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Polymethylmethacrylate (PMMA) has been used to provide immediate fixation in the spine, especially in the cervical region. With its use spreading to nontumor cases and a younger patient population, its biomechanical contribution to the stability and strength of the injured spine becomes increasingly important. The present study is unique, as it provides, for the first time, results of a three-dimensional stability and flexion strength testing of a surgical specimen removed at autopsy after 7 years. Also tested, in the identical manner, is a normal specimen to provide control data. The PMMA specimen, as compared with the control, was generally found to have less motion. Its flexion strength was at par with that of the control, although it did not exhibit the initial low-stiffness region of the normal spine specimen.

Previous studies have compared the effectiveness of chemonucleolysis with surgery, but currently, no objective criteria have been correlated with the clinical outcome. The authors reviewed 28 cases where the patients had undergone chymopapain injection to determine the significance of disc herniation size, disc space height reduction, and the duration of symptoms on clinical outcome. All patients had a complete history, physical examination, and discogram, and most had pre- and post-injection computerized tomography (CT) or myelogram. Nine of the 28 patients were considered clinical failures. Seven underwent laminectomy and discectomy and were improved markedly. Two patients were advised to have surgery but refused and were considered clinical failures. The causes of failure were unknown in three patients, free fragment in two patients, and diabetic neuropathy in one. Only two patients who did well showed complete resolution of the disc deformity on repeat CT scan. The remainder still had evidence of an avascular deformity that persisted although reduced in size. The failures showed no changes in disc size. The height of the disc space was too variable to be correlated with clinical outcome. Patients who failed had a longer duration of symptoms than the ones who did well (15.1 months for failures vs. 5 months). Therefore, some reduction of disc deformity size, but not necessarily complete reduction, is necessary for a good result, and the enzyme is not as effective in patients with long-standing symptoms.

An epidemiologic case-control study to identify risk factors for acute prolapsed lumbar intervertebral disc was undertaken in Connecticut during 1979-1981. This paper focuses on nonoccupational factors of possible etiologic significance. Persons in their 30s were affected most frequently. Among surgical cases, the ratio of men to women was 1.5 to 1, while among probable and possible cases not undergoing surgery, the male to female ratio was about 1 to 1. Cigarette smoking in the past year was associated with an increased risk for prolapsed disc. The greater the number of hours spent in a motor vehicle, the higher the risk. Use of Swedish and Japanese cars was associated with a lower-than-average risk, while use of other cars was associated with a higher-than-average risk. For each type of car, older cars were associated with higher risks than newer cars. Variables that did not affect the risk for prolapsed lumbar disc in this study included height, weight, number of pregnancies, number of children, frequency of wearing shoes with high heels, smoking cigars or pipes, and participation in baseball or softball, golf, bowling, swimming, diving from a board, tennis, bicycling or jogging.

While replacement of cervical vertebral bodies may be required when they are compromised by infection, tumor, or injury, or when they impinge on the neural elements, this procedure does not add immediate stability and may cause additional problems. In this case, displacement of a large fibular graft into the spinal canal appeared to cause additional spinal cord and nerve root injury. Despite a long delay, decompression and firmly fitted and wired anterior and posterior grafts seemed to enhance the neurologic recovery and permitted rapid mobilization. The diagnostic value of computerized tomography is also demonstrated.