Is BMI Outdated in TKA Patient Selection? Assessment of the Impact of Pre-tubercular Subcutaneous Tissue Thickness and the Risk of Postoperative Infection Following Total Knee Arthroplasty

While Body Mass Index (BMI) is currently used as a primary tool for risk stratification in patients undergoing Total Knee Athroplasty(TKA), its limitations raise concerns regarding its accuracy and fairness in guiding surgical decision-making. In particular, reliance on BMI alone may lead to the exclusion of patients who could safely benefit from surgery, while failing to identify others at increased risk due to unfavourable local anatomical factors. Pre-tubercular subcutaneous fat thickness (PTFT) offers a simple, reproducible, and anatomically relevant measurement that directly reflects the soft tissue envelope at the operative site. As such may provide a more clinically meaningful assessment of infection risk than BMI. This study aims to evaluate the association between PTFT and postoperative infection following TKA. By doing so, it seeks to determine whether PTFT could serve as an adjunct or alternative risk stratification tool in clinical practice. The findings of this study have the potential to inform a more individualized approach to patient selection and preoperative counselling, improving shared decision-making and resource utilisation.