Cervical disc arthroplasty with ProDisc-C artificial disc: 5-year radiographic follow-up results

Background Cervical disc arthroplasty is an alternative surgery to standard cervical decompression and fusion for disc degeneration. Different types of cervical disc prosthesis are used in China. The aim of this study was to evaluate the radiographic outcomes of cervical arthroplasty using the ProDisc-C prosthesis. Methods Radiographic evaluation, including static and dynamic flexion-extension lateral images, was performed at baseline and at final follow-up. Results Twenty six patients who had single-level ProDisc-C arthroplasty were followed up for a mean period of 63 months (56-76 months). The range of motion at the operated level was 9.3 degrees +/- 3.7 degrees at baseline and 7.3 degrees +/- 3.5 degrees at final follow-up, with a significant difference (P<0.05). Seventeen of 26 levels (65.4%) developed heterotopic ossification: three were classified as grade II, 13 were classified as grade III, and 1 as grade IV, according to McAfee's classification. Forty nine adjacent segments were evaluated by lateral X-ray and 18 (36.7%) segments developed adjacent segment degenerations. Conclusions ProDisc-C arthroplasty had acceptable radiographic results at 5-year follow-up. The range of motion was preserved. However, more than 60% of the patients developed heterotopic ossification.