Mapping the Spatial Evolution of Proximal Femur Osteoporosis: A Retrospective Cross-Sectional Study Based on CT Scans

Abstract

Purpose The purpose of this study was to quantify the modifications occurring in osteoporosis at the level of the human proximal femur throughout the trabecular structure, along with the identification of certain anatomic regions preferentially affected by osteoporosis. Another goal was to map the evolution of the radiodensity of the trabecular bone as osteoporosis progresses to an advanced stage. Methods The study included CT scans (right femur) from 51 patients, out of which 40 had various degrees of osteoporosis, but no other local pathology. Ten regions of interest in two orthogonal slices have been identified and the differences in radiodensity as well as their evolution have been statistically analyzed in terms of relative and absolute changes. Results A detailed spatial map showing the evolution of osteoporosis was obtained. As osteoporosis evolved, the relative decrease in radiodensity was inversely correlated to the radiodensity of the healthy bone. In particular, the region covering the Ward triangle decreased the most, by an average 61–62% in osteopenia and 101–106% in advanced osteoporosis, while the principal compressive group was affected the least, showing a decrease by an average 14–15% in osteopenia and 29–32% in advanced osteoporosis. The absolute decrease in radiodensity was not correlated to the radiodensity of the healthy bone and was shifted to the inferior-posterior edge of the femur. Inside the femoral head, the upper region was affected the most in absolute terms, while the greater trochanter was less affected than the femoral neck. The maximum metaphyseal cortical bone density was unaffected by the progression of osteoporosis. Conclusion Significant differences were noticed in terms of the absolute and relative osteoporotic changes in radiodensity related to different anatomical regions of the human femoral bone. These differences become more pronounced as the disease progresses.

Quantitative Analysis of Primary Compressive Trabeculae Distribution in the Proximal Femur of the Elderly

“… 10 , 11 As osteoporosis progresses, the bone mass within the proximal femoral trabeculae diminishes rapidly, particularly in structures that are less mechanically stimulated. 12 , 13 Nonetheless, the primary compressive trabeculae (PCT)—a dense column of trabecular bone extending from the superior aspect of the femoral head to the medial cortex of the femoral neck—remains relatively preserved and is deemed the principal load‐bearing structure that links the femoral head with the femoral neck. 6 , 14 , 15 , 16 , 17 , 18 , 19 Consequently, exploring the PCT not only sheds light on the pathogenesis of hip fractures but also aids in refining the criteria for evaluating the effectiveness of implant selection.…”