CERVICAL SPONDYLOTIC MYELOPATHY - A REVIEW OF SURGICAL INDICATIONS AND DECISION-MAKING

Cervical spondylotic myelopathy (CSM) is frequently underdiagnosed and undertreated. The key to the initial diagnosis is a careful neurologi c examination. The physical findings may be subtle, thus a high index of suspicion is helpful.Poor prognostic indicators and, therefore, abs olute indications for surgery are: 1. Progression of signs and symptom s. 2. Presence of myelopathy for six months or longer. 3. Compression ratio approaching 0.4 or transverse area of the spinal cord of 40 squa re millimeters or less. Improvement is unusual with nonoperative treat ment and almost all patients progressively worsen. Surgical interventi on is the most predictable way to prevent neurologic deterioration. Th e recommended decompression is anterior when there is anterior compres sion at one or two levels and no significant developmental narrowing o f the canal. For compression at more than two levels, developmental na rrowing of the canal, posterior compression, and ossification of the p osterior longitudinal ligament, we recommend posterior decompression. In order for posterior decompression to be effective there must be lor dosis of the cervical spine. If kyphosis is present, anterior decompre ssion is needed. Kyphosis associated with a developmentally narrow can al or posterior compression may require combined anterior and posterio r approaches. Fusion is required for instability.