Most patients gain weight in the 2 years after total knee arthroplasty: comparison to a healthy control group

SummaryObjectiveWhile joint arthroplasty improves the functional ability of persons with severe knee osteoarthritis (OA), the long-term effects of surgical intervention on body mass have not been evaluated. The objective of this study was to determine if a reduction in body mass index (BMI) was present following unilateral total knee arthroplasty (TKA) compared to an age-matched healthy control group who did not have surgery.MethodOne hundred and six adults with unilateral, end-stage knee OA and thirty-one persons without knee pain participated in the prospective longitudinal study. Subjects with OA underwent primary unilateral TKA and received post-operative out-patient physical therapy. Height, weight, quadriceps strength and self-perceived functional ability were measured at baseline and at a 2-year follow-up.ResultsThere was a significant interaction effect between body mass over time and subject group (P=0.017). BMI showed a significant increase over 2 years for the surgical group (P