Cervical arthroplasty with Bryan disc: 10-year follow-up results

English Keywords:Cervical spondylosis  Cervical disc arthroplasty  Long-term follow-up  Heterotopic ossification  Reoperation

English Abstract:

  【Abstract】 Objectives: To evaluate the radiographic and clinical outcomes of Bryan cervical disc arthroplasty at 10 years follow-up. Methods: Sixty patients with complete clinical and radiographic data were included in this study. The mean follow-up period was 124.0±8.3 months(117-150 months). 47 patients underwent single-level arthroplasty and 12 underwent arthroplasty at two levels. 1 patient underwent arthroplasty at three levels. 15 of the 60 patients presented with radiculopathy and 41 patients with myelopathy, 4 patients were with combined radiculopathy and myelopathy. Clinical evaluations included mJOA score, VAS score, etiology and surgical strategy of reoperations. Radiographic evaluations included heterotopic ossification according to McAfee′s classification and the range of motion on dynamic X-rays at baseline and at final follow-up. Results: The mJOA score of the patients with myelopathy was 13.4±2.2 at baseline and 15.8±1.1(P＜0.05) at final follow-up. The arm VAS score of the patients with radiculopathy was 5.7±2.2 at baseline and 0.7±0.9(P＜0.05) at final follow-up. The neck VAS score of the patients with radiculopathy was 4.7±2.2 at baseline and 1.0±1.0(P＜0.05) at final follow-up. The mJOA score of the patients with combined radiculopathy and myelopathy was 13.3±3.6 at baseline and 15.4±1.1 at final follow-up. The arm VAS score was 4.3±2.6 at baseline and 1.0±1.4 at final follow-up. The VAS neck score was 2.8±1.5 at baseline and 2.5±1.9 at final follow-up. 1 patient received reoperation due to adjacent segment disease. 6 patients received revision surgeries at the index level for recurrent radiculopathy or myelopathy caused by heterotopic ossification (The initial surgeries included 1 cases of arthroplasty at two levels and 5 case of single-level arthroplasty; 3 levels were classified as grade Ⅲ heterotopic ossification and 4 levels as grade Ⅳ before the reoperations). On X-ray examination, the range of motion at the operated level was 7.0°±2.9° at baseline and 4.6°±4.1° at final follow-up(P＜0.05). Heterotopic ossification was observed in 53(71.6%) levels. According to McAfee′s classification, 5 levels were classified as grade Ⅱ, 21 levels were classified as grade Ⅲ and 27 levels as grade Ⅳ. Conclusions: Cervical arthroplasty with Bryan cervical disc prosthesis resulted in fine clinical outcomes at long-term follow-up. The rate of heterotopic ossification was high after Bryan disc arthroplasty and heterotopic ossification accounted for most of the reoperations.