Why are total knee arthroplasties being revised?

Despite technical improvements, revision rates for total knee arthroplasties (TKAs) remain high. Our goal was to report the reason(s) for revision TKA in a large, current, multicenter series and compare those reasons with previously published reasons. We retrospectively identified 820 consecutive revision TKAs (693 patients, 2000-2012) from our 3 centers and recorded the primary reason for the revision. The top seven reasons for the revision were aseptic loosening (23.1%), infection (18.4%), polyethylene wear (18.1%), instability (17.7%), pain/stiffness (9.3%), osteolysis (4.5%), and malposition/malalignment (2.9%). Comparison with previously published reasons showed fewer TKA revisions for polyethylene wear, osteolysis, instability, and malalignment. These changes may represent improvements in surgical technique and implants.