Medical Devices: Evidence and Research (Sep 2019)
Annular closure device lowers reoperation risk 4 years after lumbar discectomy
Abstract
Dharmin Nanda1, Mark P Arts2, Larry E Miller3, Hans-Peter Köhler4, Jason M Perrin5, Charlotte Flüh6, Peter Vajkoczy7 1Department of Neurosurgery, Isala Klinieken, Zwolle, the Netherlands; 2Department of Neurosurgery, Haaglanden Medical Center Westeinde, The Hague, the Netherlands; 3Miller Scientific Consulting, Inc., Asheville, NC, USA; 4Department of Neurosurgery, Asklepios Westklinikum Hamburg, Hamburg, Germany; 5Department of Neurosurgery, University Clinic Mannheim, Mannheim, Germany; 6Department of Neurosurgery, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany; 7Department of Neurosurgery, Charité Universitätsmedizin, Berlin, GermanyCorrespondence: Dharmin NandaDepartment of Neurosurgery, Isala Klinieken, Dokter van Heesweg 2, AB Zwolle 8025, The NetherlandsTel +31 038 424 5000Email [email protected]: To determine whether implanting an annular closure device (ACD) following a lumbar discectomy procedure in patients with large defects in the annulus fibrosus lowers the risk of reoperation after 4 years.Methods: In a multicenter randomized trial, patients with large annular defects following single-level lumbar discectomy were intraoperatively randomized to additionally receive an ACD or no treatment (Controls). Clinical and imaging follow-up were performed at routine intervals over 4 years of follow-up. Main outcomes included reoperations at the treated lumbar level, leg pain scores on a visual analog scale, Oswestry Disability Index (ODI), and Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-36 questionnaire.Results: Among 550 patients (ACD 272, Control 278), the risk of reoperation over 4 years was 14.4% with ACD and 21.1% with Controls (P=0.03). The reduction in reoperation risk with ACD was not significantly influenced by patient age (P=0.51), sex (P=0.34), body mass index (P=0.21), smoking status (P=0.85), level of herniation (P=0.26), leg pain severity at baseline (P=0.90), or ODI at baseline (P=0.54). All patient-reported outcomes improved in each group from baseline to 4 years (all P<0.001). The percentage of patients who achieved the minimal clinically important difference without a reoperation was proportionally higher in the ACD group compared to Controls for leg pain (P=0.07), ODI (P=0.10), PCS (P=0.02), and MCS (P=0.06).Conclusion: The addition of a bone-anchored ACD following lumbar discectomy in patients with large post-surgical annular defects reduces the risk of reoperation and provides better long-term pain and disability relief over 4 years compared to lumbar discectomy only.Keywords: annular closure device, annulus fibrosus, disc herniation, lumbar discectomy, randomized controlled trial, reoperation, sciatica
