Histology Changes Of Vascularization And Osteogenesis In The Non-Cell Based Tissue Engineered Bone Promoted By The Pedicle Fascia Flap

To demonstrate the pedicle fascial flap has a fine effect of vascularization and can benefit osteogenesis and to provide a basic theory and feasible method for the large segment bone defect repair in the clinical by histology observation about the vascularization of the non-cell based tissue engineered bone promoted by the pedicle fascial flap and the effect on osteogenesis in each period of the bone repair.The animal model and the pedicle fascial flap were constructed and the80Newzealand rabbits for the experiment were divided into four groups that Group A, Group B, Group C and Group D randomly, each group with20rabbits. The control groups were Group A with the non-cell based tissue engineered bone simply, Group B with the non-cell based tissue engineered bone packed by the fascial flap without pedicle and Group C with VEGF the non-cell based tissue engineered bone packed by the fascial flap. The experimental group was Group D with the non-cell based tissue engineered bone packed by pedicle fascial flap. The morphology and histology observation, the bone morphology quantitive analysis and the vessel image quantitive analysis in the junctional and central area were performed on the4th,8th,12th and16th week after the operation.Group D was superior to Group A, Group B and Group C not only in the aspect of the regenerated vascular area but also in the aspect of the new bone trabeculae quality and quantity on each period by histology observation. The vessel constructing between the pedicle fascial flap and the implant was in the form of vertical budding growth on the4th week after the operation in Group D; the volume of the regenerated vessels reached the peak with a large amount of new bone trabeculaes and cartilage cell groups around them and the density of the vessels was in positive relation to the volume of the new bone trabeculaes on the8th week in Group D; both the regenerated vascular area decreased gradually and the new bone trabeculaes and the cartilage cell groups also decreased gradually but the mature bone trabeculaes increased obviously on the12th week in Group D; the membrane like structure growing out of the pedicle fascial flap still existed and the regenerated vascular area reduced further, but the implant was absorbed and degenerated, replaced by the new bone tissue completely, the mature bone structure formed well and the medullary cavity was recanalized on the16th in Group D. The measurement of the regenerated vascular area and the new bone trabeculae area in the junctional and central zone manifested that the effect of vascularization and osteogenesis in Group C and Group D was superior to that in Group A and Group B and the difference had statistical significance(P<0.05), but the difference between Group C and Group D and the difference between Group A and Group B had no statistical significance(P>0.05) on the4th week; the regenerated vascular area and the corresponding new bone trabeculae area of Group D were much more than that of Group A, Group B and Group C and all the difference had statistical significance(P<0.05) on the8th,12th and16th week after the operation.The pedicle fascial flap can promote the vascularization of the non-cell based tissue engineered bone obviously and the enhancement of the vascularization is beneficial to osteogenesis, which can improve the quality and quantity of the bone and shorten the time of osteogenesis. So the vascularization osteogenesis of the non-cell based tissue engineered bone promoted by the pedicle fascial flap is an ideal method to the large segment bone defect repair at present.