Background and Aims: Obesity is an increasing problem in patients after total knee replacement. The aim of this study was to investigate whether a weight loss intervention before primary total knee replacement would improve quality of life, knee function, mobility, and body composition 1 year after surgery. Material and Methods: Patients scheduled for total knee replacement due to osteoarthritis of the knee and obesity were randomized to a control group receiving standard care or to an intervention group receiving 8-week low-energy diet before total knee replacement. Patient-reported quality of life, 6-Min Walk Test, and body composition by dual-energy X-ray absorptiometry were assessed before intervention for the diet group, and within 1 week preoperatively for both groups, and the changes in outcome from baseline to 1 year after total knee replacement were compared between groups. The number of participants was lower than planned, which might introduce a type-2 error and underestimate the trend for a better outcome after weight loss. Results: The analyses are based on a total of 76 patients, 38 in each group. This study showed major improvement in both study groups in quality of life and knee function, though no statistically significant differences between the groups were observed 1 year after total knee replacement. The average weight loss after 8-week preoperative intervention was 10.7 kg and consisted of a 6.7 kg reduction in fat mass. One year after total knee replacement, the participants in the diet group managed to maintain the weight reduction, whereas there was no change in the control group. Conclusion: The results suggest that it is feasible and safe to implement an intensive weight loss program shortly before total knee replacement. The preoperative intervention resulted in a 10% body weight loss, improved body composition, lower cardiovascular risk factors, and sustained s-leptin.

BackgroundObesity contributes much to the development of knee osteoarthritis. However, the association between obesity and outcome after knee replacement is controversial. We investigated whether there was an association between the preoperative body mass index (BMI) of patients who underwent total knee arthroplasty (TKA) and their quality of life (QoL) and physical function 3–5 years after surgery.Methods197 patients who had undergone primary TKA participated in a 3–5 year follow-up study. The outcome measures were the patient-reported Short Form 36 (SF-36) and the American Knee Society score (KSS).ResultsOrdinal logistic regression analysis (adjusted for age, sex, disease, and surgical approach) revealed a statistically significant correlation between BMI and 9 of the 14 outcome measures. For all outcome measures, we found an odds ratio (OR) of < 1. A difference in BMI of 1 kg/m2 increased the risk of a lower score from a minimum of 2% (OR = 0.98 (0.93–1.03); p = 0.5) (Mental Component score) to a maximum of 13% (OR = 0.87 (0.82–0.93); p < 0.001) (KSS function score).InterpretationOur findings indicate that TKA patients’ preoperative BMI is a predictor of the clinical effect and patients’ quality of life 3–5 years postoperatively. A high BMI increases the risk of poor QoL (SF-36) and physical function (KSS).

The physical components of QoL in patients undergoing PAO are significantly lower than the Danish population used as reference. Furthermore, the results suggest that physical function after PAO decreases with longer follow-up time. Neither the acetabular angles nor hypermobility is associated with the physical components of QoL.

Severely obese with moderate or severe preoperative knee and hip symptoms experienced a larger improvement of their QoL after a LRYGB compared to participants without symptoms before the operation.