Studies on the pathology of low back pain.

It is now about thirty years since Schmorl (1929) described structural changes in intervertebral discs and in intervertebral bodies observed at necropsy. Disc surgery during the last twenty-five years has shown that there is a high incidence of disc ruptures in patients with low back pain and sciatica, and there is a wide belief that low back pain originates in the discs. Although it can be well understood and accepted that structural disc changes may lead to circumscribed local disc sequestrations, causing mechanical pressure on lumbar nerve roots, the underlying mechanism of low back pain is still not known. Since 1940 a number ofinvestigations have been done in Sweden in order to correlate the clinical picture of low back pain with structural changes in lumbar intervertebral discs.