Myelography in lumbar spondylolisthesis.

Radiography and myelography of 41 patients with lumbar spondylolisthesis and radicular syndrome were analysed. The L5 olisthesis in several aspects differed from the L4 olisthesis. Root pocket amputation was the most common explanation for the radicular syndrome but sometimes present without clinical signs. In this series disc herniation was uncommon and its diagnosis difficult. Total or subtotal block of the subarachnoid space was also uncommon but this diagnosis enforced the indication for decompressive operation.