Bone Shape, Structure, and Density as Determinants of Osteoporotic Hip Fracture

Abstract

This article compares and combines methods for examining the external shape and the internal structure of the proximal femur with bone mineral density (BMD) to provide a classifier for hip fracture. Fifty standard pelvic radiographs were available from age-matched fracture and control groups of postmenopausal women. Femoral shape was measured using an active shape model, the trabecular structure by means of a Fourier transform. Both the shape and various structure measures were independent of BMD (P=0.16 and >0.50, respectively). Calculating the area under the receiver operator characteristic (ROC) curve (Az), each of shape (Az=0.81), the best structure measure (Az=0.79-0.93), and BMD (Az=0.79), could partially classify the fracture and control groups. However, the combination achieved almost perfect separation (Az=0.99). This pilot study shows how bone shape and structure can complement BMD measurements for investigations of fracture risk.