Ohyama M, Miyasaka Y, Sakurai M, Yokobori A T, Sasaki S
Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
Biomed Mater Eng. 1994;4(4):273-81.
Experimental callotasis was made in rabbit femurs. In order to compare mechanical behaviors and morphological structure of callus in callotasis, mechanical tests and histological examination were performed. Twenty Japanese white male rabbits were used. The right femurs were osteotomized at the level of the midshaft with a rotary cutter and fixed with a mini-model external fixator. After a 5-day waiting period, bone lengthening was started at the rate of 0.25 mm two times a day. Animals were divided into four groups. Group 1 and Group 2 were continual distraction group, Group 3 and Group 4 discontinued distraction group. The viscoelastic property was demonstrated in continual distraction group irrespective of distraction period, we thought the central undifferentiated connective tissue in callus was mainly responsible for the mechanical behavior. On the other hand, in discontinued distraction group, viscoelastic property shifted to elastic property corresponding to the rest period, we thought this change of mechanical behavior was histologically owing to the replacement of undifferentiated connective tissue by cartilage and the partial union of bone in callus.
在兔股骨上进行实验性骨痂延长术。为了比较骨痂延长术中骨痂的力学行为和形态结构，进行了力学测试和组织学检查。使用了20只日本雄性白兔。用旋转锯在右股骨中轴水平截断，并用微型外固定器固定。经过5天的等待期后，开始以每天0.25毫米的速度分两次进行骨延长。动物被分为四组。第1组和第2组为持续牵引组，第3组和第4组为停止牵引组。持续牵引组无论牵引期如何均表现出粘弹性，我们认为骨痂中的中央未分化结缔组织是力学行为的主要原因。另一方面，在停止牵引组中，粘弹性随着休息期转变为弹性，我们认为这种力学行为的变化在组织学上是由于未分化结缔组织被软骨替代以及骨痂中骨的部分愈合。
