Early Cases of Single-Level Cervical Total Disc Replacement in Japan-Short-Term Safety Assessment Using Registry Data

Total disc replacement (TDR) using Mobi-C^Ⓡ and Prestige LP^Ⓡ was approved in Japan in 2017. To ensure effective surgical outcomes with TDR, the Japanese TDR guideline was established before its clinical use, and a registry system was developed to monitor the safety of early cases in Japan. This study assessed complications associated with TDR during the early post-approval period using this nationwide registry to evaluate the short-term safety of single-level TDR.

Data from the nationwide registry covering postoperative 2-year surveillance were analyzed for single-level TDR performed during the post-marketing surveillance period in Japan. The database included patient characteristics, surgical details, complications, and reoperations. Complication and reoperation rates were analyzed for the perioperative period during hospitalization and the postoperative period after discharge.

In total, 332 patients were enrolled in this study, and 271 patients completed the 2-year follow-up (81.6%). Mobi-C^Ⓡ and Prestige LP^Ⓡ were used in 158 and 113 patients, respectively. Perioperative complications included hematoma (n=3) and airway obstruction (n=1). Three (1.1%) patients with hematoma underwent reoperation in the perioperative period during hospitalization. Overall, 20 (7.4%) patients experienced complications after discharge up to 2 years postoperatively, including recurrences of neurological symptoms (n=9), implant migration (n=2), implant subsidence (n=7), and others (n=3). Two (0.7%) patients who experienced a recurrence of neurological symptoms underwent additional posterior foraminotomy within 2 years postoperatively. One (0.4%) patient underwent implant removal and conversion to fusion due to implant subsidence.

The overall complication and reoperation rates of TDR were relatively low: 1.5% and 1.1% in the perioperative period during hospitalization and 7.4% and 1.1% within the 2-year postoperative period after discharge, respectively. TDR achieved favorable outcomes with acceptable complication rates when performed under appropriate surgical indications.