Vascular Endothelial Growth Pattern of Endochondral Bone Graft in the Presence of Demineralized Intramembranous Bone Matrix—Quantitative Analysis

Abstract

Objective

To determine the timely ingrowth of new blood vessels of composite endochondral (EC) bone and demineralized bone matrix (DBM) prepared from intramembranous (IM) origin (EC-DBMI_M) and to compare it with EC bone graft alone.

Design

Thirty-two rabbits with 32 critical-size (10 × 5 mm), full-thickness bony defects in rabbit parietal bone were divided into two groups: composite EC-DBM_IM group—mplanted with compositeautogenousEC bone and DBM_IM; EC bone group—mplanted whEC bone alone. Two rabbitsfrom each group were sacrificed 1, 2, 3, 4, 5, 6, 7, and 14 days after grafting. Neovascularization was assessed by immunohistochemical staining with antihuman angiogenesisrelated endothelial cell antibodies (EN 7/44). Quantitative analysis of neovascularization, represented by percentage area of positive immunohistochemical staining, was performed on 320 sections of the experimental groups by a computer-assisted image analyzer.

Results

Positive immunohistochemical staining was first identified on day 2 post grafting for the composite EC-DBMI_M group in comparison with day 4 in the EC bone graft group. The composite EC-DBMI_M bone graft group showed earlier and almost 100% more neovascularization when compared with the EC bone graft group.

Conclusion

DBM_IM enhances healing and integration of EC bone graft by enhancing vascularization as well as increasing the amount of new blood vessels formed. In clinical cases in which EC autogenous bone is used to graft a large defect such as in cleft palate and craniofacial surgery, DBMI_M should allow better integration and healing of the EC bone graft to the host bone.