Assessment of Regional Structural Optimality in a 2D Synthetic Proximal Femur Model under Varying Loading Angles

Synthetic proximal femur models avoid the ethical and technical limitations of human specimens and thus serve as an effective alternative for studying the proximal femur. This structure is directly connected to the hip joint, endures complex multi-directional loads, and exhibits region-specific structural adaptations due to its unique triangular geometry. However, most previous studies have examined only global load distributions or restricted regions, limiting the understanding of regional structural optimality. Therefore, this study aims to quantitatively evaluate the load adaptability and structural optimality of the proximal femur across individual regions of interest (ROIs). Three types of 2D finite element models of synthetic proximal femur models are generated. Structural analyses are then performed by varying the loading angles of hip contact and muscle forces. Finally, the proximal femurs are divided into different sizes of grids, and the load adaptability of different ROIs was to evaluated regional structural optimality. The proximal femur exhibited region-specific differences in structural optimality and load adaptability under varying loading angles. The femoral head and greater trochanter exhibited high conformity, while the femoral neck showed consistently low conformity, demonstrating that local anatomical features play a decisive role in load adaptability. Lower model resolution reduced predictive accuracy, whereas increasing ROI size improved stability by reducing local variability. This study establishes a quantitative framework for assessing regional structural optimality in synthetic proximal femurs. The findings demonstrate anatomy-dependent load adaptability and provide foundational insight for future 3D modeling and clinical translation.