超关节制动后导致骨质疏松的实验研究

EXPERIMENTAL STUDY ON OSTEOPOROSIS IN LIMB BONES AFTER IMMOBILIZATION

成年家兔24只,将左后肢屈膝30°作超关节管型石型制动。组织学检查发现制动后10天起,骨表面就出现破骨细胞性骨吸收和骨细胞性骨溶解现象。骨细胞性骨溶解活动以60~80天时较为显著,80~100天时骨外膜下破骨细胞性骨吸收和骨细胞性骨溶解活动有所缓慢,而骨内膜下和哈氏管膜下,特别是胫骨上段的骨吸收腔仍继续扩大,同时伴有大量骨内外血管的长入。结论为制动时骨吸收量多于骨形成量,故出现骨的净丧失。因有肌肉附着的部位对应力刺激减少或丧失的反应较为敏感。松质骨具有较大的物质交换面积、较活跃的代谢活动和更为丰富的血供系统,所以胫骨上段骨吸收活动甚于中段部。

In 24 rabbits,the left hind limb was immobilized in cast with knee at 30°flexion,Routine histological observations revealed that on the 10th day of immobilization,bone resorption appeared on the surface of bone.There was a decline both in the osteoclastic bone resorption in the subperiosteal region on 80th-100th day and in the osteocytic osteolysis after the 100th day.However,bone resorption kept on enlarging in the subendosteal region and under Haversian envelop,especially in the upper third of the tibia,with quite a number of extraosseous and intraosseous vessels in the enlarged resorption cavities.Various degrees of osteocytic osteolysis were observed in the whole period of immobilization and it was more apparent at the 80th-100th day.It is concluded that net bone loss after immobilization is the result of more bone resorption than bone formation.The resorptive activity in the proximal tibia,containing more spongiosa,was much more extensive than that of the middle tibia composed mainly of compact bone.