Clinical and Radiological Analysis of Bryan Cervical Artificial Disc Replacement for "Skip" Multi-Segment Cervical Spondylosis: Long-Term Follow-Up Results.

BACKGROUND The aim of this study was to retrospectively analyze the clinical and radiological efficacy of Bryan cervical artificial disc replacement (ADR) for "skip" multi-segment cervical spondylosis (SCS). MATERIAL AND METHODS We enrolled 49 patients with SCS treated with either Bryan cervical ADR (18 cases) or ACDF (31 cases). Each case was evaluated preoperatively and at more than 48 months postoperatively in follow-up using the JOA, NDI, and VAS. Cervical sagittal curvature, total cervical ROM, and degree of middle segments of motion were also evaluated. MRI was used to assess adjacent segment degeneration(ASD), spinal cord compression, and signal changes. RESULTS The JOA, NDI, and VAS scores in the 2 groups improved significantly postoperatively. At the last follow-up, the results of Group Bryan were better than those of Group ACDF with respect to the incidence of axial symptoms (11.1% and 45.2%, respectively), VAS, ROM, and the degree of middle segments of motion. The ROM in Group Bryan was 38.2±4.6° and in Group ACDF was 25.3±4.6°. The middle segments of motion were 8.4±2.0° in Group Bryan and 12.2±2.2° in Group ACDF. There were no patients with ASD in Group Bryan. In Group ACDF, 1 case with an internal fixation device developed dislocation, and 2 cases developed degeneration, but there was no need for reoperation. CONCLUSIONS ADR for SCS can effectively improve neurological function and retain the overall activity of the cervical, thereby reducing ASD and the incidence of postoperative axial symptoms.