股骨近端异体皮质骨板组织学及生物力学的实验研究

目的 探讨深低温冷冻异体皮质骨板在兔体内的组织学及生物力学性质变化,为临床应用异体皮质骨板提供理论依据。方法将深低温冷冻异体皮质骨板植入兔股骨干外侧,于植入后2、4、8、16、24周取材,对其在体内的生物学替代过程从影像学、组织学、生物力学方面进行分析。结果x线可见异体皮质骨板在植入体内8周与宿主骨愈合。组织学可见异体骨板内表面早期即有毛细血管长入,有破骨细胞骨吸收,之后有新骨生成,术后8周异体骨5％被新生骨替代,术后16周异体骨12％被新生骨替代,术后24周异体骨21％被新生骨替代,外表面骨吸收及新骨生成不明显。在植入4—8周可见骨痂包绕异体骨,与宿主骨已开始有骨愈合,植入16周后可见宿主骨与异体骨间有骨生成。异体骨强度在植入早期下降较快,植入16周时,异体骨强度为原强度38％,之后强度下降速度较慢,到24周时为原强度36％。结论异体皮质骨板主要靠宿主骨痂包绕其边缘而愈合,异体骨板与宿主骨相接触内侧被替代且有新骨生成。

The experimental study of histomorphology and biomechanical of cortical strut allograft in proximal femoral

Objective To explore the deep-frozen allograft strut in the rabbits for the sake of finding some evidence to support the clinical practice of cortical strut allograft. Methods Fifty deep-frozen allograft struts were implanted on the lateral side of the femor in 50 male New Zealand white rabbits.These rabbits were randomly divided into 5groups.The spicemen were retrived at 2,4,8,16,24 weeks after surgeries. In each group histomorphology and biomechanic properties were studied. Results From the X ray photographies the edge of the strut would turn blunt at the 4th week,union could be found at the 8th week,the inner side of the strut could be absorbed at the 24th week.In the early stage when the strut was implanted in the rabbit,the capillary would be found to grow into the cortical strut from the interior side of it. Then the capillaries were found to converge at the 16th week.This phenomenon is correspondent with the resorbtion of the dead bone and formation of the new bone. There are few neoformated capillaries on the lateral side of the strut. From the decalcificated section,allograft struts were found to unit to the host at 4 to 8 th week. Osteoclast and the new bone formation could be seen at the 8 th week,and 3% of the total area of what had been the allograft was replaced by the new bone at that time,12% was replaced at the 16 th week,21% at the 24 th week. There are few resorbtion or neoformated bone at the lateral side of the strut. The biomechanical property indicated that the strength of the strut decreased at the early time,and only 38% of its original strength remained at 16 weeks. Conclusions The cortical allograft strut can unit to the host by the callus. The capillaries invading into the allograft from the interior side,new bone is formed from the interior side .The biomechanical strength of the strut decreased at early stage.