MATERIAL and METHODS: The National Surgical Quality Improvement Project (NSQIP) Participant User Files (PUF) for the years 2005-2018 were queried for patients undergoing repeat ACDF and CDA using current procedural terminology (CPT) and International Classification of Disease (ICD)-9th version codes. We compared demographic and baseline clinical characteristics, operative characteristics, 30-day readmissions, reoperations, and complications between the two groups. We also performed multivariable analyses to assess the impact of the type of repeat procedure on outcomes of interest.

RESULTS: A total of 3,957 patients were identified, of which 182 underwent revision/removal of arthroplasty, while 3,775 underwent revision or removal of fusion. Up to 4.6% of patients (n=179) in the repeat ACDF group had a complication, compared to 0.5% (n=1) in the CDA group. The 30-day readmission rate was found to be similar between the two groups (repeat-ACDF, 3.8% (n=145), vs. repeat-CDA, 2.2% (n=4); p=0.23). Similarly, 30-day reoperation rate was also not found to be different between the two groups (repeat-ACDF, 3.9% (n=149) vs. repeat-CDA, 2.7% (n=5); p=0.39). On multivariable analysis, removal or revision ACDF was found to be only significantly associated with an increased risk of 30-day complications (OR, 8.00; 95% CI, 1.07-59.79; p=0.04).

CONCLUSION: Repeat ACDF or repeat CDA can be performed safely and are associated with optimal 30-day outcomes, comparable to those of index procedures. However, patients undergoing revision ACDF may be slightly more likely to have complications than those undergoing revision CDA. Keywords : repeat ACDF, CDA, Cervical fusion, Cervical spine, Spine, Outcomes, NSQIP, 30-day outcomes, Cervical disc replacement, Cervical disc arthroplasty