Longitudinal Prospective Long-term Radiographic Follow-up After Treatment of Single-Level Cervical Disk Disease With the Bryan Cervical Disc

BACKGROUND: Many short- and intermediate-term radiological and clinical studies on cervical arthroplasty with the Bryan Cervical Disc have been published, providing, most of the time, satisfactory results. OBJECTIVE: To prospectively assess the intermediate and long-term radiographic characteristics of disk replacement surgery with the Bryan Cervical Disc and to correlate these results with clinical outcome. METHODS: Range of motion was measured with a validated tool. Intervertebral disk degeneration was assessed with a quantitative scoring system. Heterotopic ossification was evaluated with a previously published scoring system. Device stability was investigated by measuring subsidence and anteroposterior migration. General clinical patient outcome was assessed with the Odom classification system. RESULTS: Eighty-nine patients were initially included in this prospective long-term study. One patient was reoperated on at the index level and 4 were reoperated on at an adjacent level; those patients were not further analyzed. The mobility at the treated level was preserved in >= 85% of our cases. The insertion of the prosthesis did not lead to an increase in mobility at the adjacent levels. The degeneration score increased at both adjacent levels. Heterotopic ossification was present in 34% to 39% of the patients, depending on the follow-up point. No cases of anteroposterior migration or subsidence were found. More than 82% of all patients had a good to excellent clinical outcome in the long run. CONCLUSION: The device maintains preoperative motion at the index and adjacent levels, seems to protect against acceleration of adjacent-level degeneration as seen after anterior cervical discectomy and fusion, and remains securely anchored in the adjacent bone mass in the long run. Heterotopic ossification was frequently seen. The vast majority of all patients had a good to excellent clinical outcome.