Age- and Gender-Related Femoral Bowing Analysis in the Korean Population and Features for Clinical Applications

Background and Objectives: The anterolateral bowing of the femur shows differences between races and has recently caused many clinical problems. Asians tend to have increased femoral bowing, but there is a lack of large-scale studies. We aim to identify the patterns of femoral bowing in the Korean population through comprehensive analysis and address its clinical implications. Materials and Methods: We analyzed 550 femoral radiographs from Korean patients using three different views: anteroposterior, lateral, and 15-degree internal rotation. Initial univariate analysis examined age and gender differences, followed by multivariate analysis incorporating height and weight to understand their combined effects on femoral bowing. Results: The study included 229 (41.6%) males and 321 (58.4%) females, with a mean age of 62.53 years (SD = 21.93). Initial analysis showed greater femoral bowing in females than males by 2.72° (p < 0.001) in anteroposterior views. However, multivariate analysis revealed age to be the primary significant factor affecting femoral bowing across all viewing angles (p < 0.001), while gender effects became non-significant when controlling for other variables. The AP angle regression model explained 26% of the total variance, with each year increase in age associated with a 0.12-degree increase in bowing angle. Conclusions: This study demonstrated that age is the primary factor influencing femoral bowing in the Korean population, with apparent gender differences potentially attributable to age distribution differences between groups. Anteroposterior radiographic imaging proved most suitable for assessing bowing angles. These findings provide important insights for surgical planning and implant selection, particularly in addressing potential mismatch issues in Asian populations.