EVALUATION OF MECHANICAL PROPERTY OF FRACTURE HEALING USING NON-DESTRUCTIVE TESTING

骨的声学各向异性是使用扫描声学显微镜进行的。术后 12 周，从四只小猎犬身上采集了骨折和健全的胫骨。观察了三种测量模式：C模式成像、XZ模式成像和超声速度测量。通过旋转连接到超声波振荡器的狭缝透镜，在0度和90度方向上测量纵向弹性波的超声波速度。各向异性，即与皮质骨长轴平行和垂直的方向上超声速度的差异，对正常胫骨皮质骨中的骨和骨折胫骨的愈合部位进行了研究。骨管中央管附近内侧区域的速度在横截面和纵向上均始终低于外侧区域。两个区域之间的速度差为200至300m/秒。横截面骨不存在声学各向异性。同时，在纵向切片的骨中，平行于中央管长轴的方向上的速度始终高于垂直于轴的方向上的速度。两个方向之间的速度差为800至900m/秒。在骨折胫骨的愈合部位，骨痂区域显示出很少的各向异性，尽管原始皮质区域保持其各向异性。

Acoustic anisotropy of bone was using the scanning acoustic microscope. Both fractured and sound tibias were harvested from four beagle dogs 12 weeks postoperatively. Three kinds of measurement mode were observed : C-mode imaging, XZ-mode imaging and measurement of ultrasound velocity. Ultrasound velocity of longitudinal elastic wave was measured in the directions of 0 and 90 degrees by rotating a slit lens attached to an ultrasound oscillator. Anisotropy, the difference of ultrasound velocity both in the parallel and rectangular directions to the long axis of the cortical bone, was studied on the osteons in the cortical bones of normal tibias and on the healing site of the fractured tibias. The velocity in the inner area near the central canal of the osteon was constantly lower than that in the outer area both in the cross section and the longitudinal one. The difference of the velocity between the two areas ranged from 200 to 300m/sec. There was no acoustic anisotropy in cross-sectional osteons. Meanwhile, in the osteons longitudinally sectioned, the velocity was constantly higher in the direction parallel to the long axis of the central canal than in the direction rectangular to the axis. The difference of the velocity between the two directions ranged from 800 to 900m/sec. In the healing site of the fractured tibias the callus area showed little anisotropy, although the original cortical area maintained its anisotropy.