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.