Analysis of heterotopic ossification in patients with medium and long term follow-up after ProDisc-C artificial cervical disc replacement

English Keywords:Artificial cervical disc replacement  Heterotopic ossification  ProDisc-C prosthesis

English Abstract:

  【Abstract】 Objectives: To evaluate the radiographic outcomes of ProDisc-C artificial cervical disc replace?鄄ment. Methods: From June 2006 to November 2008 in our hospital, 36 patients underwent single segment ProDisc-C artificial cervical disc replacement and had medium and long term follow-up, Among them, 22 cases were males and 14 cases were females; the average age was 44.7±8.1 years(27-62 years). Flexion-ex?鄄tension lateral images were performed at baseline and at final follow-up to evaluate the heterotopic ossifica?鄄tion by McAfee method. Preoperative and final follow-up segmental activity was measured using White method. Lateral X-ray image was used to evaluate the preoperative degeneration of the surgical segment by Kellgren-Lawrence classification, its relationship with heterotopic ossification(HO) at final follow-up was ana?鄄lyzed. Results: The mean follow-up time was 108.6±27.0 months. The range of motion at the operated level was 9.0°±3.6° at baseline and 6.4°±3.2° at final follow-up. 25 of 36 levels(69.4%) developed HO. According to McAfee′s classification, one level was classified as grade Ⅰ, 6 levels were classified as grade Ⅱ, 14 lev?鄄els were classified as grade Ⅲ and 4 levels as grade Ⅳ. Eleven of 25 HO were detected on the posterior margin of the prosthesis; 14 HO were detected on the anterior margin of the prosthesis. There was no signifi?鄄cant correlation between Kellgren-Lawrence classification and HO(P＞0.05). Conclusions: Heterotopic ossifica?鄄tion was common after ProDisc-C arthroplasty, which decreased the range of motion.