The two-year results from a Level 1, randomized superiority study were published in The Spine Journal. Results from this landmark clinical study, that includes 554 patients from 6 countries, demonstrate superior outcomes when treating patients with large annular defects with Barricaid Annular Closure compared to discectomy alone.
Background context: Patients with large annular defects following lumbar discectomy for disc herniation are at high risk for symptomatic recurrence and reoperation.
Objective: To determine whether in a large defect subpopulation, a bone-anchored annular closure device in addition to lumbar microdiscectomy resulted in lower reherniation and reoperation rates plus increased overall success compared to lumbar microdiscectomy alone.
Study Design: Multicenter, level I, randomized superiority study.
Patient Sample: Patients with symptoms of lumbar disc herniation for at least 6 weeks with a disc height ≥5mm and large annular defect (6-10mm width) following lumbar microdiscectomy.
Outcome Measures: The prospectively defined co-primary end points were recurrent herniation and a composite end point consisting of patient-reported, radiographic, and clinical outcomes. Study success required superiority of annular closure on both end points at 2 years follow-up.
Methods: 554 patients undergoing lumbar microdiscectomy with additional bone-anchored annular closure device (n=276 participants) or lumbar mircrodiscectomy only (control; n=278 participants).
Results: Both co-primary end points of the study were met, with (a-)symptomatic recurrent herniation (50% vs. 70%, P<0.001) and composite end point success (27% vs. 18%, P=0.02) favoring an annular closure device.
Clinically meaningful end point:
- The frequency of symptomatic reherniation was lower with Barricaid (12% vs. 25%, P<0.001).
- Index-level reoperations were les frequent with Barricaid (9% vs. 16%, P=0.01).
- The frequency of reoperations to address recurrent herniation was 5% with annular closure device and 13% in controls (P=0.001).
Endplate changes were more prevalent in the annular closure device group (84% vs. 30%, P<0.001), however no correlation with any symptom or clinically adverse event was observed.
Scores for back pain, leg pain, Oswestry Disability Index, and health-related quality of life at regular visits were comparable between groups over 2-year follow-up.
Conclusion: In patients at high risk of herniation recurrence following lumbar microdiscectomy, annular closure with a bone-anchored implant lowers the risk of symptomatic recurrence and reoperation. Additional study to determine outcomes beyond two years with a bone-anchored annular closure device is warranted.