Intraoperative Conversion of Primary Cervical Total Disc Replacement to Fusion: Incidence and Reasons.

Study design: This was a retrospective study.

Objective: The purpose of the study was to determine the incidence and reasons of intraoperative conversion from planned cervical total disc replacement (TDR) to anterior cervical discectomy and fusion (ACDF).

Summary of background data: TDR currently offers an alternative treatment with results similar or superior to ACDF. Once individual surgeons become comfortable using a device, they will typically expand indications for its use, however, patient safety must remain at the forefront. In order to reduce reoperations, surgeons must use strict selection criteria to determine which patients are most appropriate to receive TDR. Despite those criteria, situations may arise when surgeons convert from TDR to ACDF intraoperatively.

Methods: A comprehensive surgery log was reviewed to identify cases of planned TDR converted intraoperatively to ACDF. All cases were performed at a single institution by 28 attending surgeons beginning with the first case experience in November, 2003 and ending with cases performed in November, 2023. Retrospective chart review was performed to collect demographic data and determine reasons for conversion.

Results: During the 20-year period, a total of 2,188 consecutive cases of planned TDR were examined. The total number of planned TDR levels was 2,939. The rate of intraoperative conversion of TDR to ACDF was 0.55% (12/2,188 cases), 95% confidence interval 0.30% - 0.90%. With respect to the number of operated levels, the intraoperative rate of conversion was 0.48% (14/2,939 levels), 95% confidence interval 0.30-0.80%.

Conclusion: There was a very low incidence of intra-operative conversion of cervical TDR to ACDF. However, surgeons performing this procedure should be prepared for the possibility of intraoperative conversion from TDR to ACDF and educate patients of this possibility.