骨质疏松症患者骨小梁破骨细胞性骨吸收的扫描电镜观察

Osteoclastic resorption of trabeculae in osteoporotic fe-moral head:a scanning electron microscopic study

对７例因股骨颈囊内骨折而行人工股骨头置换术的老年妇女（平均年龄７２．４岁）的股骨头，经制备行扫描电镜检查，观察骨小梁的破骨细胞骨吸收。同年轻成年人的股骨头骨小梁相比，老年妇女股骨头的柱状骨小梁相继发生明显的骨吸收，表现为骨小梁的变细、变尖、穿孔、断裂，进而变圆钝，最后仅剩下颗状突起。骨小梁间的空隙因此明显增大。高倍镜下，可见骨小梁上卵圆形、狭长卵圆形或梭形的吸收陷窝。陷窝的大小、深浅及内容物都不一致，但都有凿缘状的边缘。陷窝四周原来具完整胶原纤维层的静止骨面也先后出现骨吸收。骨吸收过程中，无机盐可以先吸收，残剩粗糙不规则的胶原纤丝；也可以先降解胶原，使由此释放出来的无机盐结晶及不规则的骨颗粒残剩下来。最后，在陷窝内出现新形成的胶原纤丝以及新生骨组织，反映骨吸收以后的骨形成。但在老年人中骨形成现象较少见到，使骨转换处于负平衡状态。

AbstractOsteoclastic resorption was studied by scanningelectron microscopy on the trabeculae of femoral headscollected from 7 cases of aged women at an average ageof 72. 4 years,who underwent endoprosthetic replace-ment for intracapsular fracture of femoraI neck.Fe-moral head trabeculae from 3 young aduIts killed intraffic accident served as control. The trabeculae of thefemoral head formed round or roundish arch structure.The columnar trabeculae of the femoral head in theaged women showed overt osteoclastic resorption,manifesting thinning , tapering and perforation. The i-cicle-like trabeculae then became rounded, lost heightand eventually turned into a small tubbercle.As a re-suIt,the inter-trabecular space enlarged markedly.Under high magnification,on the trabeculae could bediscerned oval, narrow oval or spindle-shaped Howshiplacunae,which were various in size , depth and con-tent, but all revealed punch-out edge. Around thelacunae the collagen fibril lamella normally converingthe quiscient bone surface became resorbed sooner orlater. During bone resorption, the inorganic compo-nent of the bone matrix were first dissolved and,re-sorbed lenaving behind rough and irregular collagenfibrils; nevertheless, the collagen might be degradedand resorbed first with residual inorganic crystals andirregular bone nodules. Then emerged in the Howshiplacunae and surrounding area newly formed collagen fi-brls and bone tissuse,signifying reversal and new boneformation phases following the the bone resorptionphase. In the aged women, however, this phenomenonwas rather infrequently encountered,thereby leavingthe bone turnover aIways in a negative balance state.