Predicting peak load of the femoral neck using structural parameters

The current clinical standard for diagnosing osteoporosis uses measurements of bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA). This measurement only partially explains the strength of bones and fails to incorporate other factors that alter bone quality. The aim of this study was to investigate how micro and macro cortical bone structures along the length of the femoral neck relate to the peak load of the proximal femur. Structural measurements were taken from microCT images of ten murine right femurs at ten locations along the femoral neck. These specimens were then tested to failure. The major diameter, minor diameter, cortical thickness, cross sectional area, cortical area, and cortical fraction were measured and correlated to the peak compressive load. The highest significant correlation was found using major diameter (R2 = 0.6) or cross sectional area (R2 = 0.59). Significant correlations for the major diameter were found between 40% - 60% along the femoral neck, while cross sectional area had significant correlations between 40% - 80% of the femoral neck. By combining major diameter and cortical area in a multivariable regression, R2 improved to 0.66. Understanding the contribution of cortical structure to peak load will allow for improved characterization of bone properties in both healthy and diseased bone, and provide indices for targeted imaging to better diagnosis osteoporosis