应力遮挡效应与骨折愈合的实验和临床研究

通过动物实验、电测试验及临床观察对应力遮挡效应对骨愈合的影响及其防治原则进行分析。结果表明钢板刚度不是导致骨表面及内部应力重分配和应力遮挡的唯一因素。早期主要与血运破坏和骨内部结构重建有关，与应力减少并不相关，中期与钠板的异物反应有关，中后期如能进行正常的负重功能练习，那么钢板应力遮挡效应及多方面因素引起的骨质疏松对骨折愈合及骨机械性能的影响都是很小的。肢体废用才是导致后期骨理化性质和机械性能降低及再骨折的主要原因。加强肢体负重功能练习及消除异物反应、感染等因素是防治应力遮挡效应及骨关节固定综合征的关键。

Strees shielding and fracture healing

he influence of stress shielding after fracturefixation with plate on fracture healing was studied.The results of animal and biomechanical experimentsas well as the clinical observations demonstrated thatrigidity of the plate was not the only factor causingstress redistribution and stress shielding effects ofbone. Either the internal fixation with different im-plants or external fixation with fixators all mightlead to physical and chemical characteristic changesof bone tissue. In the early stage, the disturbance ofblood supply and the bone structure remodeling maybe the main reasons. Reaction to the implant was an-other cause in the middle stage. If the affected limbcan take weight-bearing normally at late stage, theinfluences of plate on fracture healing mechanicalproperties of bone and the osteoporosis cause bystress shielding effects will become much less. The tis-sue of the affected limb was the most important fac-tor which may cause osteoporosis and refracture.Osteoporosis, bone atrophy and immobilizationsyndrome of bone and joint can be prevented andtreated by taking normal weight-bearing and overcoming infection and implant reaction.