High rate of infection after aseptic revision of failed metal-on-metal total hip arthroplasty

Background: Evidence suggests some metal-on-metal (MOM) THAs have higher rates of failure and subsequent revision than other bearing surfaces. However, there are few studies demonstrating how these patients fare after revision. Questions/purposes: We asked: (1) What is the short-term survivorship of revision THA in patients whose index THAs employed MOM bearings? (2) What are the causes of failure of revision THA in these patients (ie, what are the indications for repeat revision)? (3) What are the most common complications after revisions of MOM THAs? Methods: We identified 37 patients (24 women, 13 men; mean age, 55 years; 37 hips) revised for aseptic failure of primary stemmed MOM THAs. Reasons for revision included pain with loose components (n = 19), adverse reaction to metal debris (n = 8), periprosthetic fracture (n = 4), impingement (n = 3), dislocation (n = 2), and pain of unknown origin (n = 1). Minimum followup was 24 months (mean, 33 months; range, 24-81 months) postrevision, but 11 were not seen in the last 2 years as our routine followup is at 2 and 5 years. Clinical histories were reviewed for reasons for failure of the MOM THAs and complications associated with revision surgery. Results: Survivorship free from further revision for any cause was 95% at 24 months and 92% at latest followup (24-81 months). There were three repeat revisions, all for periprosthetic infection, and all were treated with two-stage reimplantation. No other complications were observed. Conclusions: We observed a higher-than-expected rate of infection after revision of MOM THAs. The infection rate was higher in this report than in an earlier series looking at revision THAs for other indications at our institution. As revision of MOM THA becomes more common, it will be important to continue monitoring postrevision outcomes and providing treatment strategies to mitigate complications for these patients. Level of Evidence: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.