中文摘要：

目的探讨低频脉冲超声对载荷万古霉素丙烯酸骨水泥-假体柄界面剪切应力的影响。方法制备1%万古霉素骨水泥-假体柄界面模型，数字表法随机分为对照组、450 mW/cm^2超声组和1 200 mW/cm^2超声组，每组8个样本。对照组37 ℃磷酸盐缓冲液（PBS）中浸泡30 d，超声组37 ℃PBS中超声处理7 d后再浸泡23 d，试件空气中风干24 h后万能力学试验机检测界面剪切应力，场发射扫描电子显微镜和Image-Pro Plus 6.0图像处理软件分析界面孔隙率。结果超声干预1周后，450 mW/cm^2组和1 200 mW/cm^2组界面剪切应力分别较对照组下降9%（P〉0.05）和17%（P〈0.05），两超声组之间无明显差异；450 mW/cm^2和1 200 mW/cm^2超声组界面孔隙率较对照组分别增加44%（P〉0.05）和110%（P〈0.05），1 200 mW/cm^2超声组界面孔隙率较450 mW/cm^2组增加46%（P〈0.05）。超声组界面体液渗透明显增加。结论低频脉冲超声干预1周可显著增加界面孔隙率，提高体液渗透界面，降低界面剪切应力，降低丙烯酸骨水泥-不锈钢假体柄界面初始稳定性。

英文摘要：

Objective To investigate the effects of low- frequency pulsed wave ultrasound on the shear properties of interface of the vancomycin -loaded acrylic bone cement-stem. Methods The interfaces of 1% vancomycin-loaded acrylic bone cement-stem specimences were successfully manufactured and randomly divided into three groups：the control group, 450 mW/cm^2 ultrasound group and 1 200mW/cm^2 ultrasound group, each group consisted of eight samples. Two ultrasound groups were exposed to a local ultrasonic field for 7 d, then immersed in PBS for 23 d, and the control groups were immersed in PBS for 30 d. After curing in air for 24 h, the shear strength of the stem-cement interface was determined by push-out test. The specimens were then photographed using SEM and analysed using Image-Pro Plus 6.0 to determine the porosity at the stem-cement interface. Results The mean shear strength of stem-cement interface additionally decreased by 9% （P 〉 0.05 ） and 17% （ P 〈 0.05 ） in 450 mW/cm^2 ultrasound group and 1 200 mW/cm^2 group respectively comparing with the control group, but no significant difference was found between the two ultrasound groups. The porosity at the stem-cement interface additionally increased by 44% （ P 〉 0. 05 ） and 110% （ P 〈 O. 05 ） in 450 mW/cm2 ultrasound group and 1 200 mW/cm^2 group respectively comparing with the control group, furthermore. The porosity in 1 200 mW/cm^2 ultrasound group increased by 46% （P 〈0. 05） comparing with the 450 mW/cm^2 group. There are much more fluid penetration along the stem-cement interface in ultrasound group. Conclusion Low- frequency pulsed wave ultrasound signifiantly enhanced porosity and fluid penetration interface, and reduced the interface shear strength and initial stability.