低强度脉冲超声对去势大鼠种植体早期骨整合的影响

Effects of different intensity of low-intensity pulsed ultrasound on early osseointegration of implants in femurs of ovariectomized rats

目的探讨不同强度的低强度脉冲超声对去势大鼠股骨种植早期骨整合的影响。方法 40只经双侧卵巢切除术后12周的雌性SD大鼠,于双侧股骨干骺端植入柱状钛合金种植体,分为两组,每组各20只。术后2天开始对右侧股骨种植体周围分别进行30 mW/cm2和80 mW/cm2强度的低强度脉冲超声照射,作为试验侧,每天1次,每次20分钟,左侧股骨进行空照射,作为自身对照侧。术后第4、8周分批处死动物,每批20只,每组10只,获取双侧股骨标本,进行Micro-CT扫描及三维重建和生物力学性能检测。结果与对照侧相比,试验侧股骨种植体的骨整合相关参数均有所增加。4周时不同照射强度的试验侧之间,骨整合相关参数的增加率差异无统计学意义(P>0.05)。8周时80 mW/cm2的照射强度显示出更好的生物学效应(P<0.05)。结论低强度脉冲超声可加快去势大鼠股骨种植体骨整合的形成,有利于种植体初期稳定性的改善。较高强度的低强度脉冲超声更有利于种植体的长期维护。

Objective To investigate the effect of low-intensity pulsed ultrasound on early osseointegration of implants in fe- murs of ovariectomized（OVX） rats. Methods Forty OVX rats accepted an implant insertion in the bilateral femurs after 12 weeks of bilateral ovarieetomy. The animals were randomly divided into two groups. After two days of implantation, the right femurs of one group started receiving the stimulus of low-intensity pulsed ultrasound once a day and twenty minutes at a time with 30mW/cm2intensity, while another group with 80mW/cm2intensity. After 4 and 8 weeks of implantation, ten rats of each group were sacrificed and their femurs were retrieved for Miero-CT analysis and biomechanieal test. Results The fight side revealed improved osseointegration compared to the left side. The increase rate was no difference between the two groups at four weeks, but the 80mW/cm2 intensity group is better at eight weeks. Conclusion These results demonstrate that low-intensity pulsed ultrasound could enhance the early osseointegration of implants in OVX rat＇s femurs, and suggest the feasibility of using low-intensity pulsed ultrasound to improve early stabilization and long- term results of implant in poor bones.