Patient-reported outcomes after revision of metal-on-metal total bearings in total hip arthroplasty

Abstract Background Failure of metal-on-metal (MOM) total hip arthroplasty (THA) bearings is often accompanied by an aggressive local reaction associated with destruction of bone, muscle and other soft tissues around the hip. Little is known about whether patient-reported physical and mental function following revision THA in MOM patients are compromised by this soft tissue damage, and whether revision of MOM THA is comparable to revision of hard-on-soft bearings such as metal-on-polyethylene (MOP). Methods We identified 75 first-time MOM THA revisions and compared them to 104 first-time MOP revisions. Using prospective patient-reported measures via the Veterans RAND-12, we compared physical (PCS) and mental function (MCS) at pre-operative baseline and post-operative follow-up between revision MOM THA and revision MOP THA. Results PCS did not vary between the groups pre-operatively and at 1 month, 3 months, and 1 year post-operatively. MCS pre-operatively and 1 and 3 months post-operatively were lower in patients in the MOM cohort compared to patients with MOP revisions (Baseline 43.7 vs. 51.3, P