RESUMO
BACKGROUND: Early and intermediate results have shown that the SB CHARITÉ III total disc arthroplasty (TDA) favourably compares to spinal fusion, but is associated with fewer complications and higher levels of satisfaction. We sought to prospectively report the clinical and radiographic results of the CHARITÉ III TDA after an average of 55 months follow-up. METHODS: We conducted a prospective study of patients receiving the CHARITÉ TDA at either L4-5 or L5-S1 between April 2001 and November 2006. The primary indication for surgery was discogenic low-back pain confirmed by provocative discography. Assessment included pre- and postoperative (3, 6 and 12 mo and yearly thereafter) validated patient outcome measures and radiographic review. RESULTS: Fifty-seven of the potential 64 (89%) patients were available for complete follow-up. Their mean age was 39 (range 21-59) years. A statistically significant improvement was demonstrated between all the mean pre- and postoperative intervals for the Oswestry Disability Index, visual analogue scale for back and leg pain, and Short Form-36 health survey (p < 0.001). The mean sagittal rotation was 6.5° (range 0.5°-22.4°), and the mean intervertebral translation was 1.1 mm (range 0-2.4 mm). Subsidence of the implant was present in 44 of 53 (83%) patients with an L5-S1 disc arthroplasty. The mean subsidence was 1.7 mm (range 0-4.8 mm). CONCLUSION: The 2- to 7-year follow-up of this cohort of patients demonstrated satisfactory clinical and radiographic results in a carefully selected patient population. The radiographic assessment confirmed preservation and maintenance of motion at the replaced disc during the period of follow-up.