Prospective, multicenter, randomized, controlled study of anular repair in lumbar discectomy: two-year follow-up.

STUDY DESIGN: Prospective, multicenter, single-blind, randomized, controlled clinical study.

OBJECTIVE: To investigate outcomes associated with repairing the anulus fibrosus after lumbar discectomy for the surgical management of herniated nucleus pulposus.

SUMMARY OF BACKGROUND DATA: In patients undergoing discectomy, the incidence of reherniation ranges from 10% to 15%. Repair of the anulus fibrosus defect after lumbar discectomy may decrease the incidence of recurrent herniation for these patients.

METHODS: A total of 750 patients were treated for herniated lumbar discs and randomly assigned in a 2:1 ratio to discectomy with the Xclose Tissue Repair System (Anulex Technologies, Minnetonka, MN) for anular repair (n = 500) or discectomy without anular repair (n = 250). Patient self-reported measures included visual analogue scales for leg and back pain, Oswestry Disability Index, and Short Form-12 Health Survey. Adverse events and subsequent reherniation surgical procedures were documented. Preoperative outcome measures were compared with follow-up visits at 2 weeks, 6 months, 1 year, and 2 years.

RESULTS: Patient symptoms were improved after surgery in an equivalent manner in both study groups. In the overall study analysis, the rate of reherniation surgery was lower for Xclose patients at all follow-up time points, but these differences were not statistically significant. In patients with predominant leg pain, there was a significant reduction in reherniation risk at 3 and 6 months postoperation for patients receiving Xclose. A positive reduction was maintained through 2 years, with a clinically relevant risk reduction of 45%, although not statistically significant. Safety was demonstrated with similar improvements in patient outcomes and no difference in reported adverse events.

CONCLUSION: Without a safe and effective method for closing the anulus fibrosus after discectomy, current practice has been to leave the anulus in a compromised state. This multicenter randomized study demonstrated that, while not statistically significant, anular repair reduced the need for subsequent reherniation surgery while retaining the benefits of discectomy with no increased risk for patients.

LEVEL OF EVIDENCE: 1.