Chemonucleolysis. Eight- to ten-year follow-up evaluation.

This study involves eight- to ten-year follow-up results of chymopapain injection for severe sciatic pain secondary to a herniating nucleus pulposus. Two hundred sixty-three of 265 patients were available for a one- to two-year examination, but only 130 responded to the survey. Forty-five percent of patients were female, 55% were male. The mean age was 40. Seventeen percent were worker's compensation cases. Of the 263 patients at one- to two-year follow-up examination, 18.6% showed excellent response, 43.7% good, 21.7% fair, 14.1% no improvement, and 1.9% were worse. Except for the 14% of cases with intractable pain, all were given three months conservative treatment prior to injection. Of the 130 patients in the long-term study, 51.5% had excellent improvement, 20% good, 12.3% fair, 12.3% no improvement, and 3.8% were worse. While 50% of these patients said that they had some pain, 72% reported very active life-styles, only 2.3% stating they were completely inactive. Only 13.1% on the patients followed for eight to ten years reported unemployment because of their low-back condition. Patients who had had surgical treatment prior to injection showed only 50% good to excellent results as compared to 73% overall. Of 43 failures treated by open surgery following injection, only five had free fragments in the spinal canal; one-third had retained intradiscal fragments; one-third had nerve root adherence of discogenic origin; the others had lateral recess stenosis. The good results generally persisted over the eight- to ten-year period. Failures appeared within the first few months.