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

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.

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.

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.

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.