A prospective controlled study of limited versus subtotal posterior discectomy: short-term outcomes in patients with herniated lumbar intervertebral discs and large posterior anular defect.

STUDY DESIGN: Prospective observational study with historical control. The prospective study population consisted of 30 patients undergoing a posterior lumbar subtotal discectomy for lumbar disc herniation. This group was compared to a historical cohort of 46 patients treated with limited discectomy alone.

OBJECTIVE: To compare clinical outcomes after limited versus subtotal discectomy for lumbar disc herniations.

SUMMARY OF BACKGROUND DATA: Large posterior anular defects found at posterior discectomy have been associated with more frequent reherniation when treated with limited discectomy (i.e., removing only extruded or loose intervertebral fragments). A trial of more aggressive discectomy (subtotal) was undertaken to determine if the rate of reherniation could be decreased with this technique.

METHODS: A total of 30 patients undergoing a posterior lumbar discectomy for lumbar disc herniation were treated with an aggressive (subtotal) resection of intervertebral disc material after removal of the extruded or protruded fragments. This group was compared against a historical cohort of 46 patients treated with limited discectomy alone. Reherniation rates and clinical outcomes were determined by independent evaluation at 6, 12, and 24 months after surgery.

RESULTS: The reherniation rate in the limited discectomy group was 18% versus 9% in the subtotal discectomy group at follow-up (P = 0.1). However, the back pain (visual analog scale) (P = 0.02) and Oswestry scores (P = 0.06) were worse in the subtotal discectomy group at 12-month follow-up. Time to return to work was longer, and pain medication usage was higher in the subtotal discectomy group at 12-month follow-up. Despite a trend toward a higher reherniation rate, the patient satisfaction at 2-year follow-up was higher in the limited discectomy group.

CONCLUSIONS: The more aggressive removal of remaining intervertebral disc material may decrease the risk of reherniation, but the overall outcome was less satisfactory, especially during the first year after surgery.