McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Calgary, Canada.
J Bone Miner Res. 2022 Oct;37(10):1963-1972. doi: 10.1002/jbmr.4663. Epub 2022 Aug 22.
Femoral neck areal bone mineral density (FN aBMD) is a key determinant of fracture risk in older adults; however, the majority of individuals who have a hip fracture are not considered osteoporotic according to their FN aBMD. This study uses novel tools to investigate the characteristics of bone microarchitecture that underpin bone fragility. Recent hip fracture patients (n = 108, 77% female) were compared with sex- and age-matched controls (n = 216) using high-resolution peripheral quantitative computed tomography (HR-pQCT) imaging of the distal radius and tibia. Standard morphological analysis of bone microarchitecture, micro-finite element analysis, and recently developed techniques to identify void spaces in bone microarchitecture were performed to evaluate differences between hip fracture patients and controls. In addition, a new approach for phenotyping bone microarchitecture was implemented to evaluate whether hip fractures in males and females occur more often in certain bone phenotypes. Overall, hip fracture patients had notable deterioration of bone microarchitecture and reduced bone mineral density compared with controls, especially at weight-bearing sites (tibia and femoral neck). Hip fracture patients were more likely to have void spaces present at either site and had void spaces that were two to four times larger on average when compared with non-fractured controls (p < 0.01). Finally, bone phenotyping revealed that hip fractures were significantly associated with the low density phenotype (p < 0.01), with the majority of patients classified in this phenotype (69%). However, female and male hip fracture populations were distributed differently across the bone phenotype continuum. These findings highlight how HR-pQCT can provide insight into the underlying mechanisms of bone fragility by using information about bone phenotypes and identification of microarchitectural defects (void spaces). The added information suggests that HR-pQCT can have a beneficial role in assessing the severity of structural deterioration in bone that is associated with osteoporotic hip fractures. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
股骨颈骨面积骨密度（FN aBMD）是老年人骨折风险的关键决定因素；然而，根据 FN aBMD，大多数髋部骨折患者并不被认为患有骨质疏松症。本研究使用新工具来研究支撑骨脆性的骨微观结构特征。使用远端桡骨和胫骨的高分辨率外周定量计算机断层扫描（HR-pQCT）对最近发生髋部骨折的患者（n=108，77%为女性）与性别和年龄匹配的对照组（n=216）进行比较。对骨微观结构进行标准形态分析、微有限元分析以及最近开发的识别骨微观结构中空隙的技术，以评估髋部骨折患者与对照组之间的差异。此外，还实施了一种新的骨微观结构表型方法来评估男性和女性的髋部骨折是否更常发生在某些骨表型中。总体而言，与对照组相比，髋部骨折患者的骨微观结构明显恶化，骨密度降低，尤其是在承重部位（胫骨和股骨颈）。髋部骨折患者在这两个部位更有可能存在空洞，与未骨折的对照组相比，空洞平均大 2 到 4 倍（p<0.01）。最后，骨表型分析显示髋部骨折与低密度表型显著相关（p<0.01），大多数患者属于该表型（69%）。然而，女性和男性髋部骨折人群在骨表型连续体中的分布不同。这些发现强调了 HR-pQCT 如何通过使用有关骨表型和微观结构缺陷（空洞）的信息来提供对骨脆性潜在机制的深入了解。补充信息表明，HR-pQCT 在评估与骨质疏松性髋部骨折相关的骨结构恶化的严重程度方面可能具有有益作用。
