Superior Outcomes for a Novel Cervical Disc Replacement Compared With Anterior Cervical Discectomy and Fusion: Two-Year Results from a Prospective IDE Study With Propensity-Matched Historical Control
David Musante, Todd Lanman, Daniel Peterson, Adam Bruggeman, Jared Ament, Ashvin Patel, Rick Sasso, J. Rafe Sales, Daniel Park, Jad Khalil, J. Alex Sielatycki, Amir Vokshoor, Armen Khachatryan, Robyn Capobianco, Neil Duggal, Luis TumialanStudy Design:
Prospective, multicenter, study with a propensity-matched historical control conducted under a US FDA IDE.
Objective:
To evaluate the safety and efficacy of the synergy disc (SD) compared to anterior cervical discectomy and fusion (ACDF) for single-level symptomatic cervical disc disease.
Summary of Background Data:
Cervical disc replacement (CDR) was developed to preserve motion while achieving outcomes comparable to ACDF. Although currently available devices are designed primarily to maintain motion, the SD is designed to provide intentional motion and restore segmental lordosis to help optimize sagittal balance. The disc is composed of titanium endplates that articulate with an ultra-high molecular weight polyethylene core with either 0 or 6° of lordosis.
Materials and Methods:
Adults with cervical radiculopathy or myelopathy at a single level and qualifying pain (VAS) and disability scores (NDI) were enrolled. The primary study endpoint was individual composite clinical success (CCS) at 24 months. CCS was achieved if a subject met the following criteria: at least a 15-point improvement in NDI score, maintenance/improvement in neurological status, and absence of the following: secondary surgical intervention on the index level, radiographic failure, and device-related serious adverse events. Secondary endpoints include change from baseline on patient-reported outcomes and treatment satisfaction.
Results:
One hundred seventy-seven patients were enrolled in the CDR group across 20 US sites; data on 192 control subjects were available. The study achieved success for both noninferiority and superiority at the two-year primary endpoint (
Conclusions:
Two-year primary endpoint results support the safety and efficacy of a CDR that incorporates motion and lordosis. Clinical success results were superior to ACDF.