天鹅记忆接骨器对骨折愈合中皮质骨胶原构筑的影响

目的 探讨天鹅记忆接骨器（SMC）对实验性骨折愈合中皮质骨胶原构筑的影响。方法 20只新西兰大白兔双侧肱骨干截骨后，随机选取一侧用SMC固定，对侧用4孔动力加压接骨板（DCP）固定，分别在术后2、4、8、16、32周时各处死4只动物取材，扫描电镜观察固定段皮质骨胶原构筑的变化。结果 SMC组在整个固定过程中，皮质骨结构与正常对照组相比无明显变化。而DCP组术后4周，胶原排列出现稀疏，局部有小吸收陷窝形成；术后8周，胶原排列紊乱，且有多个吸收腔形成；术后16周，DCP组胶原纤维出现中断；术后32周，DCP组骨质松化更加明显。结论SMC具有材料特性和几何构型上的优势，不仅对骨干不产生应力遮挡效应，而且对骨血供损伤也非常轻，故能有效防止骨质疏松的发生。

The changes of collagen architecture of cortical bone beneath swan-like memory connector fixation in rabbit fracture model

Objective To investigate the changes of collagen architecture of cortical bone beneath swan-like memory connector(SMC) fixation in rabbit fracture model.Methods Bilateral humerus of 20 rabbits were osteotomized in midshaft.One side was randomly fixed with SMC as experimental group,and contralateral was plated by the 4-hole dynamic compress plate(DCP) as control group.At the 2,4,8,16,32 weeks after operations,the cortical bone of humerus beneath fixation in 4 rabbits were harvested for scanning microscopic observation.Results No regional osteoporosis and collagen disorganization were found in SMC group during the whole experimental process.In 4 weeks after operation,the collagen architecture of cortical bone in DCP group began to show collagen fiber disorganization and resoption cavites.Along with fixation the longer,the degree of osteoporosis and bone resorption became worse gradually.Conclusion SMC has plenty of advantages in material and geometrical conformation these characteristics of SMC are beneficial not only to preventing stress shielding,but also compromise perfusion of bone less,so SMC can effectively diminish osteoporosis beneath fixation.