Protrusions of Disks and Nerve Compression in the Lumbar Region

Two years ago the author of the present paper published a report on the results of an anatomic study of protrusions of disks through the intervertebral foramina of the lumbar vertebrae. The following pararaph summarizes the conclusions reached. Dorsolateral protrusions of disks at the intervertebral foramina are often observed in anatomic specimens, and these are largely combined with compression of the nerves and ganglia on a line with the outer part of the foramina at the point where the nerve pierces the disk. At a lecture read before a meeting of the Swedish Societies for Internal Medicine and Medical Radiology, in December 1941, the writer expressed the opinion that these nerve compressions are so common that no further explanation need be sought to account for the symptoms occurring in the large majority of sciatica cases; in other words, »Sciatica means the rupture of a disk». This thesis aroused opposition, however, and severe criticism was directed from many quarters against the interpretation placed on the anatomic findings and the absence of clinical information with regard to sciatic pain in most of the cases reported. The writer has therefore extended his studies, and the present communication offers an account of both the earlier results and those obtained from the later investigation. The previous literature on the subject is almost exclusively concerned with protrusions and ruptures of disks into the vertebral canal, whereas herniated disks with a more lateral location, causing compression of the nerves, such as those described by the writer, have not earlier received attention or been attributed much clinical significance. The AngloAmerican literature of the past two years has not been available for study, however. Of the publications from other countries, mention may be made