Preoperative psychological tests as predictors of success of chemonucleolysis in the treatment of the low-back syndrome.

Pre-injection psychological test scores, surgeon ratings, and patient biographical data were evaluated as predictors of success of chymopapain injection therapy in 130 patients who would otherwise have been treated by laminectomy. Three psychological tests were administered to each patient: the Minnesota Multiphasic Personality Inventory, the Cornell Medical Index, and the Quick Test (a measure of mental ability). In addition, the surgeons rated their patients on a five-point scale immediately after injection relative to their suitability for injection therapy and at one year relative to the objective and symptomatic results. The MMPI hysteria and hypochondriasis scales and the surgeon's rating of the psychogenic component of the patient's pain were predictive of the result of chemonucleolysis. The patient's biographical data which consisted of age, sex, marital status, occupation, and education were not related to postoperative outcome.