Prospective, Multicenter Study of Two-Level Cervical Arthroplasty With a PEEK-On-Ceramic Cervical Total Disc Replacement

STUDY DESIGN: Prospective, nonrandomized cohort analysis. OBJECTIVE: To evaluate five-year outcomes of patients treated with a polyetheretherketone (PEEK)-on-ceramic cTDR device at two levels for radiculopathy and/or myelopathy. BACKGROUND: Cervical total disc replacement (cTDR) has gained acceptance as a treatment for symptomatic cervical degenerative disc disease (DDD). Long-term follow-up studies are required to further assess clinical and radiographic outcomes, specifically for patients treated at two consecutive levels. METHODS: Patients implanted with Simplify Cervical Disc at two levels from C3 to 7 as part of a Food and Drug Administration investigational device exemption trial (NCT03123549) were contacted, consented, and prospectively followed from 36 to 60 months. RESULTS: Of 181 patients treated, 80% (144) completed five-year follow-up. Composite clinical success was 86% at 60 months versus 88% at 24 months. At 60 months, 95% had a minimum 15-point improvement in Neck Disability Index compared with 93% at 24 months. Mean neck pain improvement at 24 months (-6.1 on a 10-point numeric scale) was maintained at 60 months. Similarly, improvements in arm pain scores were also maintained from -5.7 at 24 months to -6.2 at 60 months. The cumulative five-year index level reoperation rate was 5% (1%/year) and the adjacent level reoperation rate was 2.2% (0.4%/year). Segmental range of motion was maintained at both operated segments through five years, with an average of 9.0° at superior and 8.7° at inferior levels. Bridging bone was identified in 1% of both the superior and inferior levels, 6% of superior levels only, and 6% of inferior levels only. CONCLUSIONS: This intermediate five-year follow-up study augments previously reported two-year results, supporting that the Simplify cTDR is safe and effective for the treatment of two-level symptomatic cervical DDD. Statistically significant improvements in pain and disability at two-year postoperative were maintained or improved at five years with preservation of motion and low reoperation rates at index and adjacent levels.