老年女性股骨颈皮质哈氏系统的破骨细胞性骨吸收的扫描电镜观察

Osteoclastic resorption of Haversian system of femoralneck cortex in aged women

７例老年女性骨质疏松患者（平均年龄７２．４岁），因股骨颈囊内骨折而行人工股骨头置换手术时，取骨折部位的股骨颈皮质骨，修成横切面标本。在扫描电镜下观察。发现皮质骨中，圆形、卵圆形的哈氏管经历着扩大的变化。扩大哈氏管的壁面呈现众多吸收陷窝，反映破骨细胞性吸收。哈氏管的骨吸收及扩大，最先发生在皮质骨的内侧部分，并形成巨大的、圆形或卵圆形的空隙，从而使其内侧部分变疏松（松质骨化）。以后，骨吸收及扩大又相继发生在皮质骨的中间部分及外侧部分的哈氏管，使整个皮质骨松质骨化。与此同时，已成为松质骨的部分也由内向外开始吸收，使皮质骨变薄。松质骨化及变薄的股骨颈皮质骨丧失其结构强度，即使在轻微的外力下也容易发生骨折。

AbstractOsteoclastic resorption was studied with scanningelectron microscope on cross sections of cortical boneof femoral neck collected from 7 aged women with anaverage age of 72 4 years,who underwent endOpros-thetic replacement for intracapsular hip fracture. Thecortical bone sections revealed enlargement of theHaversian canals. On the inner linings of the enlargedcanals there were many oval-shaped resorption lacu-nae, reflecting osteoclastic resorption of the Haversiansystems.The osteoclastic resorption with subsequentenlargement of the Haversian canals into round or ovalcavities took place first over the inner portions of thecortical sections,thereby rendering these areas porotic(cancellization).These processes of the Haversian sys-tem and canals then gradually emerged over the centraland eventually over the outer areas of the corticalbone, and the entire cortical bone became porotic。 Inthe meanwhile,the inner porotic portion of the cortexturned into trabeculae (trabecularization)and becamegradually resorbed, resulting in thinning of the medialcortex。 Cortical cancellization, trabecularization andthinning so compromised the material strength of thefemoral neck that fracture would ensue even with triv-ial injury.