Abstract
Obesity and lower limb osteoarthritis (OA) are amongst the commonest conditions worldwide, with increasing burden on health systems. The relationship between the two is complex. Obesity is thought to be a risk factor for OA, and OA can hinder efforts to reduce weight. Total knee replacement (TKR) is a widely used and effective management for knee OA. However, high body mass index (BMI) can complicate the surgery, which leads to some surgeons denying this operation to patients above a certain BMI. Orthopaedic surgeons have an important part in helping patients lose weight in the process of preparing for their TKR. We review the effect of high BMI on developing symptomatic knee OA, the complication rate with high BMI and TKR and the obstacles to losing weight in the presence of OA and point to areas where the orthopaedic surgeon can find support for their patients during their journey to losing weight. We review the evidence to see whether denying patients a TKR based on their BMI is justified and look into the most effective way to engage high BMI patients to improve their chance of a complication-free TKR.