Doubt remains as to the safest surgical approach to the prolapsed thoracic intervertebral disc. Laminectomy, lateral rhachotomy and the transthoracic approach all have their protagonists.

Twenty-two patients from the National Hospital for Nervous Diseases, Queen Square, and Atkinson Morley's Hospital have been reviewed. Their clinical presentation is discussed and the ancillary aids to diagnosis assessed. The diagnostic value of disc space calcification is stressed, and the use of air myelography as an adjunct to positive contrast myelography is noted.

Fifteen patients were subjected to laminectomy, and seven to lateral rhachotomy. Each group contained patients with a wide range of neurological deficit. Six of the patients who underwent laminectomy were improved, two were unchanged, six deteriorated and one died. Of the patients who had lateral rhachotomy, six were improved, one was unchanged and none deteriorated. The conclusion is drawn that lateral rhachotomy is a safer procedure.