骨外固定器轴向加压对骨折愈合影响的实验观察

本试验对青山羊胫骨骨折端分别施加不同的压应力,观察其对骨折愈合的影响。体外测试表明本外固定器具有较低的应力保护作用。X线片发现随着加压量的增大,外骨痂出现渐晚且骨痂量减少,术后6周轻度加压者骨折线模糊,重度加压者外骨痂中仍可见与骨折线平行的透光影。力学测试虽各组间无统计学差异,但轻度加压者骨折愈合强度更接近正常骨。组织学检查各组骨折均为二期愈合,切片中可见内、外骨痂及桥梁骨痂,但随着加压量增大,骨痂成熟度下降。

A study on the effects of axial compressive external fixation on fracture-healing in goats

Transverse fracture was inflicted to the tibia of goats and specially designed external fixator was used for fixation to observe the relationship of different intensity of compres-sive force with fracture-healing.It was found in vitro test that the external fixator possessed less effect of stress protection.X-ray examination revealed that the stronger the compressive force was applied,the later the external callus would appear and the less amount of external callus would form.In the 6th week after fracture,the fracture line became oblierated in cases with mild compression while a transparent line in the external callus could be seen on x-ray films in those cases with heavy compression.Though there was no significant difference of the parameters of torsionmetry among different groups,the strength of the healed fracture with mild compression was nearer to the strength of a normal bone than that with heavy compression.Histo-logical examination revealed that all the bone unions belonged to secondary bone healing and bone callus became less matured along with the increase of compressive force.