摘要
目的评价低强度脉冲超声对实验性骨质疏松性骨折愈合骨痂力学性能的影响。方法 4．5月龄的雌性 SD大鼠42只,去势后10周证实发生骨质疏松,建立双侧股骨中段骨折模型,选用其中符合标准的26只于造模后第2天起采用自制低强度脉冲超声仪随机对一侧后肢骨折部位进行连续治疗,每天20 min,超声波主频率为1．5 MHz,空间平均时间平均强度为50 mW／cm2,脉冲宽度200μs,周期1 kHz;另一侧做对照。分别于治疗4、6、8、12周后处死大鼠,取双侧股骨行三点弯曲试验比较两侧骨痂的力学性能。结果治疗4、6、8、12周后,治疗侧骨痂的最大载荷分别高于对照侧58．75％,76．53％,37．04％,22．14％;最大应力分别高于对照侧29．21％,66．43％,29．08％, 16．90％;弹性模量分别高于对照侧34．01％,61．04％,46．15％,31．77％。除了4周时的最大应力、4周和6周时的弹性模量差异无显著性意义,其余测量值差异均有显著性意义(P<0．05),其中6周时的最大载荷和8周时的最大应力差异有非常显著性差异(P<0．01)。结论低强度脉冲超声治疗能够明显改善实验性骨质疏松性骨折不同愈合阶段骨痂的力学特性,有效提高骨折愈合的质量,从而为临床治疗提供一种新的思路和方法。
Objective To evaluate the biomechanical properties of the callus during osteoporotic fracture healing with the treatment of low-intensity pulsed ultrasound （LIPUS） in rats. Methods Forty-two female SD rats of 4.5-month-old were involved in the study ,36 of which underwent bilateral ovariectomy. Ten weeks later when the osteoporosis was confirmed, the 36 rats had their bilateral femoral shaft closely fractured. After serious selection only 26 rats finally entered the experiment. On the day after fracture, a hind limb was chosen randomly to receive LIPUS as treatment withthe other limb as control. The LIPUS was done 20 minutes daily with a 200μsec burst of 1.5MHz sine waves repeated at 1kHz and an average intensity of 50mW/cm^2. The rats were sacrificed on 4, 6, 8, 12 weeks after treatment, respectively, and their bilateral femurs were taken for biomechanical analysis with three point bending test. Results When compared with the control side on 4, 6, 8, 12 weeks after LIPUS treatment, respectively, the peak load of the callus in treated side was higher about 58.75%, 76.53%, 37.04%, 22.14%, the peak stress was higher about 29.21%, 66.43%, 29.08%, 16.90%, and the elastic modulus was higher about 34.01%, 61.04%, 46.15%, 31.77%. Except for the peak stress in 4 weeks and the elastic modulus in both 4 and 6 weeks, all the differences were significant （P〈0.05）, especially for the peak load in 6 weeks and the peak stress in 8 weeks （P〈0.01）, Conclusions LIPUS can improve the biomechanical properties of the callus during the osteoporotic fracture healing in rats, thus providing a new way to treat osteoporotic fractures clinically.
出处
《医用生物力学》
EI
CAS
CSCD
2005年第4期235-238,共4页
Journal of Medical Biomechanics
关键词
低强度脉冲超声
骨质疏松
骨折愈合
生物力学
动物实验
Low-intensity pulsed ultrasound
Osteoporosis
Fracture healing
Biomechanical property
作者简介
王磊（1973-），男，博士，研究方向：创伤骨科和关节外科
通讯作者：张先龙，Tel：（021）64369181；E-mail：zxl1964@sina．com
