Outcomes of the Bryan cervical disc replacement: fifteen year follow-up.

ABSTRACT

BACKGROUND: The CTDR is a technique that treats cervical disc degenerative disease. Initial shorter-term studies showed good clinical and radiological results. PURPOSE: To assess the clinical and radiological results of Bryan cervical disc replacement (Medtronic Sofamor Danek Inc., Memphis, TN) at 15-year follow-up. RESULTS: This prospective study included 20 patients who underwent 22 CTDR, comprising a single-level procedure in 14 patients and two-level procedures in six patients. The mean follow-up period was 15.5 years. The mean age at the intervention was 46.2 years (range 26-65 years). Two patients needed re-operation for recurrence of symptoms. According to Odom's criteria, 80.0% (16 of 20 patients) had excellent outcomes, VAS for neck pain was 2.6 (0-10), for shoulder/arm pain it was 1.8 (0-7), and NDI at the final follow up was 14.9. The SF-12 PCS was 46.1, and SF-12 MCS was 51.9. Mobility was maintained in 15 of the 22 (68.2%) operated segments, range of motion (ROM) of prostheses were 9° ± 3.9° (range 4-15°). The prostheses were positioned in kyphosis in 14 of 22 levels (63.6%). There was a positive correlation between the kyphosis of the prosthesis and the occurrence of heterotopic ossification (HO), and their grade (ρ = 0.36, CI 95%[-0.68; 0.07]). HO had developed at 12 of the 22 levels (54.5%) and upper adjacent segment degeneration in 11 of 18 of patients (64.7%). All these results were not significantly different to outcomes at 8 years follow-up. CONCLUSION: In a cohort of 20 patients with 15-year clinical and radiological follow-up, the Bryan CTDR has demonstrated a sustained clinical improvement and implant mobility over time, despite a moderate progression of degenerative processes at the prosthetic and adjacent levels.