Increased Distraction Rate Decreases Expression of Angiogenic and Osteogenicgrowth Factors in Distraction Osteogenesis

Introduction The rate of lengthening has a profound impact on bone formation during distraction osteogenesis. At optimal rates of distraction, palisades of well-vascularized woven bone fill the distraction gap. However, rapid distraction leads to the formation of granulation tissue, fibrocartilage, and cysts, resulting in nonunion. Previous research has demonstrated that rapid rates of distraction decrease the expression of cytokines necessary for angiogenesis and osteogenesis. 2 Some suggest this is due to damage of the periosteum, while others believe it may be related to rapid lengthening relative to the age and size of the patient. In this study, we explored whether a rapid rate of distraction leads to a decrease in the angiogenic and osteogenic growth factors; basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF), and vascular marker, platelet endothelial cellular adhesion marker (PECAM1/CD 31) in a rat limb lengthening model.