Short term prognosis in sciatica. A prospective study of factors influencing the results with special reference to myelography.

334 Types of follow-up data were collected in 158 patients with sciatica. The following information was obtained: (a) in L4-L5 herniations, Achilles tendon reflex disturbance was not explained by S1 root compression, as visualized at this level on myelography, (b) a water-soluble myelogram was also reliable for extreme lateral herniations and only those herniations dislocated into the intervertebral root canal remained undiagnosed, (c) a positive neurological or myelographic diagnosis of herniation did not mean a better short-term prognosis. Operative removal of a large herniated mass gave the best chance of good recovery. The main indication for myelography is a guide to the surgeon for the correct operative level.