Long-Term Results after Cervical Disc Replacement using Bryan Prosthesis

Study Design: Retrospective clinical study. Objective: To study the outcome of cervical disc replacement with a Bryan prosthesis in 60 to 91 months follow-up duration through analyzing the motion of index segments and associated heterotopic ossification (HO), and adjacent segment degeneration using their motion, patient satisfaction, and pain as indicators. Summary of Background Data:Cervical disc replacement is considered to be equivalent if not superior to discectomy and fusion because it allows for decompression while maintaining segmental motion and has the potential to minimize adjacent segment disease. However, long-term results of motion and degeneration of adjacent segments after cervical disc replacement are rare. Methods: Data of 47 patients with cervical disc prolapse, treated with cervical disc replacement with a Bryan disc between January 28, 2002 and October 31, 2003 in the orthopadische Klinik Markroningen, Germany were analyzed. Cobb angles of the exchanged segment, and the adjacent segments were measured on pre- and postoperative radiographic pictures. The grade of heterotopic ossification was examined. The postoperational functionality of the cervical spine was examined via active range of motion. Patients' satisfaction and pain were assessed using; the neck disability index (NDI), Odom criteria, and visual analog scale (VAS). Results: At follow-up no postoperative complications or revision were recorded. No HO formation was present in 34 patients (72.3%), grade I and grade III HO was present in 10 patients (21.3%) five of each grade. Segmental fusion (grade IV) was observed in three patients (6.4%). Most patients showed improved motion and high satisfaction. Mean NDI was 12.3% (SD = 13.12). Mean VAS score was 1.8 (SD = 2.1). Using Odom criteria all patients were classified as a clinical success. Conclusions: Preserving stability (as a nonresorbable stable place holder) and the goals of decompression, cervical disc replacement preserved motion, and decreased related degeneration clinically and radiologically.