Beyond Fusion: Assessing the Horizon of 3-level Cervical Disk Arthroplasty Outcomes.

Study Design: Retrospective cohort study.

Objective: To investigate postoperative medical and surgical outcomes of 3-level cervical disk arthroplasty (CDA) in comparison to 3-level anterior cervical discectomy and fusion (ACDF).

Summary Of Background Data: Cervical disk arthroplasty has emerged as a noninferior alternative to anterior cervical discectomy and fusion. However, few studies investigated the clinical outcomes of 3-level CDA. At present, CDAs beyond 2-level are performed as off-labeled procedures across the United States and can be deemed experimental by insurance companies.

Methods: Three-level CDA and 3-level ACDF patients between 18 and 84 years old from 2010 to 2020 were identified within the PearlDiver database. Ninety-day postoperative medical and surgical complications, emergency department visits, and readmission were measured. Two-year complications and 4-year rate of revisions were also studied. The Pearson χ2 test was used to assess demographics and pre-existing comorbidities. Independent effects of CDA and ACDF on the postoperative outcomes were determined with multivariable logistic regression after adjusting for demographic factors and pertinent comorbidities. PearlDiver Bellwether was used to conduct all statistical analyses via its research query interface.

Results: After matching 2901 three-level CDA patients with 14,378 ACDF patients, multivariate analysis showed that the CDA group had a significantly lower rate of 90-day dysphagia, pneumonia, wound complications, and surgical site infections. CDA patients also showed a reduced rate of 90-day ED visits and readmission. At the 2-year follow-up, CDA patients had a lower rate of instrumentation failure. At 4 years, 786 CDA patients and 3890 ACDF patients remained, and the CDA group had a lower posterior revision rate and a less overall revision rate.

Conclusions: The current study represents the largest comparative study examining clinical outcomes following 3-level CDA. CDA established itself as a safe and noninferior procedure to ACDF. However, the safety and efficacy of 3-level CDA require more long-term data to validate.