Experimental study of vascularized bone grafts: XXXX of the grafted bone.

@entity1184 @entity174 @entity35
The mechanism underlying @entity1184 of experimentally vascularized bone grafts was studied in 15-week-old @entity35 . The segmental ulna was grafted to the tibial defect with an external fixator. In experiment 1, 24 @entity35 were classified into four groups to evaluate conventional (non-vascularized), cuff (periosteum-encased, non-vascularized), and vascularized bone grafts, and vascularized segmental grafts with @entity174 . In experiment 2, 12 @entity35 were classified into two groups according to the presence of mechanical loading. This involved vascularized bone grafts with external fixators, and vascularized bone grafts with external fixators removed after bone union. The bone dynamics of the grafts were investigated by several methods, including roentgenographic analysis, histologic studies, and fluorochrome labeling. In experiment 1, a slight bone formation was recognized in the conventional bone graft, while irregular bone formation with creeping substitution was observed in the cuff graft. The vascularized bone graft showed significant @entity1184 ; @entity1184 of the vascularized bone with @entity174 was greater than that without @entity174 . In experiment 2, markedly circumferential bone formation was observed after removal of the external fixator, while slight new bone formation was observed during the late postoperative period in bone with an external fixator. These results suggest that @entity1184 can be promoted by artificial @entity174 of the grafted bone, and that mechanical loading is an important factor for remodeling of grafted bone.
