The therapeutic response to treatment of lumbar
disk herniation with
chymopapain chemonucleolysis is significantly influenced by the criteria used for patient selection. Although careful clinical selection of patients reduces the frequency of treatment failure, some patients do not achieve satisfactory relief of
pain with
chemonucleolysis. In an attempt to identify objective pretreatment radiographic findings that might refine selection criteria and further reduce the failure rate of
chemonucleolysis, a retrospective correlation of pretreatment radiographs and clinical responses was made of 200 consecutive
chemonucleolysis patients. Marked improvement in
sciatica occurred in 79.9% and 79.3% of patients at early and late follow-up, respectively. There was a significantly higher response rate, however, in patients who had definite radiographic evidence of focal
disk herniation and in those patients with definite radiographic evidence of
nerve-root compression (marked nerve-root deviation, nerve-root flattening or
edema, root-sleeve
amputation) by disk material. Those patients with a preinjection disk height greater than the mean had a slightly better response rate (91.1%) than those whose disk height was smaller than the mean (80.0%). Most cases of treatment failure could be attributed to an incorrect radiographic diagnosis, treatment of patients with equivocal diagnostic studies, the presence of "free" disk fragments, and causes of
nerve-root compression unresponsive to
chymopapain.