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Abstract Purpose Aseptic failure of unicompartmental knee arthroplasty (UKA) often requires revision to a total knee arthroplasty (TKA). However, outcomes following revision from UKA to TKA remain controversial. The purpose of this study was to analyze a large cohort of revisions from UKA to TKA, with emphasis on implant survivorship, clinical outcomes and radiographic results. Methods We retrospectively reviewed 118 aseptic revisions from UKA to TKA performed at a single surgical center between 2016 and 2022. Of these, 50 were required due to progression of osteoarthritis (42%), and 44 for aseptic loosening (37%). The mean age was 67 years, 65% were female, and the mean body mass index was 31 kg/m 2 . Tibial stem extensions were used in 30% of cases, augments in 9%, and a constrained implant in a single patient. The mean follow‐up was 6 years (range, 2.7–10.9). Results The 8‐year survivorship free of any re‐revision and reoperation was 94% and 92%, respectively. Progression of osteoarthritis was associated with reduced odds of re‐revision (odds ratio OR: 0.09; p = 0.025) and reoperation (OR: 0.20; p = 0.04). Knee Society Function Scores (KSS‐F) improved from 53 to 82 ( p < 0.001), with no correlation to implant type, demographics or radiographic patella height. At final follow‐up, the mean Oxford Knee and Forgotten Joint Scores were 33 and 54, respectively. The mean modified Insall‐Salvati Ratio was 1.56 preoperatively compared to 1.52 at last follow‐up ( p = 0.07). Conclusion Aseptic revision from UKA to TKA provides excellent midterm implant survivorship, clinical outcomes, and radiographic results, particularly when performed for the progression of osteoarthritis. Level of Evidence Level IV.
Ibach et al. (Sat,) studied this question.