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

Abstract

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.

Utilization of Bone-Anchored Annular Defect Closure to Prevent Reherniation Following Lumbar Discectomy: Overcoming Barriers to Clinical Adoption and Market Access

“…The frequency of endplate changes associated with the Barricaid device is significantly higher than it is with discectomy alone and represents a serious adverse event. 42…”

Proof of concept for a biologic closure device in a rodent model with evaluation of the animals’ overall burden

“…9 Furthermore, research is poor with regard to the in uence of the Barricaid® bone implant on the vertebrae as well as a debatable bone-disk diffusion impairment of nutrients. 10,11 Currently, the Barricaid® device is not available anymore because of expired licence in Europe. 12 Likewise, soft tissue suture devices or brin/hydrogel sealant have shown controversial outcome and not all have reached clinical administration yet.…”

Angle‐ply scaffold supports annulus fibrosus matrix expression and remodeling by mesenchymal stromal and annulus fibrosus cells

“…The use of this device in patients with large herniations resulted in 52% and 62% reductions in reherniation and reoperation rates, respectively, and reduced pain compared with discectomy alone 23,24 . However, significant limitations with this device exist including the induction of endplate changes and its inability to mimic the native AF microarchitecture, mechanics, or support tissue regeneration 25,26 . Thus, there remains a critical need to develop biomaterial scaffolds that mimic the structure and function of native oAF tissue that will immediately reestablish the mechanical competency of the IVD and will support in situ tissue regeneration by endogenous AF cells (AFCs) and/or facilitate the delivery of autologous or allogeneic mesenchymal stromal cells (MSCs).…”