843 Annular Closure Device for Disc Herniation: Meta-Analysis of Clinical Outcome and Complications

Aim To assist surgeons to determine a potential approach to reduce incidences of recurrent lumbar disc herniation and assess the current devices regarding their outcomes and complications. Method Four electronic full-text databases were systematically searched through September 2017. All results were pooled utilising meta-analysis with weighted mean difference and odds ratio as summary statistics. Results Four studies met inclusion criteria. Three studies reported the use of Barricaid (ACD) while one study reported the use of Anulex (AR). A total of 24 symptomatic reherniation were reported among 811 discectomies with ACD/AR as compared to 51 out of 645 in the control group (OR: 0.34; 95% CI: 0.20,0.56; I2 = 0%; P < 0.0001). Durotomies were lower among the ACD/AR patients with only 3 reported cases compared to 7 in the control group (OR: 0.54; 95% CI: 0.13, 2.23; I2 = 11%; P = 0.39). Similar outcomes for post-operative Oswestry Disability Index and visual analogue scale were obtained when both groups were compared. Conclusions Early results showed the use of Barricaid and Anulex devices are beneficial for short term outcomes demonstrating a reduction in symptomatic disc reherniation with low post-operative complication rates. Long-term studies are required to further investigate the efficacy of such devices.

Incidence and clinical impact of vertebral endplate changes after limited lumbar microdiscectomy and implantation of a bone-anchored annular closure device

Background An annular closure device (ACD) could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). The purpose of this study was to analyze the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent reherniation. Methods This analysis includes data from a) RCT study-arm of patients undergoing LMD with ACD implantation and b) additional patients undergoing ACD implantation at our institution. Clinical findings (VAS, ODI), radiological outcome (reherniation, implant integrity, volume of EPC) and risk factors for EPC were assessed. Results Seventy-two patients (37 men, 47 ± 11.63yo) underwent LMD and ACD implantation between 2013–2016. A total of 71 (99%) patients presented with some degree of EPC during the follow-up period (14.67 ± 4.77 months). In the multivariate regression analysis, localization of the anchor was the only significant predictor of EPC (p = 0.038). The largest EPC measured 4.2 cm3. Reherniation was documented in 17 (24%) patients (symptomatic: n = 10; asymptomatic: n = 7). Six (8.3%) patients with symptomatic reherniation underwent rediscectomy. Implant failure was documented in 19 (26.4%) patients including anchor head breakage (n = 1, 1.3%), dislocation of the whole device (n = 5, 6.9%), and mesh dislocation into the spinal canal (n = 13, 18%). Mesh subsidence within the EPC was documented in 15 (20.8%) patients. Seven (9.7%) patients underwent explantation of the entire, or parts of the device. Conclusion Clinical improvement after LMD and ACD implantation was proven in our study. High incidence and volume of EPC did not correlate with clinical outcome. The ACD might prevent disc reherniation despite implant failure rates. Mechanical friction of the polymer mesh with the endplate is most likely the cause of EPC after ACD.

Incidence and Clinical Impact of Vertebral Endplate Changes after Limited Lumbar Microdiscectomy and Implantation of a Bone-anchored Annular Closure Device

Background: An annular closure device (ACD) could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). The purpose of this study was to analyze the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent reherniation. Methods: This analysis includes data from a) RCT study-arm of patients undergoing LMD with ACD implantation and b) additional patients undergoing ACD implantation at our institution. Clinical findings (VAS,ODI), radiological outcome (reherniation, implant integrity, volume of (EPC) and risk factors for EPC were assessed. Results: Seventy-two patients (37men, 47±11.63yo) underwent LMD and ACD implantation between 2013-2016. A total of 71 (99%) patients presented with some degree of EPC during the follow-up period (14.67±4.77months). In the multivariate regression analysis, localization of the anchor was the only significant predictor of EPC (p=0.038). The largest EPC measured 4.2 cm3. Reherniation was documented in 17 (24%) patients (symptomatic: n=10; asymptomatic: n=7). Six (8.3%) patients with symptomatic reherniation underwent rediscectomy. Implant failure was documented in 19 (26.4%) patients including anchor head breakage (n=1, 1.3%), dislocation of the whole device (n=5, 6.9%), and mesh dislocation into the spinal canal (n=13, 18%). Mesh subsidence within the EPC was documented in 15 (20.8%) patients. Seven (9.7%) patients underwent explantation of the entire, or parts of the device.Conclusion: Clinical improvement after LMD and ACD implantation was proven in our study. High incidence and volume of EPC did not correlate with clinical outcome. The ACD might prevent disc reherniation despite implant failure rates. Mechanical friction of the polymer mesh with the endplate is most likely the cause of EPC after ACD.

Incidence and clinical impact of vertebral endplate changes after limited lumbar microdiscectomy and implantation of a bone-anchored annular closure device

Background: An annular closure device (ACD) could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). The purpose of this study was to analyze the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent reherniation. Methods: This analysis includes data from a) RCT study-arm of patients undergoing LMD with ACD implantation and b) additional patients undergoing ACD implantation at our institution. Clinical findings (VAS,ODI), radiological outcome (reherniation, implant integrity, volume of (EPC) and risk factors for EPC were assessed. Results: Seventy-two patients (37men, 47±11.63yo) underwent LMD and ACD implantation between 2013-2016. A total of 71 (99%) patients presented with some degree of EPC during the follow-up period (14.67±4.77months). In the multivariate regression analysis, localization of the anchor was the only significant predictor of EPC (p=0.038). The largest EPC measured 4.2 cm3. Reherniation was documented in 17 (24%) patients (symptomatic: n=10; asymptomatic: n=7). Six (8.3%) patients with symptomatic reherniation underwent rediscectomy. Implant failure was documented in 19 (26.4%) patients including anchor head breakage (n=1, 1.3%), dislocation of the whole device (n=5, 6.9%), and mesh dislocation into the spinal canal (n=13, 18%). Mesh subsidence within the EPC was documented in 15 (20.8%) patients. Seven (9.7%) patients underwent explantation of the entire, or parts of the device.Conclusion: Clinical improvement after LMD and ACD implantation was proven in our study. High incidence and volume of EPC did not correlate with clinical outcome. Mechanical friction of the polymer mesh with the endplate is most likely the cause of EPC after ACD.