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In 1934, an article in the New England Journal of Medicine1, concluded that extremity pain related to the spine was primarily associated with disrupted disc material compressing nerves. Since then, it has been difficult to "prove" a physiological basis for such pain without showing such disc disruption and nerve compression. Now, an increasing body of medical evidence indicates that the issue is not that simple. This article looks at the results of one of the latest reported studies... Patients with disc disease confined to the interior of the disc (without bulges or ruptures) are as likely to have thigh pain and lower leg pain as patients with bulges or total ruptures of the outer fibers of the disc, according to a study reported recently in Spine2. Although our readers trained in medicine will know more about this than those of us in the legal profession, we wish to report on the results of this study since they appear to us to be significant to the medical-legal world. The study involved 187 patients who had completed pain drawings just prior to undergoing CT discography at the three lowest lumbar levels for diagnostic purposes. All patients had persistent pain, despite conservative care. The pain drawings showed the extent and location of three categories of lower extremity pain: 1) back and buttocks only; 2) extending to thigh, but not below the knee; and 3) extending below the knee. If unusual patterns appeared on the pain drawings, the patient was not included in this analysis since these suggested psychological problems and were classified as abnormal. The study focussed on two levels of severity of disc disruption, as revealed by the discographies. The more severely disrupted discs showed deformation of the outer wall of the disc and, in some cases, herniation of the disc material through the outer anulus or leakage from the disc space. The discs which were less severely disrupted had ruptured outer anulus layers, with no deformity of the outer wall and no leakage from the disc space. The purpose of the study was to determine if there was any difference in pain location or type with respect to the severity of Iumbar disc disruption. Here are some of the results: - There were no significant relationships between symptom duration and the degree of disc disruption, nor between symptom duration and how far the pain extended into the extremities. - Also, there was no significant difference in the proportion in the three pain location groups between the two levels of severity of disc disruption. In fact, patients with less severe symptomatic disc disruption used significantly more symbols to indicate their pain than did the patients with more severely disrupted discs. For example, patients of lesser severity reported significantly more aching pain than those patients with more severe disruption. - Lower extremity pain was as likely to be associated with symptomatic disc disruption confined to the outer layers of the anulus not deforming the outer wall (less severe) as with the more severe symptomatic disruption which did deform the outer wall. Also, aching pain, which the "less severe" patients complained of with significantly more frequency, is typically thought to be characteristic of "referred" pain! The study could not address definitively whether the more severely disc-disrupted patients' pain was due to nerve root compression, biochemical pain related to leakage of disc materials into the epidural space, referred pain, or a combination of these. However, the study did show that patients whose disc disruption was limited to the interior of the disc (without bulges) were as likely to have thigh pain or leg pain as those with bulges or total ruptures of the anular fibers and deformity of the outer disc wall. The authors of the article recognized that determining the source, or sources, of symptoms can be very difficult and that further investigation is needed. In closing, they caution: "It is important when trying to determine the sources of symptoms not to consider only one possibility and pass off the patient's pain as psychogenic if the evaluator's initial suspicion is not correct." We believe this significant study merits dialogue, so the medical and legal communities may together grasp its full import to our patients and clients. From the legal standpoint, we have represented hundreds of persons who following a work or accident injury suffered with pain in their lower extremities - pain which IME doctors found suspect for the supposed lack of a physiologic source. In the 27 years that I have been a lawyer, I have observed dramatic changes in the state of the art of treating and diagnosing spinal and musculoskeletal injuries. This study appears to be the latest step in our evolution towards understanding injuries whose symptoms were once thought to be unexplainable and therefore potentially suspect. We invite your comments. Contact us locally at 772-9850, or toll-free at 1-800-525-2099, or by e-mail at bcws@cdsnet.net. 1 Mixter WJ, Barr JS. Rupture of intervertebral disc with involvement of the spinal canal. N. Engl. Med. 1934;211:210-5. 2 Ohnmeiss DD, Vanharanta H. Ekholm J. Degree of disc disruption and lower extremity pain. Spine 1997, 22:1600-5 [For more on causes of radicular low back pain, see Sella FJ. Noncompressive Spinal Radiculitis. Orthop Rev. 1992; July: 827-32] This article was prepared by Dennis H. Black |