Radiographic appearance and structural properties of proximal femoral bone in total hip arthroplasty patients

The relationship between the morphology of the proximal femur and the physical properties of intertrochanteric trabecular bone was assessed in 26 patients undergoing total hip arthroplasty. Significant correlations were found between ash density and (1) Singh index, (2) "calcar-to-canal isthmus ratio," and (3) a modified "morphologic cortical index." Despite this, these radiographic indices accounted for only 30% of the variability in bone density and are therefore of limited predictive value in this context. Two indices of cortical morphology were at least as effective as the Singh index in predicting cancellous bone density. Surgeons using these indices to quantify the morphology and structure of proximal femoral bone should be aware of their limitations when selecting patients for cementless arthroplasty.