Influencing factors for the prognosis of the patients undergoing reversion metal-on-metal hip arthroplasty for inflammatory pseudotumor

Wang Heng; Wang Yue

doi:10.3969/j.issn.2095-4344.2017.15.001

Abstract：BACKGROUND: Reversion total hip arthroplasty for inflammatory pseudotumor is little reported.OBJECTIVE: To investigate the prognosis of the reversion total hip arthroplasty for inflammatory pseudotumor and the related factors.METHODS: Eighty-one patients failed metal-on-metal hip arthroplasty were recruited, the medical history, baseline data and information of primary arthroplasty were collected, and all preoperative examinations were completed prior to reversion. The postoperative joint function was evaluated by Hospital for Special Surgery score, and the morphology of prosthesis was observed by radiology. Additionally, the serum levels of cobalt and chromium ions were detected, as well as the incidence of complications and the related factors were analyzed.RESULTS AND CONCLUSION: (1) There was a significant increase in Hospital for Special Surgery hip score and significant decrease in serum levels of cobalt and chromium ions after reversion (P=0.000). (2) The postoperative incidence of complications and secondary reversion rate was 16% and 6%, respectively. (3) Preoperative prosthesis loosening (P=0.012), tissue cirrhosis revealed on MRI (P=0.000) and the injury degree of tissue (P=0.049) were found to be related to the incidence of complications. (4) Kaplan-Meier curve showed that the survival rate of prosthesis was 88% at 30 months postoperatively. (5) These results suggest that the prognosis of reversion total hip arthroplasty is poor,which is related to the preoperative aseptic loosening, tissue cirrhosis surrounding the joint and intraoperative tissue injury, thus providing guidance for surgeons to make an appropriate operative scheme.