Metal on Metal or Ceramic on Ceramic for Cementless Total Hip Arthroplasty: A Meta-Analysis

Background Hard bearings, metal on metal (MOM) and ceramic on ceramic (COC), have been developed to overcome polyethylene wear-related osteolysis, but comparisons between these 2 hard bearings are limited. We performed a meta-analysis to determine revision rates for (1) any reason, (2) aseptic loosening, (3) periprosthetic joint infection (PJI), and (4) recurrent dislocation between MOM and COC bearings in cementless total hip arthroplasty. Methods This analysis included 3 studies comparing COC and MOM bearings and 56 studies reporting outcomes of MOM or COC bearings. We conducted a comparison meta-analysis (with a fixed-effects model) on the 3 comparative studies and a proportional meta-analysis on the data from the 59 articles to determine a consensus. Results In the comparison meta-analysis, MOM showed higher revision rate than COC for any reason (odds ratio = 2.39, P =.046) and PJI (odds ratio = 6.21, P =.015). In the proportion meta-analysis, the MOM group showed significantly higher revision rate than COC group for any reason, aseptic loosening, and PJI. Conclusion MOM bearings were associated with a higher risk of revision for any reason and PJI than COC bearings after cementless total hip arthroplasty.