Body mass index and lower limb diameters in total knee arthroplasty outcomes and surgical planning.

Introduction: Total knee arthroplasty (TKA) is a commonly performed surgery that can successfully treat end-stage osteoarthritis (OA). Obesity is a known risk factor for OA and its progression, but its impact on postoperative satisfaction and implant sizing remains unclear. The current study aimed to assess the association of preoperative body mass index (BMI) and lower limb dimensions with TKA component sizing and patient-reported outcomes. Material and methods: We retrospectively assessed 108 patients (43 males, 65 females) undergoing primary TKA with a Journey II BCS prosthesis, without patellar resurfacing, between January and November 2023. The mean patient age was 67.4 ±4.1 years, with a mean BMI of 29.3 ±3.9 kg/m². Patients were divided into 2 groups based on BMI: normal weight (< 25; Results: Significant differences were found between the normal-weight and overweight patients in the diameters of the femoral (15.8 ±2.1 cm vs. 17.3 ±1.9 cm, Conclusions: Body mass index affects lower limb sizes but does not predict implant sizing in TKA. Furthermore, no difference in patient satisfaction postoperatively between BMI categories was observed. The findings indicate that demographic factors may not be adequate to achieve precision in preoperative templating. Instead, surgical planning should be individualized, based on comprehensive anatomical measurements.