The anterior curvature of the femur affects intramedullary nail insertion, revision prosthesis design, and the biomechanics of the proximal femur. Two previous studies, using small numbers of femurs, determined femoral curvature and showed that it was significantly greater than that of the several intramedullary nails they evaluated. In this study, the curvature of 948 femurs (474 matched pairs) was determined and compared with current intramedullary nails. The correlation of femoral curvature to age, gender, femoral size, and race was also evaluated.
Setting: Museum skeletal collections and a hospital biomechanics laboratory.
There was a large mismatch between the curvature of some current antegrade intramedullary nails and the average femur. Although this is only 1 factor affecting nail insertion, the mismatch warrants a reappraisal of these intramedullary nail designs.
Clinical Relevance: Because ease of intramedullary nail insertion and possibility of cortical comminution are determined by a number of factors including insertion point and fracture location, it appears that a decrease in radii of curvature (less straight) of current nail designs is warranted, particularly for those larger diameter nails designed for hip fracture stabilization that have greater rigidity due to design or material.
Copyright remains with the authors and publisher.
The anterior curvature of the femur affects intramedullary nail insertion, revision prosthesis design, and the biomechanics of the proximal femur. Two previous studies, using small numbers of femurs, determined femoral curvature and showed that it was significantly greater than that of the several intramedullary nails they evaluated. In this study, the curvature of 948 femurs (474 matched pairs) was determined and compared with current intramedullary nails. The correlation of femoral curvature to age, gender, femoral size, and race was also evaluated.
Setting: Museum skeletal collections and a hospital biomechanics laboratory.
There was a large mismatch between the curvature of some current antegrade intramedullary nails and the average femur. Although this is only 1 factor affecting nail insertion, the mismatch warrants a reappraisal of these intramedullary nail designs.
Clinical Relevance: Because ease of intramedullary nail insertion and possibility of cortical comminution are determined by a number of factors including insertion point and fracture location, it appears that a decrease in radii of curvature (less straight) of current nail designs is warranted, particularly for those larger diameter nails designed for hip fracture stabilization that have greater rigidity due to design or material.
Copyright remains with the authors and publisher.