骨质疏松性骨折实验模型的设计与建立

The Design and Establishment of a Model of Experimental Osteoporotic Fracture

目的 :建立较理想的骨质疏松性骨折实验模型。方法 :SD大鼠 6 0只 ,8月龄 ,雌性 ,手术方法 :切除双侧卵巢 ;术后 3个月 ,手术造成股骨中段骨折 ,进行骨圆针髓腔内固定。模型建立前后行双能X线骨密度仪 (DEXA)、组织学、放射学等动态观察。结果 :卵巢切除 3个月后DEXA检测结果与术前比较 :全身骨密度明显降低 (P <0 .0 2 ) ;子宫内膜组织萎缩变薄 ,内膜内腺体消失或萎缩、变性呈空泡状 ;软骨内成骨与膜内成骨共同参与了骨质疏松性骨折的修复 ,且以软骨内成骨为主。与一般骨折愈合方式相似 ,模型动物骨折愈合过程中 ,软骨内成骨延缓 ,骨性骨痂改建 (骨吸收 >骨形成 )加速 ,骨痂内胶原纤维疏松、排列紊乱 ,与主应力方向不一致。放射学观察模型动物骨折位置、类型统一 ,内固定后骨折断端稳定。结论 :本实验建立的骨质疏松性骨折动物模型其方法可靠 ,易于复制 ,可应用于骨质疏松性骨折的相关研究。

Objective:To establish an ideal model of the experimental osteoporotic fracture and provide a basis of experimental study of osteoporotic fracture.Method:30 femal 8-month-old SD rats were ovariectomied and all 60 rats were operated to establish model of femur fracture after 3 months.Dual-Energy X-ray Absorptionmetry(DEXA),pathologic histology and radiology were examined postoperatively.Results:DEXA demonstrated that Bone Mineral Density(BMD)of whole body decreased obviously and pathologic histology manifested that endometrium of uterus degenerated clearly 3 months after ovariectomy.In OPFM,both endochondral bone formation and intramembrane bone formation played their parts in osteoporotic fracture healing,the former played a major role.But during the healing process,endochondral bone formation delayed,while bone callus tissue remodeling accelerated(bone resorption>bone formation),collagenous fibers in callus tissue arranged loosely and irregularly and being not in consistent with the direction of the principal stress.Radiology showed position and type of femur fracture were consistent and internal fixation was stable.Conclusion:An ideal experimental model of osteoporotic fracture has been established successfully and can be applied to experimental study of osteoporotic fracture.