Objective: Among numerous minimally invasive procedures for the treatment of herniated lumbar disc disease (HLD), chymopapain chemonucleolysis has the longest history of clinical usage. Long-term studies indicated good clinical results with a low risk for patients. However, much confusion still remains about the indications. This study was conducted to evaluate the predictors of successful outcome for chemonucleolysis and to firmly establish the proper indications for this procedure.
Methods: Three thousand patients with HLD were treated with chemonucleolysis between 1984 and 1999. The clinical success rate in our series was 85%. The medical history and physical and radiological findings, including the type and direction of disc herniation, were analyzed retrospectively.
Results: The patient group with the chief complaint of leg pain achieved a better clinical outcome than the patient group with low back pain (88% versus 59%, P < 0.05). A positive straight-leg-raising test was strongly correlated with good clinical outcome (P < 0.05). Patients manifesting a soft, protruded disc had a better outcome than those manifesting diffuse bulging disc (P < 0.05). Other prognostic factors favoring a good outcome were as follows: young age, short duration of symptoms, and no bony spur or calcification on radiological study.
Conclusion: Chymopapain chemonucleolysis is a safe and effective procedure. Proper selection of patients is important for the success of treatment. We propose the following three clinical criteria (Kim's triad) for selection of patients: chief complaint of leg pain rather than back pain, positive straight-leg-raising test, and soft protruded disc.