenerative capacity similar to that of peripheral nerves.

• While regeneration of the anterior root approximates that of peripheral nerves, recovery of sensation presents problems in the posterior root because degeneration extends into the spinal cord.

PROCEDURE

• With the patient in the supine position, the examiner moves the patient’s leg until it is above the examiner’s shoulder.

• At this point, firm pressure should be exerted on the hamstring muscles (Fig. 8-13).

• If pain is not elicited, pressure is applied to the popliteal fossa.

• Pain in the lumbar region or radiculopathy is a positive sign for nerve root compression.

FIG. 8-13

CLINICAL PEARL

Nerve roots must change their lengths depending on the degree of flexion, extension, lateral flexion, and rotation of the lumbar spine. Lumbar nerve roots that are limited in motion by fibrosis of either intraspinal or extraspinal origin will create traction on the nerve root complex, causing ischemia and secondary neural dysfunction.

BRAGARD SIGN

Assessment for Sciatic Neuritis, Spinal Cord Tumor, Intervertebral Disc Lesions, and Spinal Nerve Irritation

PROCEDURE

• If the Lasègue test or the straight-leg-raising test is positive, the leg is lowered below the point of discomfort, and the foot is sharply dorsiflexed (Fig. 8-14).

• The sign is present if pain is increased.

• The presence of the sign is a finding associated with sciatic neuritis, spinal cord tumors, intervertebral disc lesions, and spinal nerve irritations.

FIG. 8-14

CLINICAL PEARL

Either the Bragard sign or the Hyndman sign (for neck flexion movement) must be accomplished as a finishing maneuver in any positive straight-leg-raising test. Pain that increases during neck flexion, ankle dorsiflexion, or both indicates an inflamed nerve root. Pain that does not increase with these maneuvers may indicate a problem in the hamstring area or in the lumbosacral or sacroiliac joints.

COX SIGN

Assessment for Prolapse of Intervertebral Disc Nucleus

Comment

Several maneuvers tighten the sciatic nerve and compress an inflamed nerve root against a herniated lumbar disc. With the straight-leg-raising tests, the L5 and S1 nerve roots move several millimeters at the level of the foramen. The L4 nerve root moves a smaller distance, and the proximal roots show little motion. The straight-leg-raising tests are most important and valuable for detecting lesions of the L5 and S1 nerve roots. Young patients with herniated discs have marked propensities for positive straight-leg-raising tests. Although the test itself is not pathognomonic, a negative test rules out the possibility of a herniated disc. After age 30, a negative straight-leg-raising test no longer precludes this diagnosis. Lumbosacral transitional vertebrae complicate this further (Table 8-10).

TABLE 8-10 CASTELLVI CLASSIFICATION OF LUMBOSACRAL TRANSITIONAL VERTEBRA

• Type I: dysplastic transverse process

• Type Ia (unilateral) height >19 mm

• Type Ib (bilateral) height >19 mm

• Type I is not considered a true lumbosacral transitional vertebra because no articulation with the sacrum is present

• Type II: incomplete lumbarization/sacralization

• Type IIa enlarged transverse process with unilateral pseudoarthrosis with the adjacent sacral ala

• Type IIb enlarged transverse process with bilateral pseudoarthrosis with the adjacent sacral ala

• Type III: complete lumbarization/sacralization

• Type IIIa enlarged transverse process that has unilateral complete fusion with the adjacent sacral ala

• Type IIIb enlarged transverse process that has bilateral complete fusion with the adjacent sacral ala

• Type IV: mixed (type IIa on one side and type IIIa on the other)

PROCEDURE

• Cox sign occurs during straight leg raising when the pelvis rises from the table instead of the hip flexing (Fig. 8-15).

• Cox sign is present when patients have a prolapse of the nucleus into the intervertebral foramen.

FIG. 8-15

CLINICAL PEARL

Cox sign is a consistent finding associated with disc prolapse. The sign is often overlooked in the patient’s pain presentation. A false-negative test result may occur if the examiner does not observe the movements of the buttocks on the affected side. The sign is present the moment hip flexion motion is locked and the buttock rises from the examination table.

DEMIANOFF SIGN

PROCEDURE

• While the patient is in the supine position, the examiner performs a straight-leg-raising test with either leg.

• The sign is present when this action produces a pain in the lumbar region.

• This pain prevents the patient from raising the leg high enough to form an angle between the examination table and the leg of 15 degrees or more (Fig. 8-16).

• The sign differentiates pain that originates in the sacrolumbalis muscles from lumbar pain of any other origin.

• A positive test demonstrates that the pain is caused by the stretching of the sacrolumbalis (iliocostalis lumborum).

FIG. 8-16

CLINICAL PEARL

Demianoff sign is clearly separate from Cox sign. Demianoff sign involves production of lower back pain, which prevents further raising of the leg. Sciatica is absent. Cox sign is present when the pelvis is locked, which prevents further elevation of the leg because of increasing sciatica.

DEYERLE SIGN

Assessment for Sciatic Nerve Irritation

Comment

Occasionally, L4 lesions may also cause similar symptoms and signs. The phase of degeneration or spondylosis often determines the level of intervention (Table 8-11).

TABLE 8-11 OVERVIEW OF SCHEME OF TREATMENT RELATIVE TO THE PHASE OF SPONDYLOSIS

Phase	Lesion	Treatment
Dysfunction	Facet joint Sacroiliac joint Myofascial syndromes Disc herniation

Mobilization, manipulation, injection

Contract stretching, injection

Epidural injection, discectomy

Unstable

Disc herniation

Segmental instability

Lateral stenosis

Central stenosis

Degenerative olisthesis

Isthmic olisthesis

Epidural injection, discectomy

Injection, fusion

Nerve root block, decompression, fusion

Epidural injection, decompression, fusion

Stabilization

Disc herniation

Lateral stenosis

Central stenosis

Degenerative olisthesis

Isthmic olisthesis

Epidural injection, discectomy

Nerve root block, decompression

Epidural injection, decompression

Epidural injection, decompression, rarely fusion

From Kirkaldy WH: Managing low back pain, ed 4, Philadelphia 1999, Churchill Livingstone.

PROCEDURE

• While the patient is seated, the affected leg is passively extended at the knee until pain is reproduced.

• The knee is then slightly flexed while strong pressure is applied by the examiner into the popliteal fossa (Fig. 8-17).

• The sign is present if this pressure increases radicular symptoms.

• The sign demonstrates irritation of the sciatic nerve above the knee.

• This irritation is caused by stretching the nerve over an abnormal mechanical obstruction.

FIG. 8-17

CLINICAL PEARL

Deyerle sign is a variation of the Lasègue sitting test. The sign demonstrates the effects of inflammation or partial denervation (neural compression) in the sciatic distribution. The pain response may be caused by myalgic hyperalgesia as a response to denervation hypersensitivity.

DOUBLE-LEG-RAISE TEST

ALSO KNOWN AS BILATERAL STRAIGHT-LEG-RAISING TEST

Assessment for Lumbosacral Joint Involvement

PROCEDURE

• While the patient is supine, the examiner performs a straightleg-raising test on each of the patient’s lower extremities, noting the angle at which the pain is produced.

• Next, both lower limbs are raised together.

• If pain is produced at an earlier angle by raising both legs together, the test is positive (Fig. 8-18).

• In the presence of disc disease with resulting vertebral instability, the double-leg-raising movement will cause pain in the lumbar area.

• The test is specific and highly accurate for lumbosacral joint involvement.

FIG. 8-18

CLINICAL PEARL

A typical cases of disc prolapse are common. A definite history of injury or strain is often lacking. The pain may begin gradually rather than suddenly, and the symptoms may be confined to the back and never radiate down the leg. On the other hand, the pain is sometimes felt predominantly in the limb and is scarcely perceptible in the back.

ELY SIGN

ELY HEEL-TO-BUTTOCK TEST

Assessment for Lumbar Radicular or Femoral Nerve Inflammation

Comment

The size of the lumbar vertebral canal ranges from 12 to 20 mm in its AP dimension at the mid sagittal plane and 18 to 27 mm in its transverse diameter. Stenosis has been defined as a narrowing below the lowest value of the range of normal (Table 8-12).

TABLE 8-12 DIMENSIONS OF THE LUMBAR VERTEBRAL FORAMINA (VERTEBRAL CANAL)^*

Dimension	Size (Range)^†
Anteroposterior (in midsagittal plane)	12–20 mm
Transverse (interpedicular distance)	18–27 mm

‡ A typical vertebral foramen is rather triangular (trefoil) in shape. However, the upper lumbar vertebral foramina are more rounded than the lower lumbar foramina. L1 is the most rounded, and each succeeding lumbar vertebra becomes increasingly triangular, with L5 the most dramatically trefoil of all. From Dommisse GF, Louw JA: Anatomy of the lumbar spine. In Floman Y, editor: Disorders of the lumbar spine, Rockville, Md, and Tel Aviv, Israel, 1990, Aspen and Freund Publishing House.

* Dimensions below the lowest value indicate spinal (vertebral) canal stenosis.

† Dimensions of lumbar vertebral foramina are usually smaller than those of the cervical region but larger than those of the thoracic region. From Cramer GD, Darby SA: Basic and clinical anatomy of the spine, spinal cord, and ANS, St Louis, 1995, Mosby.

ORTHOPEDIC GAMUT 8-8 COMPLEX REGIONAL PAIN SYNDROME DIAGNOSTIC CRITERIA (INTERNATIONAL ASSOCIATION FOR THE STUDY OF PAIN)

1. Complex regional pain syndrome type I (CRPS-I) is a syndrome that develops after an initiating noxious event.

2. Spontaneous pain or allodynia/hyperalgesia occurs, is not limited to the territory of a single peripheral nerve, and is disproportionate to the inciting event.

3. Evidence exists or has existed of edema, skin blood flow abnormality, or abnormal sudomotor activity in the region of the pain since the inciting event.

4. This diagnosis is excluded by the existence of conditions that would otherwise account for the degree of pain and dysfunction.

5. For the diagnosis of CRPS-I, criteria 2 through 4 must be fulfilled.

PROCEDURE

• The patient is prone, with the toes hanging over the edge of the table and legs relaxed.

• One or the other heel is approximated to the opposite buttock (Fig. 8-19).

• After flexion of the knee, the thigh is hyperextended.

• With any significant hip lesion, performing this test will normally be impossible.

• With irritation of the iliopsoas muscle or its sheath, extending the thigh to any normal degree will be impossible.

• This test will aggravate inflammation of the lumbar nerve roots and will be accompanied by production of femoral radicular pain.

• The test will also stretch lumbar nerve root adhesions, which will be accompanied by upper lumbar discomfort.

FIG. 8-19

CLINICAL PEARL

In the uncommon cases of high lumbar and mid lumbar disc prolapse, the pain radiates toward the groin and front of the thigh rather than to the back of the thigh and leg.

FAJERSZTAJN TEST

ALSO KNOWN AS WELL-LEG-RAISING TEST OF FAJERSZTAJN, PROSTRATE LEG-RAISING TEST, SCIATIC PHENOMENON, AND CROSS-OVER SIGN

Assessment for Lumbar Nerve Root Lesion Caused by Intervertebral Disc Syndrome or Dural Sleeve Adhesion

ORTHOPEDIC GAMUT 8-9 LUMBAR CENTRAL CANAL STENOSIS

Structural causes for lumbar central canal stenosis are as follows:

1. Osseous: inferior facet arthrosis

2. Discogenic: central disc herniation

3. Ligamentous: ligamentum flavum buckling in degenerative spinal disease

PROCEDURE

• Straight-leg-raising and dorsiflexion of the foot are performed on the asymptomatic side of a sciatic patient (Fig. 8-20).

• When this test causes pain on the symptomatic side, Fajersztajn sign is present.

• The sign indicates sciatic nerve root involvement, such as a disc syndrome or dural root sleeve adhesions.

FIG. 8-20

CLINICAL PEARL

Several factors my produce pain in the back or lower extremities. Some of these causes are (1) tumors of the spinal cord or cauda equina, (2) tumors of the spinal column, (3) tuberculosis of the spine, (4) osteoarthritis, (5) tumors of the ilium or sacrum, (6) spondylolisthesis, (7) prolapsed intervertebral disc, (8) ankylosing spondylitis, (9) vascular occlusion, (10) intrapelvic mass, and (11) arthritis of the hip. All of these possible causes must be considered in differential diagnosis.

FEMORAL NERVE TRACTION TEST

Assessment for Mid Lumbar Nerve Root Involvement (L2, L3, and L4)

Comment

A large, midline disc herniation can compress several nerve roots of the cauda equina and can mimic an intraspinal tumor. Usually, lower back and perineal symptoms predominate, with radicular symptoms being masked. Difficulty with urination, such as frequency or overflow incontinence, may develop early. In men, a recent history of sexual impotence may be elicited. The patients experience pain down the posterior thighs to the soles of the feet accompanied by weakness of the legs and feet. L2, L3, and L4 radiculopathies are less common than the L5 and S1 radiculopathies, probably because of their relatively short course within the cauda equina, which makes them less susceptible to compression (Table 8-13).

TABLE 8-13 DIFFERENTIAL ELECTRODIAGNOSIS OF UPPER LUMBAR RADICULOPATHY

ORTHOPEDIC GAMUT 8-10 UPPER LUMBAR RADICULOPATHY

The electrophysiologic confirmation of an upper lumbar radiculopathy is challenging for the following reasons:

1. The exact compressed root is difficult to identify among upper lumbar roots because of the limited number of muscles innervated by the roots.

2. The myotomal representation of these roots occurs in proximally situated muscles, mostly above the knee (except for the tibialis anterior).

3. A lack of available sensory nerve action potential exists for confirming that the upper lumbar lesion is preganglionic.

PROCEDURE

• The side-lying patient slightly flexes the hip and knee on the unaffected side.

• With neck slightly flexed, the patient’s back is straight (not hyperextended).

• The affected limb is extended at the hip 15 degrees.

• The affected knee is flexed, stretching the femoral nerve (Fig. 8-21).

• If the test is positive, pain radiates into the anterior thigh.

FIG. 8-21

CLINICAL PEARL

Upper lumbar disc disturbances may cause weakness of the quadriceps muscle and a diminished or absent patellar reflex. The straight-leg-raising tests and signs may be negative. Pinwheel examination usually reveals hyperesthesia or hypoesthesia of the L4 dermatome.

HEEL/TOE WALK TEST

Assessment for L5 or S1 Nerve Root Motor Deficiency

Comment

Muscle weakness, atrophy, or the inability to perform functional testing maneuvers all suggest the presence of nerve root compression that is more significant than the alteration of sensation (Table 8-14).

TABLE 8-14 SPECIFIC DORSOLUMBAR RADICULOPATHY PATTERNS

ORTHOPEDIC GAMUT 8-11 ANATOMIC RELATIONS BETWEEN THE SCIATIC NERVE AND THE PIRIFORMIS MUSCLE

• Both peroneal and tibial components of sciatic nerve pass inferior to the piriformis muscle.

• Tibial component of the sciatic nerve passes inferior to the piriformis muscle; the common peroneal nerve passes through the muscle.

When the leg is shaken, such as during the test for alternating motion rate, the foot will be unstable and flop about. The foot is less floppy with central disorders (upper motor neuron lesions) and may be fixed in plantar flexion. When dorsiflexion of the ankles and toes is weak, the toes of the spastic leg are dragged during walking. Before the examiner concludes that weakness of dorsiflexion is present, the foot should be passively dorsiflexed to be certain that previous weakness, now healed, did not permanently shorten the gastrocnemius. Not unusual is for patients with severe L5 radiculopathy, in whom significant motor axon loss has occurred, to have foot drop (Table 8-15).

TABLE 8-15 ELECTROPHYSIOLOGIC DIFFERENCES BETWEEN L5 RADICULOPATHY AND PERONEAL NEUROPATHY

	L5 Radiculopathy	Peroneal Neuropathy
Nerve Conduction Studies
Peroneal CMAP, recording extensor digitorum brevis	Normal or low amplitude	Conduction block at fibular head, low amplitude, or both
Peroneal CMAP, recording tibialis anterior	Normal or low amplitude	Conduction block at fibular head, low amplitude, or both
Superficial peroneal SNAP	Normal	Low or absent; normal in deep peroneal or purely demyelinating lesions
Needle EMG
Tibialis anterior	Abnormal	Abnormal
Extensor digitorum brevis	Abnormal	Abnormal
Extensor hallucis	Abnormal	Abnormal
Peroneus longus	Abnormal	Abnormal; normal in selective deep peroneal lesions
Tibialis posterior	Abnormal	Normal
Flexor digitorum longus	Abnormal	Normal
Gluteus medius	May be normal	Normal
Tensor fasciae latae	May be normal	Normal
Lumbar paraspinals	May be normal	Normal

CMAP, Compound muscle action potential; EMG, electromyography; SNAP, sensory nerve action potential.

From Katirji B: Electromyography in clinical practice: a case study approach, St Louis, 1998, Mosby.

PROCEDURE

• The examiner observes the patient walking on the toes, which requires each foot, one at a time, to support the patient’s body weight completely (Fig. 8-22).

• If weakness exists, the heel will drop while the patient is walking.

• The contours of the musculature may demonstrate atrophy or hypertrophy.

• Having the patient walk on the heels is an especially valuable screening test because many muscular and neural disorders result in weakened dorsiflexion of the ankles and toes (Fig. 8-23).

• The patient may need help maintaining balance during this maneuver.

• The normal patient can hold the foot and toes anteriorly off the floor while strongly dorsiflexing the great toe during walking on the heels.

• If the patient can perform this maneuver, foot drop does not exist.

FIG. 8-22

FIG. 8-23

CLINICAL PEARL

The inability to walk on the toes indicates an L5–S1 disc problem based on weakness of the calf muscles supplied by the tibial nerve. The inability to walk on the heels indicates an L4–L5 disc problem based on weakness of the anterior leg muscles supplied by the common peroneal nerve.

HYPEREXTENSION TEST

Assessment for L3 and L4 Nerve Root Inflammation

ORTHOPEDIC GAMUT 8-12 MODIFIED WILTSE CLASSIFICATION OF LUMBAR SPONDYLOLISTHESIS ETIOLOGY

• Type 1, dysplastic (congenital) spondylolisthesis (congenital dysplasia of articular processes)

• Type 1a. The articular processes of L5 and S1 are dysplastic, having a horizontal rather than coronal orientation.

• Type 1b. The orientation of the facet joints is sagittal and the facets are malformed, allowing spondylolisthesis to occur typically in adult life.

• Type 1c includes other congenital malformations of the lumbar spine that permit spondylolisthesis.

• Type 2, isthmic (lytic) spondylolisthesis (This type occurs in the presence of bilateral pars defects, which can result from a variety of causes.)

• Type 2a. Lytic defects arise in the pars because of congenital weakness in the bone or repeated mechanical strain or both.

• Type 2b. The elongated pars is a true stress fracture of the pars.

• Type 2c. The pars fractures under acute trauma in cases that show complex fractures of the spine. Acute isolated pars fracture is exceedingly rare.

• Type 3, degenerative spondylolisthesis (This type is the most common cause of lumbar spondylolisthesis in patients older than 50 years. The neural arch is intact and the slip occurs because of degenerative changes in the facet joints with associated disc degeneration.)

• Type 4, traumatic spondylolisthesis (This type is rare and results from fractures or dislocations involving any part of the neural arch except the pars interarticularis, for example, the pedicle or the facet joints. It is almost always secondary to severe trauma.)

• Type 5, pathological spondylolisthesis (This type can be divided into two types.)

• Type 5a can occur when a generalized bone disease weakens the spine (i.e., Paget disease, osteoporosis, osteogenesis imperfecta, achondroplasia, arthrogryposis, osteopetrosis).

• Type 5b can occur when a focal disease process weakens the pars interarticularis, resulting in pathologic fracture and spondylolisthesis (i.e., syphilis, tuberculosis, neoplastic processes).

• Type 6, iatrogenic spondylolisthesis (This type can follow spinal decompression performed for spinal stenosis, laminectomy for disc removal, or any other spine surgery in which decompressing the spinal canal is necessary.)

PROCEDURE

• The patient is prone, and the legs are fully extended.

• The examiner anchors the patient’s lumbosacral spine with one hand.

• With the other hand, the examiner slowly extends the hip of the patient’s affected leg (Fig. 8-24).

• The test is positive if the patient experiences radiating pain in the anterior thigh.

• A positive test indicates inflammation of the L3 and L4 nerve roots.

FIG. 8-24

CLINICAL PEARL

Five criteria have been established for diagnosis of sciatica caused by a herniated intervertebral disc. (1) Leg pain is the dominant symptom when compared with back pain, and it affects only one leg and follows a typical sciatic or femoral nerve distribution. (2) Paresthesia is localized to a dermatomal distribution. (3) Straight leg raising is reduced to 50% of what is considered normal, and pain is elicited in the symptomatic leg when the unaffected leg is elevated. This pain radiates proximally or distally with digital pressure on the tibial nerve in the popliteal fossa. (4) Two of four neurologic signs (atrophy, motor weakness, diminished sensory appreciation, and diminution of reflex activity) are present. (5) A contrast study or other diagnostic imaging is positive and corresponds to the clinical level.

KEMP TEST

Assessment for Intervertebral Nerve Root Encroachment, Muscular Strain, Ligamentous Sprain, or Pericapsular Inflammation

ORTHOPEDIC GAMUT 8-13 MECHANISMS OF LUMBAR FACET PAIN

1. The facet joint can carry a significant amount of the total compressive load on the spine when the human spine is hyperextended.

2. Extensive stretch of the human facet joint capsule occurs when the spine is in the physiologic range of extreme extension.

3. An extensive distribution of small nerve fibers and free and encapsulated nerve endings exists in the lumbar facet joint capsule, including nerves containing substance P, a putative neuromodulator of pain.

4. Low- and high-threshold mechanoreceptors fire when the facet joint capsule is stretched or is subject to localized compressive forces.

5. Sensitization and excitation of nerves in facet joint and surrounding muscle occur when the joint is inflamed or exposed to certain chemicals that are released during injury and inflammation.

6. Marked reduction in nerve activity occurs in facet tissue injected with hydrocortisone and lidocaine.

ORTHOPEDIC GAMUT 8-14 DISC PROLAPSE

Disc prolapse usually follows lifting or twisting while the trunk is in flexion:

1. During the first stage, trunk flexion flattens the discs anteriorly and opens out the intervertebral space posteriorly.

2. During the second stage, as soon as the weight is lifted, the increased axial compression force crushes the whole disc and violently drives the nuclear substance posteriorly until it reaches the deep surface of the posterior longitudinal ligament.

3. During the third stage, when the trunk is nearly straight, the path taken by the herniating mass is closed by the pressure of the vertebral plateaus, and a hernia remains trapped under the posterior longitudinal ligament.

PROCEDURE

• While in a seated position, the patient is supported by the examiner, who reaches around the patient’s shoulders and upper chest from behind.

• The patient is directed to lean forward to one side and then around until the patient is eventually bending obliquely backward (Fig. 8-25).

• The maneuver is similar to that used for cervical compression.

• If this compression causes or aggravates a pattern of radicular pain in the thigh and leg, the sign is positive and indicates nerve root compression.

• Local back pain should be noted, but it does not constitute a positive test.

• However, local back pain may indicate a strain or sprain and thus be present when the patient leans obliquely forward or at any point in motion.

• Because elderly adults are less prone to an actual herniation of a disc because of lessened elasticity involved in the aging process, other reasons for nerve root compression are usually the cause.

• Degenerative joint disease, exostoses, inflammatory or fibrotic residues, narrowing from disc degeneration, and tumors must all be considered.

• This test must elicit a more positive finding when the patient is standing than when sitting (Fig. 8-26).

FIG. 8-25

FIG. 8-26

CLINICAL PEARL

Kemp test can be performed when the patient is either standing or sitting. Sitting increases intradiscal pressure and therefore maximizes stress on the disc. Standing increases weight bearing and maximizes stress to the facets. The test should be performed in both positions.

KERNIG/BRUDZINSKI SIGN

Assessment for Meningeal Irritation or Inflammation

ORTHOPEDIC GAMUT 8-15 MENINGEAL PATHOGENS AND ASSOCIATED OR PREDISPOSING CONDITIONS ^*

Organism	Associated Factors/Condition
Streptococcus pneumoniae	Pneumonia Otitis media Acute sinusitis Diabetes Splenectomy Hypogammaglobulinemia Head trauma CSF rhinorrhea Neonates, elderly adults Alcoholism, cirrhosis, peritonitis

Neisseria meningitidis

College dormitory living

Exposure in an endemic area

Complement deficiencies

Splenectomy

Hypogammaglobulinemia

Listeria monocytogenes

Immunosuppressive therapy

Organ transplantation

Pregnancy

Diabetes

Alcoholism

Neonates, elderly adults

Enteric gram-negative bacilli

Diabetes

Cirrhosis, alcoholism

Staphylococcus

Infective endocarditis

Parameningeal infection (empyema, epidural abscess, osteomyelitis)

Streptococcus agalactiae

Neonates, elderly adults

Diabetes

Alcoholism

Acquired immunodeficiency syndrome

Haemophilus influenzae type b

CSF, Cerebral spinal fluid.

^* Adapted from Roos KL: Bacterial meningitis, Curr Treat Options Neurol 1(2): 147-156, 1999.

PROCEDURE

• For the Brudzinski part of the sign, the patient is in the supine position, and the examiner passively flexes the patient’s head.

• The sign is present if flexion of both knees occurs (Fig. 8-27).

• The sign is often accompanied by flexion of both hips and is present with meningitis.

• For the Kernig part of the sign, the patient is supine.

• The examiner flexes the patient’s hip and knee of either leg to 90 degrees.

• The examiner attempts to completely extend the patient’s leg (Fig. 8-28).

• If this maneuver causes pain, the sign is present.

• The sign is often accompanied by involuntary flexion of the opposite knee and hip and is present in meningitis.

FIG. 8-27

FIG. 8-28

CLINICAL PEARL

After myelographic examination, a percentage of patients experience general malaise, headache, nausea, pain, and stiffness for a week or longer, and the symptoms are strikingly aggravated by the erect position or activity. These conditions may be signs of arachnoiditis. Subarachnoid fibrosis typically affects the lowermost segment of the thecal sac. This whole process represents meningismus or the apparent irritation of the spinal cord in which the symptoms simulate meningitis. However, no actual infectious agent—such as bacteria, fungi, or viruses—can be found.

LASÈGUE DIFFERENTIAL SIGN

Assessment for Intervertebral Radiculopathy Versus Hip Joint Disease

Comment

Examination often reveals restriction of low back motion. Bending toward the affected side typically exacerbates the pain. Variable degrees of local tenderness and muscle guarding are present. In an attempt to relieve tension on the nerve root, the patient may list or bend away from the painful side and stand with the affected hip and knee slightly flexed. A characteristic clinical picture may be present, depending on the level of nerve root involvement (Table 8-16).

TABLE 8-16 LUMBAR DISC SYNDROME PATTERNS

ORTHOPEDIC GAMUT 8-16 MODIFIED ALTMAN CLASSIFICATION OF HIP OSTEOARTHRITIS

Different classification systems have been described using as criteria the direction of migration of the femoral head and the evolution of the destructive changes within the joint. The two main types of head migration are as follows:

• The superior migration (or eccentric) may be superolateral or superomedial. The differential diagnosis of the superior migration pattern of the hip includes the calcium pyrophosphate dihydrate crystal deposition disease and the osteonecrosis, both of which might be complicated by secondary degenerative changes.

• The medial migration (concentric) is also known as axial or global. The concentric loss of articular cartilage poses diagnostic difficulties because it should be differentiated from infectious arthritis and rheumatoid arthritis.

PROCEDURE

• If the examiner flexes the hip of a patient with sciatica while the knee is extended and this movement elicits pain but flexing the thigh on the pelvis while the knee is flexed produces no sciatic pain, the sign is present (Fig. 8-29).

• This sign rules out hip joint disease.

FIG. 8-29

CLINICAL PEARL

Lasègue described how painful sciatica is for patients when the sciatic nerve is stretched by extending the knee while the hip is flexed. He also described the pain relief that occurs when the knee was then flexed. This reaction is the classic leg-raising sign. Variations of this sign, with interpretations of its meaning, lend much more knowledge to the examining physician than merely noting at what degree of leg raise the patient experiences either back pain, leg pain, or both.

LASÈGUE REBOUND TEST

Assessment for Intervertebral Nerve Root Lesion, Piriformis Muscular Spasm, Ischiotrochanteric Groove Adhesion, or Intervertebral Disc Syndrome

ORTHOPEDIC GAMUT 8-17 CAUSES AND PREDILECTION FOR PIRIFORMIS SYNDROME

• The female-to-male predominance is 6:1.

• The most common cause of piriformis syndrome is trauma to the pelvis or buttock (50%).

• However, the trauma is usually not dramatic and may occur several months before initial symptoms.

• Prolonged sitting, although uncommon, has been recognized as a cause of piriformis syndrome.

ORTHOPEDIC GAMUT 8-18 DISC HERNIATION VERSUS OTHER CAUSES OF BACK PAIN

The following elements apply when early disc herniation is difficult to differentiate from other causes of back pain:

1. Plain-film roentgenograms are indicated within 2 to 4 weeks of onset.

2. Electromyography, computed tomography (CT), magnetic resonance imaging (MRI), or myelography confirm the diagnosis.

3. Electromyography (EMG), CT, and MRI are not usually indicated for at least 4 to 6 weeks from onset.

4. EMG, CT (if surgical intervention is being contemplated), or MRI is indicated if other more serious spinal disease is suspected.

5. Discography is considered to be of only limited value.

PROCEDURE

• To continue a differential after the straight-leg-raising test, the examiner fixes the patient’s pelvis on the same side by pressing heavily with a hand on the region of the ipsilateral anterosuperior iliac spine and repeats this straight-leg-raising test.

• Any undue pain experienced by the patient is associated with sciatic involvement resulting from a nerve root disorder, piriform spasm, or ischiotrochanteric groove adhesions.

• Differentiation of piriformis spasm from other causes can be accomplished by reproducing the pain during internal rotation of the femur when it is at a lower level than the original point of pain.

• After a positive Lasègue test, the examiner may permit the leg to drop to the examination table without warning the patient (Fig. 8-30).

• If this Lasègue rebound test causes a marked increase in the back pain, sciatic neuralgia, and muscle spasm, then disc involvement is suspected.

FIG. 8-30

CLINICAL PEARL

The relationship of the lumbar roots and the lumbar discs is of major clinical importance. A massive posterior extrusion of one of the lumbar discs may severely injure the cauda equina (both intrathecal and extrathecal roots). Although these lesions are rare, they do occur. In these instances, the size and shape of the spinal canal and the size of the extruded mass are major factors in the severity of the clinical syndrome.

LASÈGUE SITTING TEST

Assessment for Sciatic Nerve Inflammation

ORTHOPEDIC GAMUT 8-19 ETIOLOGY OF NEUROGENIC CLAUDICATION PAIN

• Direct compressive forces on the nerves, particularly in the lateral recesses and foramina of the lumbar spinal canal, where the nerves exit

• Compromised blood supply to the nerve root as a result of the compression, leading to nerve pain similar to the muscular pain of vascular claudication

• Lack of nerve root nutrition resulting from stenosis-induced stagnation of cerebrospinal fluid

ORTHOPEDIC GAMUT 8-20 LUMBAR CANAL STENOSIS

Electromyographic (EMG) findings in lumbar canal stenosis include the following:

1. An entirely normal EMG

2. Absent H-reflex only, unilaterally or bilaterally

3. Denervation in a single root distribution (single radiculopathy), unilaterally or bilaterally and asymmetrically

4. Occurrence of bilateral and asymmetric lumbosacral radiculopathies, affecting the L5, S1, and S2 roots (the most common EMG finding associated with lumbar canal stenosis) (Table 8-17)

TABLE 8-17 ELECTROPHYSIOLOGIC DIFFERENTIATION OF CHRONIC S1/S2 RADICULOPATHY

ORTHOPEDIC GAMUT 8-21 LUMBOSACRAL RADICULOPATHY

Electromyographic (EMG) limitations in lumbosacral radiculopathy are as follows:

1. If the dorsal root is the only root compressed, and if the ventral root is normal, then the EMG examination is normal. This scenario occurs in a significant number of patients whose symptoms are limited to pain or paresthesia or both. Thus, a normal EMG does not exclude root compression.

2. Fibrillation potentials can be absent from the paraspinal muscles, particularly in chronic radiculopathies. This circumstance is likely caused by reinnervation. In contrast, fibrillation potentials can be present in the paraspinal muscles after lumbar laminectomy because of denervation during surgical exposure.

3. The lower-extremity sensory nerve action potentials (SNAPs) often are unevocable bilaterally in elderly patients. When this circumstance occurs, differentiating a preganglionic lesion (i.e., lumbosacral radiculopathy) from a postganglionic lesion (i.e., lumbosacral plexopathy) is often difficult unless fibrillation potentials are evident in the paraspinal muscles.

4. No SNAPs have been devised to assess the L2 or L3 fibers up to the dorsal root ganglion, and the saphenous SNAP is not technically reliable (especially in elderly and obese patients) to assess the L4 fibers. Thus, separating an upper lumbar radiculopathy (especially L2 and L3) from lumbar plexopathy is often difficult unless fibrillations are present in the paraspinal muscles.

ORTHOPEDIC GAMUT 8-24 DIAGNOSTIC CRITERIA OF RESTLESS LEGS SYNDROME ^*

Essential criteria:

1. Urge to move legs is usually accompanied or caused by uncomfortable or unpleasant sensations in the legs.

2. Urge to move or unpleasant sensation begins or worsens during periods of rest or inactivity.

3. Urge to move or unpleasant sensation is partially or totally relieved by movement as long as activity continues.

4. Urge to move or unpleasant sensation is worse in the evening or at night than during the day, or the urge occurs only during the evening or at night.

Supportive clinical features:

1. Positive family history

2. Response to dopaminergic therapy (>90%)

3. Periodic limb movements (during wakefulness or sleep)

Associated features:

1. Natural clinical course

2. Sleep disturbance

3. Medical or physical evaluation is generally normal

^* Adapted from Allen RP, Earley CJ: Restless legs syndrome: a review of clinical and pathophysiologic features, J Clin Neurophysiol 18(2):128-147, 2001.

PROCEDURE

• The patient is seated upright on the edge of a table with the legs dangling.

• The examiner faces the patient and extends the patient’s leg at the knee.

• The lower extremity from the hip to the foot is made parallel with the floor (Fig. 8-31).

• When radiculoneuropathy is not present, the patient should not experience discomfort from this action.

• Initially, the significance of the test is the same as the Lasègue test.

• However, the modification of performing the straight leg raise while the patient is in the seated position provides several advantages.

• In the supine position, straight leg raising may be difficult because the patient may squirm and shift the pelvis, making the leg abduct and rotate.

• The apprehensive patient may attempt to ward off anticipated pain and make the test positive sooner than is warranted.

• When the test is performed in the seated position, the patient faces the examiner, feels more secure and at ease, and is less likely to even know the part is being tested.

• The test has excellent, objective values when the examiner is able to determine immediately the slightest attempt on the part of the patient to withdraw by leaning back from the induced pain.

FIG. 8-31

CLINICAL PEARL

By raising the patient’s foot, the examiner has performed a modified straight-leg-raising test. Because the thigh is already flexed to 90 degrees in this position, straightening the knee to the horizontal places stretching forces on the nerve roots. The results of this seated tension should correspond to the results obtained from the tests performed in the supine position.

LASÈGUE TEST

ALSO KNOWN AS LASÈGUE SIGN

Assessment for Sciatica Resulting from Lumbosacral or Sacroiliac Lesions, Lumbar Subluxation Syndrome, Intervertebral Disc Lesion, Spondylolisthesis, Dural Sleeve Adhesions, or Intervertebral Foramen Occlusion (Encroachment)

ORTHOPEDIC GAMUT 8-25 LASÈGUE TEST

Interpretations of the Lasègue test:

1. When the patient is supine and the lower limbs are resting on the examination table, the sciatic nerve and its roots are under no tension.

2. When the lower limb is raised while the knees are flexed, the sciatic nerve and its roots are still under no tension.

3. If the knee is extended while the leg is elevated, the sciatic nerve, which must cover a longer distance, is subjected to increasing tension. In the normal patient, the nerve roots slide freely through the intervertebral foramen, and no pain results. When the lower limb is nearly vertical for people with diminished flexibility, pain is felt on the posterior aspect of the thigh as a result of stretching the hamstrings. However, this pain does not constitute a positive Lasègue sign.

4. When one nerve root is trapped in the foramen or when the root must cover a longer distance because of a prolapsed disc, any stretching of the nerve will become painful with moderate elevation of the lower limb. This result constitutes a positive Lasègue sign, which is evident before 60 degrees of flexion is attained. Pain may be elicited at 10, 15, or 20 degrees of flexion, which allows a rough quantification of the severity of the lesion.

ORTHOPEDIC GAMUT 8-26 PRECAUTIONS FOR LASÈGUE TEST

Two precautions to observe in performing Lasègue test:

1. The examiner must always elicit the Lasègue sign cautiously and stop when the patient feels pain.

2. The examiner must never attempt to elicit the Lasègue sign when the patient is under general anesthesia because the protective pain reflex is absent. The reflex can occur when the patient is being placed prone on an operating table and the hips are allowed to flex while the knees are extended. Hip flexion must always be associated with knee flexion, which relaxes the sciatic nerve and the trapped root.

PROCEDURE

• The patient lies supine with legs extended.

• The examiner places one hand under the ankle of the patient’s affected leg and the other hand on the knee and flexes the thigh on the pelvis while the knee is flexed.

• The examiner then slowly extends the patient’s knee while the leg is elevated (Fig. 8-32).

• If this maneuver is markedly limited because of pain, the test is positive and suggests sciatica from lumbosacral or sacroiliac lesions, subluxation syndrome, disc lesions, spondylolisthesis, adhesions, or intervertebral foramen occlusion.

FIG. 8-32

CLINICAL PEARL

Whenever the presence of the Lasègue sign is questionable, the examiner should combine this test with flexion of the cervical spine (Lindner sign). This combination places the greatest pull and stretch on the nerve roots behind the intervertebral discs and often elicits pain.

LEWIN PUNCH TEST

Assessment for Generalized Spinal Lesion or Intervertebral Disc Protrusion

PROCEDURE

• Punching the buttock produces a referred pain in the back.

• While the patient is standing, the examiner percusses (punches) the side of the patient’s buttock with the lesion (Fig. 8-33).

• If this percussion (punch) elicits pain, the test is positive.

• Punching the opposite buttock should not elicit pain.

• The test is significant for a spinal lesion, usually involving a protruded disc.

FIG. 8-33

CLINICAL PEARL

In some instances of an acute attack, even light fist percussion over the lumbar spine in the midline will produce such severe accentuation of the local and radiating pain that the patient’s knees may buckle. Some evidence of a vasovagal response may be found. In patients with spondylolysis or spondylolisthesis, hamstring tightness and the classic Phalen-Dickson sign—a knee-flexed, hip-flexed gait—may be demonstrated, regardless of degree of slippage. The mechanism for hamstring tightness is unclear, but it may be caused by nerve root irritation from the instability. For higher degrees of slip, the sacrum becomes more vertical so that the pelvis is more flexed and the hips cannot hyperextend enough to maintain upright posture. Therefore, the patient must flex the knees to stand upright.

LEWIN SNUFF TEST

Assessment for Intervertebral Disc Rupture or Space-Occupying Mass

PROCEDURE

• An aromatic substance is introduced, and the patient is instructed to sniff it up the nostril so as to induce sneezing.

• The test is positive when sneezing elicits an exacerbation of well-localized spinal and radicular pain (Fig. 8-34).

• The test is significant for intervertebral disc rupture.

FIG. 8-34

CLINICAL PEARL

The sneeze produces a sudden Valsalva maneuver. If the examiner assumes that motion of an irritated nerve root over a disc bulge is one of the causes of pain, any production of a Valsalva effect abruptly increases the patient’s pain as the defect appears and disappears and thereby moves the nerve root over the disc.

LEWIN STANDING TEST

Assessment for Unilateral or Bilateral Hamstring Spasm

PROCEDURE

• The patient is standing.

• From behind, the examiner stabilizes the patient’s pelvis with one hand while sharply pulling the knee on that side into extension (Fig. 8-35).

• The examiner then repeats this move on the opposite side and braces a shoulder against the patient’s sacrum and sharply pulls both of the patient’s knees into extension.

• The test is positive when pulling one or both knees into extension elicits pain that is followed by one or both knees snapping back into flexion.

• This positive finding represents unilateral or bilateral hamstring spasm.

FIG. 8-35

CLINICAL PEARL

Tight or contracted hamstrings pull eccentrically on the pelvis. The patient with suspected tight hamstring disorder can be examined in the supine position. Keeping the hips and buttocks in contact with the table, straight leg raising is performed bilaterally. The comparison will indicate any hamstring contracture or tightness.

LEWIN SUPINE TEST

Assessment for Lumbar Arthritis, Lumbar Fibrosis, Spondylosis, Sacroiliac or Lumbosacral Arthrosis, or Sciatica

Comment

With lumbar spondylosis accompanied by a stenotic lumbar spinal canal, the physical examination is unrevealing despite intermittent symptoms that are often severe. Flexion and straight leg raising are often performed without difficulty. Severe pain during lumbar extension may be the only positive result. Rheumatoid arthritis must be included in the differential diagnoses (Tables 8-18 and 8-19).

TABLE 8-18 LARSEN AND THE MODIFIED LARSEN RHEUMATOID ARTHRITIS GRADING SYSTEM

TABLE 8-19 LUMBAR SPINAL RHEUMATOID ARTHRITIS LESION GRADES

Grades II and III are further divided into two types. Type A includes grade IIA (presence of disc narrowing) and grade IIIA (disc space collapsed and vertebral bodies fused), and type B includes grade IIB (absence of disc narrowing) and grade IIIB (vertebral body collapsed but intervertebral disc remains or appears ballooned).

From Sakai T et al: Radiological features of lumbar spinal lesions in patients with rheumatoid arthritis with special reference to the changes around intervertebral discs, Spine J 8(4): 605–611, 2008.

ORTHOPEDIC GAMUT 8-27 DISC DEGENERATION

Observations in disc degeneration:

1. Disc degeneration may occur and may remain asymptomatic.

2. Disc degeneration may be associated with changes within the disc itself, which may produce pain.

3. Disc degeneration may give rise to mechanical instability that renders the spine vulnerable to trauma.

PROCEDURE

• While the patient is supine, the examiner supports the patient’s legs on the table.

• The patient is directed to sit up without using the hands (Fig. 8-36).

• The test is positive if the patient is unable to perform this action.

• A positive test is often associated with lumbar arthritis, lumbar fibrosis, degenerative disc thinning with protrusion, sacroiliac or lumbosacral arthritis, and sciatica.

• The patient is often able to localize the site of the complaint.

FIG. 8-36

CLINICAL PEARL

The security and comfort of the back depend not only on the lumbar muscles and ligaments, but also on the strength of the abdominal wall and prevertebral muscles. The abdomen should be palpated to determine whether divarication of the rectus abdominis muscle is present. The clinical test for diagnosis of rectus divarication involves instructing the supine patient to raise the head from the examination table. The examining hand can easily feel the gap between the contracted pillars of the rectus, and the fingers will sink into the soft abdominal wall. The width of the gap may vary from 1 cm to a hand’s breadth.

LINDNER SIGN

Assessment for Lumbar Nerve Root Irritation or Inflammation

ORTHOPEDIC GAMUT 8-28 UNILATERAL DISC HERNIATION BETWEEN L3 AND L4

Unilateral disc herniation between L3 and L4 usually compresses the fourth lumbar root as it crosses the disc before exiting at the L4 intervertebral foramen with the following results:

1. Pain may be localized around the medial side of the leg.

2. Numbness may be present over the anteromedial aspect of the leg.

3. The quadriceps and hip adductor group, both innervated from L2, L3 and L4, may be weak and, in extended ruptures, atrophic.

4. Reflex testing may reveal a diminished or absent patellar tendon reflex (L2, L3, and L4) or tibialis anterior tendon reflex (L4).

5. Sensory testing may show diminished sensibility over the L4 dermatome, the isolated portion of which is the medial leg, and the autonomous zone, which is at the level of the medial malleolus.

ORTHOPEDIC GAMUT 8-29 UNILATERAL DISC HERNIATION BETWEEN L4 AND L5

Unilateral disc herniation between L4 and L5 results in compression of the fifth lumbar root with the following results:

1. Fifth lumbar root radiculopathy should produce pain in the dermatomal pattern.

2. Numbness, when present, follows the L5 dermatome along the anterolateral aspect of the leg and the dorsum of the foot, including the great toe.

3. The autonomous zone for this nerve is the first web of the foot and the dorsum of the third toe. Weakness may involve the extensor hallucis longus (L5), gluteus medius (L5), or extensor digitorum longus and brevis (L5).

4. Reflex change is not usually found.

5. A diminished tibialis posterior reflex is possible but difficult to elicit.

ORTHOPEDIC GAMUT 8-30 UNILATERAL DISC HERNIATION BETWEEN L5 AND S1

In a unilateral disc herniation between L5 and S1, the findings of an S1 radiculopathy are noted as follows:

1. Pain and numbness involve the dermatome of S1.

2. The S1 dermatome includes the lateral malleolus and the lateral and plantar surface of the foot, occasionally including the heel.

3. Numbness is present over the lateral aspect of the leg and, more important, over the lateral aspect of the foot, including the lateral three toes.

4. The autonomous zone for this root is the dorsum of the fifth toe.

5. Weakness may be demonstrated in the peroneus longus and brevis (S1), gastrocnemius-soleus (S1), or gluteus maximus (S1).

6. In general, weakness is not a usual finding in S1 radiculopathy.

7. Occasionally, mild weakness may be demonstrated by asymmetrical fatigue with exercise of these motor groups.

8. The ankle jerk usually is reduced or absent.

PROCEDURE

• Passive flexion of the patient’s head onto the chest can be accomplished in a supine, seated, or standing position (Fig. 8-37).

• If pain occurs in the lumbar spine and along the sciatic nerve distribution, the test is positive and, according to Lindner, is an indication of root sciatica (Fig. 8-38).

FIG. 8-37

FIG. 8-38

CLINICAL PEARL

Flexion of the head to the chest increases the traction of the nerve root against the disc bulge. When the disc is a contained disc, in which the annulus is not ruptured, the flexion or maintenance of a flexed position of the trunk obliterates the disc bulge. Motion of an irritated nerve root over a bulging disc is often the source of the patient’s back and leg pain. Relief of pain with trunk flexion occurs only because the disc bulge has disappeared.

MATCHSTICK TEST

Assessment for Denervation Hypersensitivity

Comment

Many cases of acute low back pain that are not correctly identified evolve into a chronic spinal problem with significant disability at the muscular level (Table 8-20). Patients with muscular dysfunction of the lumbar spine can have varying types of clinical findings and case histories.

TABLE 8-20 SITES OF LUMBOPELVIC SOFT-TISSUE SYNDROMES/MYOFASCIAL TRIGGER POINTS

Diagnosis	Site of Complaint
Quadratus lumborum syndrome	Gluteal region, anterior iliac spine, greater trochanter of femur
Gluteus maximus or medius syndrome	Sacral and gluteal region, lateral hip
Gluteus minimus syndrome	Lateral hip, thigh, and calf
Chronic lumbar strain (spinal erector muscles)	Laterally to ribs, caudally toward lumbosacral junction
Piriformis syndrome	Sacroiliac region; posterior hip, thigh, calf; possibly sole of foot