低强度脉冲超声促进骨折愈合的生物力学实验研究

目的:探讨低强度脉冲超声对骨折愈合的促进作用.方法:以20只新西兰兔为对象,取双侧桡骨建立分离骨折模型,以左侧桡骨为实验组,进行低强度(30 mW/cm2)脉冲超声治疗(20 min/次,1次/d),右侧为对照(假刺激).分别于第2、3、4、5周末处死动物,取双侧桡骨进行三点弯曲实验及扭转力学实验,观察骨折部位的强刚度特性及其愈合时间.结果:(1)超声治疗组骨折部位抗弯强刚度及抗扭强刚度均明显高于对照组(P＜0.05);(2)随着超声治疗时间的增加,骨折部位抗弯强刚度及抗扭强刚度等逐渐加强(P＜0.05).结论:低强度脉冲超声作为一种机械刺激,可使骨折部位力学特性得到明显改善,并能促进骨折愈合.

Biomechanical study on low-intensity pulsed ultrasound in promoting fracture healing

Objective:To study the promoting effects of low-intensity pulsed ultrasound(LIPUS)on fracture healing.Methods:The animal models of bilateral radial distraction fracture were made in20New Zealand rabbits.Left radius was stimulated by LIPUS(30mW/cm 2 )for20min once a day and right radius was treated with fake stimulation.Bilateral radii were taken out on the2nd,3rd,4th and5th week after operation.The three-point bending stress and torsional mechanical tests were carried out and biomechanical characteristics and healing time were observed.Results:(1)The abilities of anti-bending and anti-torque of left radius was better than those of right one(P<0.05).(2)The biomechanical characteristics of radial callus were continuously improved by LIPUS in accord with accumulation of LIPUS treatment(P<0.05).Conclusion: LIPUS,as a mechanical stimulation,can improve the biomechanical characteristics of callus and promote fracture healing.[