Efficiency of Complex Exercise Training on Body Composition and Functional Fitness after Total Knee Replacement in Overweight and Obese Patients with Knee Osteoarthritis

Background: Obesity is associated with an increased risk of knee osteoarthritis (KOA), which had been addressed to higher fat mass and lower lean muscle mass The incidence of receiving a total knee replacement (TKR) among obese patients increased in recent years. The limited functional mobility after TKR, which had been addressed to the deficits of muscle function and balance ability, can be improved by postoperative rehabilitation. However, it was noted that obesity exerted negative impacts on leg muscle function and postural balance control. Furthermore, it remains unclear whether post-TKR rehabilitation improves the postoperative body composition of obese patient with KOA. Purpose: To identify the training effects of postoperative rehabilitation, using elastic resistance exercise combined with balance training, on body composition of obese patients with KOA after TKR; and the relationship between changes of body composition followed post-TKR active rehabilitation and outcomes of functional mobility. Methods: Eligible participants who are overweight and obese with a body mass index ≥24 kg/m2, older than 45 years old and received a primary TKR were randomly assigned to either experimental group or control group. The experimental group received elastic resistance exercise combined with balance training 3 times a week for a total of 12 weeks, while the control group received only functional training in each admission. All outcome measures, including analysis of body composition using dual energy X-ray absorptiometry and bioelectrical impedance method, distance of functional forward reach, duration of single leg stance, timed sit-to-stand test, timed up-and-down stair test, timed 10-m walk; timed up-and-go test, and the Western Ontario and McMaster Universities Osteoarthritis Index score, and SF12, will be collected before rehabilitation, at the end of rehabilitation and 3 months after the end of rehabilitation. Discussion: Postoperative rehabilitation with a complex exercise regime exerts benefits on function outcome in obese patients KOA after TKR. Based on the fact that obesity is a risk of post-TKR function outcome and the need for obese patients with KOA to receive a TKR is gradually growing, further study should identify the training effects on body composition of obese patients with KOA after TKR. It is also important to identify the relationship between changes of body composition and outcomes of functional mobility in obese patients with KOA followed post-TKR active rehabilitation, which will help clinicians to develop post-TKR intervention models specified to obese subgroup in KOA population after TKR and enhancing the function outcome.