Does the choice of outcome scale influence prognostic factors for lumbar disc surgery? A prospective, consecutive study of 121 patients.

From January to June 1994, we operated conventionally on 121 consecutive hemiated lumbar disc patients as part of a prospective study. We analysed general data, case histories, neurological findings on admission and all data from imaging investigations and therapy. In addition, all patients received a questionnaire based on the Low Back Outcome Score. Most of the patients (93%) were followed-up for 1 year postoperatively in the same manner. On the Prolo Scale, we obtained a good result in 70%; 76% had a good Low Back Outcome Score. Predictive factors are different for different outcome scales. The preoperative duration of pain, the preoperative duration of paresis and smoking seem to be general predictive factors.