We describe a lumbar facet syndrome in which disabling symptoms are associated with normal or near-normal plain radiographs. Local spinal fusion relieved symptoms in 12 patients; the excised facet joint surfaces showed some of the histological changes seen in chondromalacia patellae and in osteoarthritis of other large joints. The most frequent change was focal full-thickness cartilage necrosis or loss of cartilage with exposure of subchondral bone, but osteophyte formation was remarkably absent in all specimens. We suggest that there are both clinical and histological similarities between the facet arthrosis syndrome and chondromalacia patellae. Facet arthrosis may be a relatively important cause of intractable back pain in young and middle-aged adults.

Three patients referred for rehabilitation of brachial plexus lesions and two referred with leg weakness associated with sciatica were found to have conversion paralysis. The diagnosis was made by demonstrating normal motor nerve conduction to the clinically weak muscles. The weakness was treated by intensive physical rehabilitation with complete and sustained recovery in all cases.

A series of 100 patients with pain in the leg was studied and the accuracy of electrical studies in the diagnosis of nerve root lesions was investigated before operation. The electrical studies which were performed on all the patients, included recordings of fibrillation potentials, H-reflex and ankle reflex latencies. This diagnosis technique was found to be more accurate than radiculography or clinical examination and did not give false evidence. Seventy patients were classed as having a lesion of the nerve root. Fifty of these patients were treated surgically. The operation revealed compression of the nerve root by osteophytes arising from degenerative and incompletely dislocated posterior facet joints in 43 patients.

In 15 patients who underwent open exploration of the brachial plexus, the somatosensory evoked potentials and nerve action potentials recorded at the time of operation were useful as guides to the most appropriate surgical procedure, and also in predicting the outcome in certain lesions. In three patients the apparent normality of the upper trunk of the plexus was concealing a more proximal lesion which was irrecoverable. The presence of a somatosensory evoked potential showed functional continuity in three patients in whom the C7 root was clinically involved and who recovered after operation. In five patients proximal stumps of ruptured C5 roots showed functional central continuity; this indicated their suitability for grafting. These patients recovered except one who suffered from co-existing disease. The electrophysiological studies also confirmed the clinical diagnosis of avulsion of the C8 and T1 roots and therefore prevented unnecessary dissection.