REIDER PART 2
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Charter 9    Lumbar Spine 337

discrepancy are discussed in Chapter 5, Pelvis, Hip, and Thigh. In the case of a leg length discrepancy, a secondary compensatory deformity of the spine is usually present. List. Any departure from symmetry in the lumbar spine is usually caused by a coronal piane deformity. A list is an abrupt planar shift of the spine, abovc a certain point, to one side (Fig. 9-2). This phenomenon typically occurs primarily in the lumbar spine. It is usually a reversible deformity related to pain and associated muscle spasm. A list may be caused by a herniated lumbar disk. In this case, the spine shifts away from the side of the ncrvc root that is being pinched by the herniated lumbar disk in an attempt to rclieve pressure from the affected nerve root. Sometimes, local muscle strain can also result in a list. Scoliosis. Scoliosis is another major cause of coronal asymmetry (Fig. 9-3A). Although scoliosis is usually con-sidered a coronal deformity of the spine, it is really a hel-ical abnormality involving abnormal vertebral rotation along the axis of the spine. Lumbar scoliosis may be pri-mary or secondary. In primary scoliosis, an actual struc-tural abnormality of the spine is present. In secondary scoliosis, the curvature represents a compensatory adap-tation of an otherwise normal spine to an extrinsic factor, sucli as muscle spasm or pelvic obliąuity related to a leg length discrepancy. If the condition is secondary to a pelvic obliquity, leveling the patients pelvis by placing blocks or books beneath the shorter limb should cause the deformity to disappear. If a pelvic obliquity has been present for a long time, howcver, permanent soft tissue contractures may develop; conscquently, the deformity ceases to be reversible by leveling the pelvis.

As in the cervical and the thoracic spine, lumbar scoliosis may be idiopathic or due to neurologie disorders or vertebral anomalies. The bulkier lumbar musculature may disguise the spinał curve, and the rib hump that often alerts the examiner to the presence of thoracic scoliosis may be mild or absent. Clues such as pelvic obliq-uity or asymmetry of the spaces between the upper limbs and the trunk are, therefore, extremely important in detecting lumbar scoliosis.

Skin and Subcutaneous Tissue Abnormalities. The

examiner should also notę any abnormalities of the skin

Figurę 9-2. A and B, A list to the left. Notę the asymmetry of the spaccs between the arms and the trunk in A and the inerease in the list with flexion in B.