TCP-PMMA骨水泥-骨界面强度变化的研究

目的探讨具有生物活性的三磷酸三钙骨水泥(TCP-PMMA)用于人工关节固定的可能性。方法25只大白兔随机分成5组,在左右侧股骨远端均造成一标准骨缺损模型(直径6mm,长12mm),实验侧置入TCP-PMMA骨水泥,TCP占TCP-PMMA总重量的35%;对照侧为单纯骨水泥PMMA。在术后2、4、8、12、16周,分别进行骨-骨水泥界面强度测定。结果TCP-PMMA骨水泥侧,界面抗剪强度在植入后2周略有下降,但植入后4周至16周逐渐增强,特别是12周至16周,强度明显高于2、4、8周(P<0.05);并且12和16周的界面抗剪强度明显高于纯骨水泥对照侧。对照侧,在观察期2至16周内,界面抗剪强度无明显变化(P>0.05)。结论TCP-PMMA骨水泥-骨界面强度高于单纯骨水泥;在416周内,其强度随时间的延长而逐渐增强。

Experimental study on the shear stress of the interface between the bone and the TCP-PMMA

Objective To find out whether the TCP-PMMA cement can be used for artifical joint fixation . Methodstwenty-five rabbits were randomly divided into five groups, a standard hole whose diameter and length is 6 mm and 12mm respectively was made in the distal femur.one hole was filled with TCP-PMMA (the proportion of TCP in the TCP-PMMAwas 35% in weight),the opposite side was used as control,the hole was filled with pure PMMA cement. The shear stressof interface between the cement and bone were tested at 2,4 ,8,12 and 16 weeks postoperatively. Results The shearpowers were reduced slightly at 2 weeks postoperatively ,and increased gradually during observed period, especially at12 weeks and 16 weeks ,and larger obviously than before and control side. No change was found at control sides duringthe observed period . Conclusion The shear stress of the interface between the bone and TCP-PMMA was larger thanthat of pure PMMA cement.