Primary hybrid THA using a polymethyl methacrylate-precoated stem: A single-center experience with a 10-year minimum follow-up.

Abstract

The high failure rate of cemented femoral components in the 1970s facilitated the improvement of the cementing technique and surface finishes such as polymethylmethacrylate (PMMA)-precoated stems, reporting a survival rate of >95% at 10 years from some studies. However, controversy persists regarding whether precoated femoral stems are associated with a longer revision-free prosthesis survival. The purpose of this study was to evaluate the clinical and radiological outcomes of PMMA-precoated femoral stems, and analyze factors associated with implant survival. We retrospectively reviewed 73 primary hybrid total hip arthroplasties performed using PMMA-precoated femoral stems. The mean age of the patients was 61 years. During the mean follow-up period of 13 years, 18 hips (24.7%) underwent aseptic loosening, and all of the loosened stems were subjected to revision surgery 8.8 years (range 4.6-15.5 years) from the index surgery. Younger age and poor cementing were significantly associated with aseptic loosening (P = 0.013 and P < 0.001, respectively). However, the aseptic loosening rate was also high at 13.1% even with a good cementing technique. In conclusion, the PMMA-precoated stem failed to show expected advantages and needs to be replaced with other surface finish stem designs. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1300-1306, 2017.