The effect of chymopapain on low back pain.

One hundred and fifteen patients underwent chymopapain treatment for acute disc protrusion between 1980 and 1988. Sixty-six patients who were treated with single-level injection were reviewed retrospectively with clinical follow-up from 2 to 10 years (mean, 4.6 years). All patients met modified McCulloch criteria (not all patients had leg pain greater than back pain). The presence of pre-existing chronic low back pain (LBP) was recorded in 33 patients and compared to their present low back symptomatology and functional limitations. Patients with pre-existing chronic LBP had a success rate of 52%, whereas patients meeting all the McCulloch criteria without chronic LBP had a success rate of 52%, whereas patients meeting all the McCulloch criteria without chronic LBP had a success rate of 85%. The overall effect of chemonucleolysis on LBP demonstrated no change in 18% and a mild increase in 45% of the patients (even though they had a successful outcome). The pre-existing disc space narrowing and the postoperative change of disc space height of 33 patients assessed on lateral roentgenograms showed no correlation to the clinical response. Temporal sequential computed tomography scan assessment of 56 patients following chemonucleolysis demonstrated little change of disc herniation in the first 3 months, with only a gradual and incomplete resolution in the ensuing 12 months.