Cervical Disc Arthroplasty: Rationale, Designs, and Results of Randomized Controlled Trials

Background: This review outlines clinical data and characteristics of current Food and Drug Administration (FDA)- approved implants in cervical disc replacement/cervical disc arthroplasty (CDR/CDA) to provide a centralized resource for spine surgeons. Methods: Randomized controlled trials (RCTs) on CDR/CDA were identified using a search of the PubMed, Web of Science, and Google Scholar databases. The initial search identified 69 studies. Duplicates were removed, and the following inclusion criteria were applied when determining eligibility of RCTs for the current review: (1) discussing CDR/CDA prosthesis and (2) published within between 2010 and 2020. Studies without clinical data or that were not RCTs were excluded. All articles were reviewed independently by 2 authors, with the involvement of an arbitrator to facilitate consensus on any discrepancies. Results: A total of 34 studies were included in the final review. Findings were synthesized into a comprehensive table describing key features and clinical results for each FDA- approved CDR/CDA implant and are overall suggestive of expanding indications and increasing utilization. Conclusions: RCTs have provided substantial evidence to support CDR/CDA for treating single- and 2- level cervical degenerative disc disease in place of conventional anterior cervical discectomy and fusion. Clinical Relevance: This review provides a resource that consolidates relevant clinical data for current FDA- approved implants to help spine surgeons make an informed decision during preoperative planning. Level of Evidence: 5