Zeng JF, et al. - Via this retrospective analysis of patients who underwent cervical disc arthroplasty with Prestige-LP Disc, researchers examined how width and depth of the inserted cervical disc prosthesis influence heterotopic ossification (HO) after cervical disc arthroplasty. Further, they investigated the relationship between clinical outcome and HO. According to the McAfee classification, there were 35 patients in the HO-group, and 67 patients in the non-HO group. Observation revealed insufficient coverage to the endplate in width and depth by some of prosthesis. HO formation could be induced by insufficient coverage of endplate in width and depth. Reduction in range of motion of the index level, but no influence on clinical outcome, was seen in correlation to HO.