Radiographic bone texture analysis is correlated with 3D microarchitecture in the femoral head,and improves the estimation of the femoral neck fracture risk when combined with bone mineral density

Purpose

Femoral neck fracture is a major public health problem in elderly persons, representing the main source of osteoporosis-related mortality and morbidity. In this study, we aimed at comparing radiographic texture analysis with three-dimensional (3D) microarchitecture in human femurs, and at evaluating whether bone texture analysis improved the assessment of the femoral neck fracture risk other than that obtainable by bone mineral density (BMD).

Materials and methods

Thirteen osteoporotic femoral heads from patients who fractured their femoral neck and twelve non-fractured femoral heads from osteoarthritic patients were studied using respectively (1) a new high-resolution digital X-ray device (BMA™, D3A Medical Systems) allowing for bone texture analysis with fractal parameter Hmean, and (2) a micro-computed tomograph (CT) for 3D microarchitecture. BMD was measured postoperatively by DXA in all patients in the contralateral femur.

Results

In these femoral heads, we found that fractal parameter Hmean was correlated with 3D microarchitecture parameters: bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular separation (Tb.Sp) and fractal dimension (FD) respectively (p < 0.05). Then, fractal parameter Hmean was significantly lower in the femoral heads from the fractured group than from the non-fractured group (p < 0.01). Finally, multiple regression analysis showed that combining bone texture analysis and total hip BMD significantly improved the estimation of the femoral neck fracture risk from adjusted r² = 0.46 to adjusted r² = 0.67 (p < 0.05).

Conclusion

Radiographic bone texture analysis was correlated with 3D microarchitecture parameters in the femoral head, provided accurate discrimination between the femoral heads from the fractured and non-fractured groups, and significantly improved the estimation of the femoral neck fracture risk when combined with BMD.