Adjacent segment disease requiring reoperation in cervical total disc arthroplasty: A literature review and update.

OBJECTIVE: To evaluate the difference in rate of reoperation for adjacent segment disease (ASD) between anterior cervical decompression and fusion (ACDF) and total disc replacement (TDR). METHOD: A systematic review of literature was performed using PubMed, clinicaltrials.gov, and various other search engines. Nine studies met the inclusion criteria and were used to report an estimated overall rate of reoperation secondary to ASD for both ACDF and TDR. RESULTS: Forty-six clinical trials were identified after the initial search, and 9 studies met our inclusion criteria. Although the data was not pooled due to significant variation in level of evidence and length of follow-up, the overall rate of reoperation for ASD in the TDR cohort of patients analyzed in our review was 3.1% (range: 0-7.1%) with a follow-up between 24 and 80months. In contrast, the reoperation rate for ASD in the ACDF control was 6.0% (range: 1.0-11.9%). CONCLUSION: The average reoperation rate for ASD was 3.1% for the TDR across all studies, which was lower than the reoperation rate of 6.0% in the ACDF group. Further studies and follow-up data are still needed to determine if cervical TDR preserves adjacent segment motion more efficiently than the natural history of the disease, and if it will be a durable option when compared to the already excellent results of ACDF.