Effect Of Injecting Platelet-rich Plasma At Different Periods On Distraction Osteogenesis

Objective: To find out the best injecting time and shorten the distraction osteogenesis process by evaluating the effect of injecting platelet-rich plasma(PRP) at different period on distraction osteogenesis.Methods: Thirty-six white rabbits were randomly divided into four groups. Groupâ… without injection of PRP, groupâ…¡,â…¢,â…£were injected with 0.5ml PRP at latency, distraction and immobilization period, respectively. Three animals from each group were sacrificed at 2,4,8 weeks at immobilization period. Dual energy X-ray absorption metry (DEXA) was used to measure regeneration bone mineral density (BMD), HE coloration and scanning electron microscope (SEM) was used to observe bone regeneration. SPSS 11.5 statistical package was used for data analysis and P<0.05 was considered significant difference .Results:1. Bone formation rate of groups that were injected platelet-rich plasma(PRP) was better than the group without injection PRP at the same period.2. At 2 and 4 weeks of immobilization period, bone formation rate of groups that was injected PRP at distraction period was superior to the groups that were injected PRP at latency and immobilization period. At 8 weeks, there were no significant differences in injected of PRP groups.3. At 2, 4 ,8 weeks of immobilization period, the regeneration bone mineral density (BMD), HE coloration and the observation of scanning electron microscope (SEM) of groups that were injected PRP at latency and immobilization period had no significant difference.Conclusion:The results indicate that bone formation rate of groups that were injected platelet-rich plasma(PRP) is better than the group without injection PRP. PRP has an accelerative effect on osteogenesis during bone distraction. Injecting PRP at distraction period may shorten the process of distraction osteogenesis observably and the distraction period is the best injecting period.