摘要
作者以镍钛形状记忆合金制成锯齿臂环抱内固定器，与不锈钢接骨板进行实验比较。１５只犬作两侧股骨干横行截骨，一侧以环抱器、另侧以接骨板作内固定。术后４、８和１２周作Ｘ线摄片、光镜及透射电镜观察显示，两种内固定方法的骨折愈合与骨痴改建进程相似，但板下近截骨区的皮质骨改建活动却具明显差异。环抱侧板下皮质骨８周后出现退变相骨细胞，１２周后退变相骨细胞逐渐增多。而钢板侧术后４周即出现退变相骨细胞，８周后该细胞大量自溶。说明钢板侧板下皮质骨骨细胞时相变化比环抱侧出现早且剧烈，骨吸收程度也更为严重。作者认为，与钢板内固定相比，环抱器弹性模量较低，且在骨折端保持较大轴向压缩力，因而对骨的应力遮挡小；与骨的贴合较不紧密，有利于血供恢复，故有利于骨改建。
AbstractThe authors made their own design of sawteeth-arm embracing internal fixator (SEIF)with NiTi shapememorv alloy and used for fractured femoral shaht of dogs in comparison with 316L stainless steel plate-screw system.A transverse osteotomy on both sides offemoral diaphyses was performed in 15 adult dogs.One side was plated with bone plate and the other withSEIF. Five animals in each group were killed at 4,8,12weeks after operation and observed undet roentgenrays examination,light microscopy and transmissionelectron microscopy. The results showed that the frac-ture healing and the course of callus remoddling weresimilar in these two groups,but the cortical bone re-modelling underneath the fixater near osteotomizedarea was significantly different.Eight-week post-im-plantation,osteocytes entered into degenerative phasewere observed in cortical bone underneath SEIF,and12-week after operation,the numbers of degenerativeosteocytes increasedremarkably.While in the case ofbone plate,4-week post-implantation, osteocytes en-tered into degenerative phase,and 8-week afterwardsautolysis occurred in most of the degenerative osteo-cyles. In other words,the changes of osteocytes phasein bone plate side appeared earlier and more vigorousthan that in the SEIF side,The authors are of the opinion that the elastic modulus of NiTi shape memoryalloy is lower, the stress-shielding effect in the boneunderneath SEIF is less,the axial compression stressof fracture line is kept larger and the contact of SEIFwith the bone is not so close that is beneficial to the re-covery of blood supply and bone remodelling.
出处
《中华外科杂志》
CAS
CSCD
北大核心
1995年第8期481-484,共4页
Chinese Journal of Surgery
基金
上海市科委资助课题
