加锁髓内针在大鼠股骨骨折模型中的应用

目曲：通过影像学和组织学观察，骨密度（BMD）和生物力学测定，分析加锁髓内针和普通髓内针固定时大鼠股骨骨折愈合的情况。方法：3个月龄雌性Wistar处鼠50只，体重（250＋20）g，根据股骨骨折固定方式随机分为实验组（加锁髓内针组）和对照组（普通髓内针组）。每只大鼠随机选择一侧股骨，行开放性截骨制作横行骨折，并行内固定术。术后即刻、2,4周对全部大鼠进行X—ray检查，第4周断颈处死所有大鼠，取术侧股骨进行大体标本和组织学观察，BMD和生物力学检测，分析骨折愈合情况。结果：实验组比同期对照组的纤维性骨痂小，骨性骨痂大，骨性愈合时间提前；实验组骨折局部BMD高于对照组，差异有统计学意义（P〈0．01）；实验组术侧股骨的最大负荷、最大桡度均高于对照组，差异有统计学意义（P〈0．01）。结论：加锁髓内针较普通髓内针能提供抗旋转稳定性，增加骨量，促进骨性骨痂形成和骨折愈合，同时能提高骨折愈合后股骨的生物力学特性。

The use of locking femur nail in the rats femur fracture model

Objective： To investigate the healing of femur fracture fixed using locking femur nail or common intramedullary femur nail in rats. Methods： Fifty virgin female Wistar rats of 3 months old were randomly divided into two groups： experiment group （the femur fracture was fixed using locking femur nail ） and control group （the femur fracture was fixed using common intramedullary femur nail）. The X-ray, histological examination, bone mineral density and biomechanics tests were used to evaluate the bone healing. The X-ray film was performed immediately, two and four weeks after the operation. The histological examination, BMD and biomechanics tests were performed four weeks after the operation. Results： The X- ray film and histological examination showed that the bony callus was more abundant and mature in the experiment group than in the control group. The BMD was higher in the experiment group than in the control group（P〈0.01）. The biomechanics tests also showed better results in the experiment group than in the control group（P〈0.01）. Conclusion： Locking femur nail can offer stabilization environment, increase BMD, promote the fracture healing and improve the quality of callus and enhance the biomechanical properties.