Long-term mechanical stability of the impacted morselized graft-cement interface in total joint replacement: An experimental study in dogs

This experimental study compared the long-term (12 months) mechanical stabi lity of the morselized graft-cement interface with the conventional bone-ce ment interface in both femoral bones of 10 adult dogs. For mechanical testi ng, three-point bending and push-out loading tests of composite bone-cement beams were used, while the incorporation of the graft was assessed by seri al radiographs. Although the parameters fracture load and interface failure load showed inferior values in the specimens with a morselized graft-cemen t interface compared to those in specimens with a conventional bone-cement interface, no statistically significant differences were found between grou ps. Radiographic reconstitution of the lateral femoral cortex was observed in all animals at 3 months while signs of advanced remodeling were apparent at 6 months. These results indicate the long-term mechanical stability of the impacted morselized graft-cement interface is comparable to that of the conventional bone-cement interface created in primary total hip replacemen ts provided the grafted area is protected from early heavy loading.