Discography in evaluation of lumbar disk lesions.

Abstract

Since Lindblom's original description of discography, considerable interest has been evinced in this procedure as a means of evaluating lesions of the lumbar intervertebral disks. On the basis of extensive anatomic dissection, Lindblom (4) catalogued the character, the frequency, and the pathologic findings in disk lesions in 160 autopsies. As a part of this anatomic investigation he injected red lead into the lumbar disk and was able to study the degree of degeneration, the direction of protrusion of the nucleus, and the presence of rupture within the disk, roentgenographically. In 1948, he first described the clinical application of discography (5). By injecting 35 per cent Perabrodil (Diodrast) as a contrast material directly into the nucleus of the disk, by puncture with a fine, thin needle, he was able to visualize the internal architecture. He described the normal disk, the degree and direction of fissuring, and the appearance of disks which showed variable degrees of degeneration, protrusion, and epidural leak. He demonstrated, also, that in a high percentage of cases the injection of a pathological or offending disk will reproduce the patient's pain. Thus one can determine if the injected disk is the source of the symptoms, or if a disk, even though it be degenerated, is still not producing symptoms. By this method the examiner is afforded a direct knowledge of the pathological condition of a disk, and in a high percentage of cases he can correlate it with the clinical symptoms. Myelography has been an aid in the localization and determination of disk protrusion. Clinicians, however, evaluating the results of this procedure at surgery, have found that errors occur in its use. Patients with clear-cut symptoms and proved protrusions may have negative myelograms while, as in many other examinations, false positives occasionally occur. Material and Method It is the purpose of this report to present an analysis and critical review of the findings in 150 cases of back pain seen in the practice of one of the essayists, an orthopedic surgeon (MZG), in which discography was performed. It is essential to emphasize that not all patients with backache in his practice were referred for this examination; nor were all those with backaches thought to be due to disk lesions operated upon. A large group who were treated conservatively were not referred for examination. Others who were eventually referred were originally treated conservatively for variable periods, with the hope that spontaneous improvement might result. Many patients were not referred because the backache was not disabling. In some who had clear-cut symptoms and neurological findings which allowed good clinical localization of the offending disk, myelograms or discograms were not considered necessary and, if surgery were indicated, it was sometimes done without these procedures.