Effects of total knee and hip arthroplasty on body weight

Patients frequently report functional and subjective improvement following total hip (THA) and knee arthroplasty (TKA), but these improvements do not correlate with decreased body weight at 1- and 2-year follow-up. The purpose of this retrospective study was to investigate changes in body weight following THA and TKA at longer follow-up than the 1- to 2-year follow-up frequently reported in the literature. A retrospective review of patients undergoing THA and TKA, as well as other commonly performed lower extremity orthopedic surgeries, was completed for January 2002 to October 2011 at a single tertiary care facility. Adults who underwent a single lower extremity orthopedic procedure during that time period were included in the study. Patients undergoing THA and TKA were analyzed for clinically and statistically significant weight changes at 1- and minimum 2-year follow-up. At a mean follow-up of 4.82 years, TKA resulted in a statistically significant decrease in mean body weight (1.47 kg; P=.0109). This finding was unique to TKA. The proportion of individuals who experienced clinically significant weight loss between the 1- and minimum 2-year follow-up was higher than the proportion of individuals who gained clinically significant weight over the same time period following THA and TKA. The results of this study suggest that clinically significant weight loss may continue for several years beyond the 1- and 2-year follow-up that is frequently reported in the literature.