不同力学环境影响同种异体皮质骨板移植生物学转归的实验研究

An Experimental Study of the Effect of Biomechanical Environment on the Incorporation of Cortical Bone Plates Allografts

16只山羊造成右侧股骨骨折,双侧股骨分别进行同种异体皮质骨板移植,右侧移植骨板承受生理应力,左侧不承受应力.分别在术后3、6、12、24周处死动物取材,通过组织学检查以及血管墨汁灌注率、孔隙率、四环素荧光标记和新骨形成积分光密度值图像分析,对移植骨板修复进行检测.结果显示,未承受应力侧术后3周,承受应力侧术后6周移植骨板出现再血管化.术后3～6周,不承受应力侧移植骨板血管面积比率、孔隙率、四环素荧光标记和新骨形成积分光密度值大于承受应力侧(P＜0.05);而6周以后则承受应力侧大于未承受应力侧(P＜0.05).结果表明,同种异体皮质骨板移植术后早期承受应力延缓了移植骨板再血管化;患肢术后制动6周,待骨折端骨痂连接、移植骨板再血管化以及部分骨板与宿主骨发生骨性连接后,患肢承受生理载荷有利于移植骨板新骨形成和内部改建.

Sixteen goats with fractures of right femur received cortical bone plates allografts on both the sides of femurs. The right allograft strut endured the stimulation of physiological stress, and the left allograft strut did not. Groups of goats were sacrificed and specimens were procured at 3, 6, 12, and 24 week after surgery for histology observation and image analysis of the vessels after Chinese ink perfusion, the rate of bone porosity, the integrated optical density（IOD） of tetracycline fluorescence labeling and new bone formation were investigated in order to evaluate the incorporation of the allograft strut. The allograft strut revascularized at 6 weeks after surgery in the fracture group, but at 3 weeks in the control group. The rate of area of vessels after Chinese ink perfusion, the rate of bone porosity,the integrated optical density（IOD） of tetracycline fluorescence labeling and new bone formation in the fracture group were worse than control from 3 weeks to 6 weeks, but the observed and measured values were better in the fracture group than in the control group beyond 6 weeks after surgery（P〈0. 05）. The stimulation of stress would be harmful to the allograft strut if the strut endured the stress at an earlier period postoperation. Yet, it would be beneficial to the revascularization, new bone formation, substitution, and internal re-building on the strut provided that the extremity was immobilized for 6 weeks ; and if the cortical graft endured the stimulation of physiological stress from 6 weeks postoperation till cancellous conjunction between the ends of fractures, the revascularization on the allograft strut and the bone conjunction between partially allograft strut and host would be faciliated.