Comparison of Complications Following Revision of Metal-on-Metal Versus Metal-on-Polyethylene Total Hip Arthroplasty.

The aim of this study was to examine the clinical characteristics of patients who required revision and the rate of early complications after revision for metal-on-metal total hip arthroplasty (MOM THA) and metal-on-polyethylene total hip arthroplasty (MOP THA). Matched cohorts were selected by retrospective review from a single-center database of revision THAs for failed MOM and MOP THAs from 2010 to 2014. A total of 140 hips in 140 patients comprised the study population; 39 revisions were performed for failed MOM THAs (MOM group), and 101 revisions were performed for failed MOP THAs (MOP group). Data included patient demographics, reason for revision, type of revision procedure, any complication within 90 days after surgery, admission type, and discharge disposition. Primary diagnosis, time from primary THA to revision, operative time, blood loss, and length of stay were reviewed. The analysis showed the time from the index primary procedure to first revision was earlier (P=.01) in the MOM group despite no significant intergroup differences in age, gender, primary diagnosis, or body mass index. Surgical morbidity, as indicated by operative time, blood loss, and length of stay, was lower in the MOM group. The stem was retained more often in the MOM group. There was no significant difference between the groups in overall complication rate. These findings indicate that when performed at an earlier time period before extensive soft tissue reaction to metal ions, revision following MOM THA is not associated with an increased complication rate compared with revision following MOP THA. [Orthopedics. 2017; 40(1):e164-e169.].