Anatomical Variability of the Proximal Femur: A Morphometric Study Relevant to Orthopedic Implant Design

Objective: Proximal femur morphometry plays a crucial role in fracture management and hip arthroplasty by affecting implant fit, biomechanics, and surgical outcomes. Therefore, the utilization of anatomical data reflecting inter-individual variability is essential for optimizing implant design and minimizing implant-bone mismatch. This study aimed to evaluate proximal femoral morphometry and provide data relevant to implant design. Methods: A total of 73 unpaired dry femurs of unknown age and sex (43 right, 30 left) were analyzed. Measurements included femoral length, neck-body angle, and femoral head and neck dimensions. All measurements were independently performed by two anatomists and repeated using a tape measure, a digital caliper, and a protractor. Interobserver and intra observer reliabilities were assessed using intraclass correlation coefficients (ICC). Statistical analyses were performed, including descriptive statistics, pairwise comparisons, and correlation analyses. Results: Measurement reliability ranged from good to excellent (ICC: 0.749-0.999). Mean femoral length was 43.7±3.0 cm, and mean neck-body angle was 126.0°±4.6°. No significant side differences were observed for femoral length, femoral head, or femoral neck dimensions; however, the neck-body angle differed significantly (p<0.001). The correlation analysis revealed positive associations among parameters of the femoral head and neck. Femoral length showed strong correlations with head dimensions, whereas the neck-body angle demonstrated no significant correlations with other parameters. The lack of age and sex data should be considered when interpreting these findings. Conclusions: The proximal femur exhibits substantial morphometric variability. These findings provide preliminary data that may contribute to the existing literature and help inform the design of future implants and prostheses.