Injection of collagenase in the treatment of herniated lumbar disk. Initial clinical report.

Twenty-nine patients with persistent, low back and sciatic pain received intradiscal collagenase at a single abnormal disk space after two months of conservative therapy and two weeks of additional bed rest. Complete pain relief was achieved in six patients (21%), notable relief in 12 (42%), moderate in six (21%), and slight in one. Four patients (14%) who obtained no improvement by enzyme injection recovered after extruded disk fragments were removed from the spinal canal during a later operation. Pain relief after collagenase injection took place gradually over a two- to three-week period and was associated with some early backache. Improvement then continued at a slower rate for two to three months. There were no adverse effects of enzyme therapy. Injected disk spaces usually showed radiological narrowing.