CT bone density analysis of low-impact proximal femur fractures using Hounsfield units

Aim: To quantify and compare changes in bone mineral density (BMD) via CT analysis in patients with and without spontaneous femoral fractures. Materials and methods: Consecutive series of patients with CT imaging for spontaneous femoral fractures were compared to the age and gender matched controls. Bone density fixed region of interest measurements were obtained at the site of the fracture, proximally at the femoral head, and distally at the lesser trochanter in fracture patients and controls. Inter- and intrapatient comparisons were performed, including Chi-square and t-test analyses. Results: 24 spontaneous fractures and 25 controls were analyzed with no significant differences in mean age, gender, or body mass index. There were differences in the bone density between the fracture and contralateral non-fracture sides at (p = 0.0001) and distal (p < 0.0001) to the fracture. Proximal and distal bone density differences existed between case fracture and control non-fracture sites (p < 0.0001, p = 0.0001), and between the case non-fracture and control non-fracture sites (p < 0.0001, p < 0.0001). The reliability for measurements was good to excellent proximally (ICC = 0.63–0.87), moderate to excellent at the fracture site (ICC = 0.43–0.78), and fair to good distal (ICC = 0.24–0.68) to the fracture site. Conclusion: Patients with spontaneous femoral fractures exhibit lower bone density than the asymptomatic controls. Bone insufficiency is best demonstrated proximal or distal to, rather than at the fracture site.