股骨髓腔扩大对股骨骨折及愈合影响的实验研究

Effect of Reaming Medullary Cavity on Femoral Fracture Healing

目的 探讨股骨髓腔扩大对股骨骨折局部血运及骨折愈合的影响。方法 成年新西兰兔 2 0只 ,打断股骨后分别制作扩髓与不扩髓模型 ,并用髓内钉固定。于术后 3d和 1、2、4周 ,分别注射 185MBq 99Tcm 后在放射性核素断层扫描计算机 (ECT)上进行显像 ,观察局部血供 ,并于术后 1、2、4、8周处死动物后 ,取骨痂进行组织学电镜观察。结果 股骨扩髓组99Tcm 摄取比明显下降 ,组织学研究显示扩髓组骨痂成熟缓慢。结论 股骨扩髓后早期局部血供降低 ,骨折愈合过程延迟。

Objective To study the effect of reaming medullary cavity on blood supply of femoral fracture and fracture healing. Methods Animal model was developed through breaking the femur and nailing the fracture in twenty mature rabbits, half of them with medullary reamed cavity. We injected model 185 MBq of 99 Tc m on the third day, the first,second and fourth week after operation, then conduct observation of blood supply through ECT. We also made histological and EM observation in different stages 1 week, 2 weeks, 4 weeks and 8 weeks after fracture. Results Three days after operation, the ratio of 99 Tc m uptaken amount was significantly decreased in the reaming medullary group. Immunohistochemistry study also revealed the processing of fracture healing was slower. Conclusion After reaming of medullary cavity,the blood supply of femoral fracture is reduced, and fracture healing is delayed.