The compartmental approach to revision of partial knee arthroplasty results in nearer-normal gait and improved patient reported outcomes compared to total knee arthroplasty

Purpose This study investigated the gait and patient reported outcome measures of subjects converted from a partial knee arthroplasty to combined partial knee arthroplasty, using a compartmental approach. Healthy subjects and primary total knee arthroplasty patients were used as control groups. Methods Twenty-three patients converted from partial to combined partial knee arthroplasty were measured on the instrumented treadmill at top walking speeds, using standard gait metrics. Data were compared to healthy controls ( n = 22) and primary posterior cruciate-retaining total knee arthroplasty subjects ( n = 23) where surgery were performed for one or two-compartment osteoarthritis. Groups were matched for age, sex and body mass index. At the time of gait analysis, combined partial knee arthroplasty subjects were median 17 months post-revision surgery (range 4–81 months) while the total knee arthroplasty group was median 16 months post-surgery (range 6–150 months). Oxford Knee Scores and EuroQol-5D 5L scores were recorded at the time of treadmill assessment, and results analysed by question and domain. Results Subjects revised from partial to combined partial knee arthroplasty walked 16% faster than total knee arthroplasty (mean top walking speed 6.4 ± 0.8 km/h, vs. 5.5 ± 0.7 km/h p = 0.003), demonstrating nearer-normal weight-acceptance rate ( p