The PCM Cervical Disc was studied in a prospective, multicenter, randomized FDA-approved investigational device exemption (IDE) clinical trial conducted in the United States to evaluate longitudinal outcomes over 2 years comparatively between the PCM Cervical Disc and anterior cervical discectomy and fusion (ACDF) with allograft and plate. Patients with adjacent or non-adjacent prior fusion were allowed. A total of 416 patients with a degenerated cervical disc at one level from C3-C4 to C7-T1 were enrolled in the clinical trial and 403 were treated. Patients were randomly assigned to be treated either with the PCM Cervical Disc or ACDF.