Correlation of proximal femur and lumbar spine hounsfield unit with risk of osteoporotic fracture

Abstract

Fracture is a major complication of osteoporosis, however screening is not routinely carried out. CT-scan provides an opportunistic opportunity for screening, therefore this study aims to analyze the correlation the bone density on CT-scan and the risk of osteoporotic fracture. This was a cross-sectional study on patients who underwent abdominal-pelvic CT scan. Bone density was assessed with Hounsfield Unit (HU) CT-scan of the proximal femur and 3rd lumbar spine. Proximal femoral HU values were measured at the trabecular and cortical bones of the head-neck junction (HNt, HNc), femoral neck (FNt, FNc), and inter-trochanteric (ITt, ITc). The proximal femoral HU values were measured at the superior endplate, mid vertebral body, and inferior endplate. The risk of osteoporotic fracture was assessed by FRAX. Negative correlations were found between the risk of major osteoporotic fractures and HU in HNt, HNc, mid vertebral body, inferior endplate and mean proximal femoral HU. Negative correlations were also found between the risk of hip fracture and HU in HNt, HNc, FNc, ITt, ITc, superior endplate, mid vertebral body, inferior endplate and mean proximal femoral HU. The correlation shown supports the use of HU assessment of the proximal femur and lumbar spine as an opportunistic screening tool.