Objective: To evaluate whether an annular closure device could be implanted safely to reduce same-level recurrent disk herniation, or attenuate disk height loss and improve the outcome after lumbar discectomy. Summary of Background Data: Same-level recurrent disk herniation, disk height loss, and progressive degeneration are common complications and sequelae after lumbar discectomy. Techniques to reduce these consequences may improve outcomes. Methods: Forty-six consecutive patients undergoing lumbar discectomy for single-level herniated disk at 2 institutions were followed prospectively with clinical and radiographic evaluations at 6 weeks and 3, 6, 12, and 24 months (control cohort). A second consecutive cohort of 30 patients undergoing 31 lumbar discectomies with implantation of an annular closure device was followed similarly. Incidence of recurrent disk herniation, disk height loss, the leg and back pain visual analog scale (VAS), and the Oswestry Disability Index were assessed at each follow-up. Results: Cohorts were well matched at baseline. By 2 years of follow-up, symptomatic recurrent same-level disk herniation occurred in 3 (6.5%) patients in the control cohort versus 0 (0%) patients in the annular repair cohort (P=0.27). A trend of greater preservation of disk height was observed in the annular repair versus the control cohort 3 months (7.9 vs. 7.27 mm, P=0.08), 6 months (7.81 vs. 7.18 mm, P=0.09), and 12 months (7.63 vs. 6.9 mm, P=0.06) postoperatively. The annular closure cohort reported less leg pain (VAS-LP: 5 vs. 16, P<0.01), back pain (VAS-BP: 13 vs. 22, P<0.05), and disability (Oswestry Disability Index: 16 vs. 22, P<0.05) 1 year postoperatively. Conclusions: Implantation of a novel annular repair device was associated with greater maintenance of disk height and improved 1-year leg pain, back pain, and low-back disability. Recurrent disk herniation did not occur in any patient after annular repair. Closure of annular defect after lumbar discectomy may help preserve the physiological disk function and prevent long-term disk height loss and associated back and leg pain.