Obesity and long term functional outcomes following elective total hip replacement

INTRODUCTION Obesity rates continue to rise and more total hip arthroplasty procedures are being performed in progressively younger, obese patients. Hence, maintenance of long term physical function will become very important for quality of life, functional independence and hip prosthesis survival. Presently, there are no reviews of the long term efficacy of total hip arthroplasty on physical function. This review: 1) synopsized available data regarding obesity effects on long term functional outcomes after total hip arthroplasty, and 2) suggested future directions for research. METHODS A literature search was conducted from 1965 to January of 2011 for studies that evaluated long term functional outcomes at one year or longer after THA in obese (body mass index values ≥ 30 kg/m2) and non-obese patients (body mass index <30 kg/m2). RESULTS Five retrospective studies and 18 prospective studies were identified as those that assessed physical function before surgery out to ≥ one year after total hip arthroplasty. Study sample sizes ranged from 108-18,968 and followed patients from one to twenty years. Total hip arthroplasty confers significant pain reduction and improvement in quality of life irrespective of body mass index. Functional improvement occurred after total hip arthroplasty among all studies, but obese patients generally did not attain the same level of physical function by the follow-up time point. DISCUSSION Uncontrolled obesity after total hip arthroplasty is related to worsening of comorbidities and excessive health care costs over the long term. Aggressive and sustainable rehabilitation strategies that include physical exercise, psychosocial components and behavior modification may be highly useful in maximizing and maintaining weight loss after total hip arthroplasty.