Beyond the two-year trial: real-World failure mechanisms of the simplify cervical disc.

backgroundCervical total disc replacement (TDR) is intended to preserve motion and reduce adjacent segment degeneration compared to anterior cervical discectomy and fusion (ACDF). The Simplify Cervical Disc (Globus Medical, Audubon, Pennsylvania), a polyetheretherketone (PEEK)-on-ceramic device with titanium-coated endplates, was approved following encouraging short-term outcomes. However, emerging registries and the Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) reports suggest an increase in device failures and revision surgeries, raising concerns about the device's long-term durability and biological compatibility.

methodsWe reviewed publicly available FDA MAUDE adverse event reports related to the Simplify disc replacement and the published literature on PEEK-on-ceramic wear mechanisms and titanium coating delamination. Representative clinical cases revised to ACDF procedures were also examined. Device bench testing data from the FDA summary were compared with real-world failure modes. Reported complications were categorized into wear, subsidence, migration, osteolysis, and revision outcomes.

resultsAnalysis of 96 MAUDE reports revealed diverse complications: osteolysis, device migration, persistent or worsening pain, and intraoperative retrieval difficulties. Histological evaluation of revision specimens demonstrated benign bone and fibrocartilage with foreign material, consistent with PEEK, titanium, and zirconia wear debris, an associated inflammatory reaction, and osteolysis. In vitro data confirm that PEEK-on-ceramic couples generate volumetric wear rates of 0.7-2.1 mm³/Mc, with titanium coating delamination further contributing to particulate load. Bench testing demonstrated mechanical adequacy under idealized conditions. However, retrieval findings highlight wear, coating failure, and osteolysis as potential failure pathways in real-world applications. Clinical outcomes after ACDF revision were favorable, suggesting effective salvage treatment.

conclusionsDespite promising early trial results, the Simplify disc demonstrates concerning failure mechanisms, including PEEK wear, titanium coating delamination, and subsequent osteolysis. The discrepancy between bench testing and retrieval analysis underscores the limitations of preclinical simulation in predicting in vivo wear. Vigilant post-market surveillance, independent registry reporting, and further long-term outcome studies are essential. Until durability is confirmed, cautious patient selection and readiness for revision remain critical in clinical practice.