The safety of the PCM Cervical Disc was assessed by comparing the adverse events, any additional surgical procedures, and the neurological outcomes to those in the ACDF control group. The effectiveness of the PCM Cervical Disc was assessed by evaluating patients' pain and function outcomes using a standard questionnaire, the Neck Disability Index (NDI), the severity of neck and arm pain based on a Visual Analog Scale (VAS) assessment, quality of life using a standard questionnaire, the Short Form-36 (SF-36), as well as a patient satisfaction questionnaire compared to the ACDF control group. In addition, the patients were evaluated using radiographic evaluations, including spinal range of motion, spinal disc height, device displacement or migration, spinal fusion status, and heterotopic ossification (abnormal bone formation).