Reoperations in cervical total disc replacement compared with anterior cervical fusion: results compiled from multiple prospective food and drug administration investigational device exemption trials conducted at a single site.

STUDY DESIGN

This study is based on a post hoc analysis of data collected from multiple prospective, randomized studies conducted at the same site.

OBJECTIVE

The purpose of this study was to compare the reoperation rates in patients with cervical total disc replacement (TDR) versus patients with anterior cervical fusion (ACF).

SUMMARY OF BACKGROUND DATA

One important evaluation of any new technology is the safety, including the need for future surgery. One of the potential benefits of cervical TDR compared with ACF, is the possibility of reducing or eliminating degeneration of the adjacent segment. It is also important to determine if the new technology introduces new problems, not seen with the current standard of care.

METHODS

Data were collected prospectively for patients enrolled in 1 of 6 Food and Drug Administration regulated investigational device exemption trials conducted at a single site. Results are based on 136 patients (84 TDR, 52 ACF) with mean follow-up of 55.1 months (range, 24-98 mo). Data collected included general demographics, operative details, length of follow-up, the occurrence of a reoperation, the reason for the reoperation, length of time between the index study procedure and reoperation. For this study, reoperation was defined as any surgical procedure involving the cervical spine. The reoperation rates as well as the length of time after the index surgery the reoperation occurred were compared for the TDR and ACF groups.

RESULTS

The reoperation rate in the TDR group was significantly less than in the ACF group (8.3% vs. 21.2%; P < 0.05). There was a trend for the reoperation rate attributed to adjacent segment degeneration to be significantly less in the TDR group than in the ACF group (4.8% vs. 13.5%; 0.05 <P < 0.07). In the ACF group, 4 patients (7.7%) underwent reoperation for pseudoarthrosis. Reoperations occurred significantly later in the TDR group versus the fusion group when comparing the mean number of months between index and subsequent procedures (P < 0.01). Kaplan-Meier survival analysis also found that the TDR group had a significantly longer survival period before undergoing reoperation than ACF (P < 0.05).

CONCLUSION

This study found the reoperation rate was significantly less in the TDR group compared with ACF group and that the survival time to reoperation was greater in the TDR group. Reoperations for adjacent segment changes were less frequent and occurred later in patients who were randomized to TDR compared with ACF.

LEVEL OF EVIDENCE