Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Institute of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Bone. 2024 May;182:117068. doi: 10.1016/j.bone.2024.117068. Epub 2024 Mar 6.
The high occurrence of distal fibula fractures among older women suggests a potential link to impaired bone health. Here we used a multiscale imaging approach to investigate the microarchitecture, mineralization, and biomechanics of the human distal fibula in relation to age and sex. Micro-computed tomography was performed to analyze the local volumetric bone mineral density and various microarchitectural parameters of the trabecular and the cortical compartment. Bone mineral density distribution and osteocyte lacunar parameters were quantified using quantitative backscattered electron imaging in periosteal, endocortical, and trabecular regions. Additionally, cortical hardness and Young's modulus were assessed by nanoindentation. While cortical porosity strongly increased with age independent of sex, trabecular microarchitecture remained stable. Notably, nearly half of the specimens showed non-bony hypermineralized tissue located at the periosteum, similar to that previously detected in the femoral neck, with no consistent association with advanced age. Independent of this finding, cortical and trabecular mineralization, i.e., mean calcium content, as well as endocortical tissue hardness increased with age in males but not females. Importantly, we also observed mineralized osteocyte lacunae that increased with age specifically in females. In conclusion, our results indicate that skeletal aging of the distal fibula is signified not only by pronounced cortical porosity but also by an increase in mineralized osteocyte lacunae in females. These findings may provide an explanation for the increased occurrence of ankle fractures in older women.
老年女性中远端腓骨骨折的高发表明其与骨骼健康受损之间可能存在关联。在此，我们采用多尺度成像方法研究了与年龄和性别相关的人类远端腓骨的微观结构、矿化和生物力学特性。我们通过微计算机断层扫描来分析骨小梁和皮质骨的局部体积骨密度和各种微观结构参数。使用定量背散射电子成像技术，在骨膜、皮质内和骨小梁区域量化骨矿物质密度分布和破骨细胞陷窝参数。此外，通过纳米压痕评估皮质硬度和杨氏模量。尽管皮质孔隙度随年龄的增长而显著增加，与性别无关，但骨小梁微观结构保持稳定。值得注意的是，近一半的标本表现出非骨样超矿化组织，位于骨膜处，类似于之前在股骨颈中检测到的情况，与年龄增长无明显关联。独立于这一发现，皮质和骨小梁矿化，即平均钙含量，以及皮质内组织硬度在男性中随年龄增长而增加，但在女性中则不然。重要的是，我们还观察到女性特有的矿化破骨细胞陷窝随年龄增长而增加。总之，我们的研究结果表明，远端腓骨的骨骼老化不仅表现为明显的皮质孔隙度增加，而且还表现为女性矿化破骨细胞陷窝的增加。这些发现可能为老年女性踝关节骨折发生率增加提供了解释。
