骨质疏松性头颈型股骨颈骨折股骨头的显微CT观察

Micro-CT Observation of Trabecular Bone of Femoral Head in Osteoporotic Femoral Neck Fracture

目的对骨质疏松性头颈型股骨颈骨折的股骨头标本的结构性薄弱区展开研究,为股骨颈骨折发生机制的相关研究提供理论依据。方法对首都医科大学附属北京朝阳医院收集的头颈型股骨颈骨折的6个股骨头标本进行显微CT扫描,其中男性标本5个,女性标本1个;年龄68~82岁,平均(73.17±4.92)岁;左侧3个,右侧3个。在股骨头内周围区和股骨头外上区、骨折线最下区选取兴趣区进行重建和分析,比较骨形态结构参数。结果股骨头外上区与股骨头内周围区相比,骨小梁间隔、骨小梁厚度、骨小梁数量、结构模型指数、骨小梁连接密度、组织骨密度、体积骨密度、骨体积分数、骨表面积体积比,差异均无统计学意义(P>0.05)。三维重建图像显示股骨头外上区骨小梁间隔增加、厚度减少,骨小梁发生断裂、变细甚至消失,骨小梁结构更接近杆状。股骨颈骨折线最下区与股骨头内周围区相比,骨小梁厚度、骨密度以及骨体积分数增高,骨表面积体积比、结构模型指数减低,差异具有统计学意义(P<0.05),骨小梁间隔、数量以及骨小梁连接密度比较差异无统计学意义(P>0.05)。三维重建图像显示,与周围区相比,骨折线最下区内骨小梁厚度明显增加,骨小梁结构更接近板状。结论股骨头外上方结构存在一定程度薄弱,可能与骨折易由此处发生有关。骨折线最下方股骨颈中段内侧未显示骨质减弱。

Objective To investigate the regions of structural vulnerability within the femoral head of patients suffering from osteoporotic femoral neck fractures,aiming to contribute insights into the underlying mechanisms of such fractures and inform future research endeavors.Methods Utilizing micro-CT scanning technology,we examined six femoral head specimens procured from patients[(5 males and 1 female,aged 68~82 years,mean age(73.17±4.92)years;3 left-sided and 3 right-sided)]with confirmed osteoporotic femoral neck fractures,admitted to Beijing Chao-Yang Hospital,Capital Medical University.High-resolution imaging enabled us to reconstruct and comprehensively analyze the bone microstructure in three distinct yet critical areas:The peripheral region of the femoral head,the supralateral quadrant of the femoral head,and the inferior aspect proximal to the fracture site within the femoral neck.Subsequently,we conducted a comparative analysis of bone structural parameters across these regions to identify potential areas of weakness.Results In comparing the supralateral region of the femoral head to its peripheral zones,no statistically significant variations were observed in trabecular separation,thickness,number,structural model index,trabecular connectivity density,tissue bone mineral density,volume bone mineral density,bone volume fraction,or bone surface/volume ratio(P>0.05).However,three-dimensional reconstructions of the supralateral area revealed increased trabecular separation,decreased trabecular thickness,and a noticeable decrease in trabecular number,accompanied by a more rod-like trabecular structure,indicative of structural weakening.Contrastingly,the lowest region of the femoral neck fracture demonstrated statistically significant increases in trabecular thickness,bone mineral density,and bone volume fraction compared to the peripheral regions,while the bone surface/volume ratio and structural model index decreased significantly(P<0.05).Despite this,trabecular separation,number,and connectivity density did not exhibit statistically significant differences(P>0.05).Three-dimensional reconstructions highlighted that the trabecular thickness in the lowest region of the fracture was notably thicker than in the peripheral zones,exhibiting a more plate-like trabecular structure.Conclusion The supralateral region of the femoral head is a potentially weak structure that may be prone to fracture during sideways falls.There was no apparent bone weakness at the bottom of the fracture site in the medial aspect of the femoral neck.