Long-term Results after Weight Loss Intervention in Knee Arthroplasty Patients with Obesity.

Introduction. Obesity is a well-known problem in patients undergoing total knee arthroplasty (TKA). We have previously shown that it is feasible and safe to implement an intensive weight loss programme shortly before TKA. Preoperatively, the programme produced an average weight loss of 10.7 kg while also improving body composition and reducing cardiovascular risk factors. One year after TKA, the patients in the weight loss programme managed to maintain their weight loss, whereas no change was observed in the control group. Both groups showed major improvements in health-related quality of life (QoL) and knee function. The aim of this study was to investigate the long-term effect of a weight loss intervention in patients with obesity undergoing TKA. Methods. This was a seven-year follow-up study from a randomized controlled trial. Body weight, blood pressure and waist circumference were measured. Additionally, data on patient-reported outcome, range of knee motion (ROM), hypertension and diabetes status were collected. Results. Forty-nine patients were examined at the follow-up. No differences were found between the intervention and the control group on body weight, hypertension, diabetes, waist circumference or knee ROM. The intervention group had increased their mean weight significantly more than the control group (difference = 3.1, 95% confidence interval: 1.3-4.8). 66% had hypertension and 38% had Type 2 diabetes. Pain, function and QoL were improved for both groups. Conclusion. The patients in the intervention group were unable to maintain their preoperative weight loss when measured seven year after TKA.