The Repairing Of Bone Defect With Autografting Of Periosteal Pieces Combined With Cortical Bone

Objective: Bone defects occur often in orthopedic surgery and the treatment is difficult. Now the procedures of bone autografting are used widely in the treatment to bone defect. However, bone autografting are associated with some disadvantages, such as low and powerless osteogenic activity, the areas and sizes of donor site are limited. Research has shown that the osteogenic efficacy of the periosteum is excellent, the strip technique is easy and has less morbidity of the donor site. Free periosteal autografting can do the same clinical effect as bone trantsplanting.After being transplanted into bone defects, the periosteal pieces resolved and turned into "cartilage masses", then became precursore cartilages and bones, the osteogenic process can be defined "multi-centre ossification".The phenomenon has been observed that the osteogenic efficacy were enhanced greatly with autografting of periosteal pieces combined with cortical bone pieces in muscles, the new bones produced by periosteum were abundant and trantsplanted bone were absorbed faster. The cause was that "osteoinduction activity" were promoted by osteoinductive factors contained in periosteum and bones .We will prove "osteoinductionactivity" could be found also with autografting of periosteal pieces combined with cortical bone pieces in bone defects. Therefore, the osteogenic efficacy could be enhanced and repairing speed improved.Methods:45 rabbits were used in this study. They were operated into standard bone defect experimental modals by resected 1.2cm radius bone and divided into 3 groups of 15 animals each.Group A were trantsplanted into periosteal pieces only; Group B were trantsplanted into cortical bone pieces only; Group C were trantsplanted into periosteal pieces combined with cortical bone pieces. At 2 4 6 8 and 12 weeks after operation each group were sacrificed 3 animals. Results were revealed in histology radiography gross observation bone gla protein and bone density.The osteogenic ability and bone repairing speed of three autografting methods were measured in statistics treatments. Results: (l)X-rays and gross observation indicated that bone defects could all be repaired perfectly at 12 week. The callus amount of group C were larger than group B and C before 12 weeks. At 6 week obvious marrow cavity began to appear in bone defect of group C instead of at 8 week in group A and B. (2) The repairing speed of group C was faster than group A and B. At 2 and 4 weeks bone gla protein of group C was significant higher than group A and B(P <0.05). At 2 4 6 and 8 weeks bone density of group C was significant higher than group B and C(P <0.05). At 2 4 6and 8 weeks histology scores of group C was significant higher than group B and C(P <0.05). (3)The repairing speed between group A and B were almost the same in all time.Bone gla protein(at 4. 6^ 8 and 12 weeks) -. bone density(at 8 and 12 weeks)and histology scores(at 2 4 8 and 12 weeks)showed no significant variance(P>0.05). (4)The osteogenic mechanisms of 3 groups were different: Periosteal pieces autogrfting showed "multi-centre ossification". Cortical bone pieces autogrfting showed "creeping substitution". The osteogenic mechanism of group C were not only "multi-centre ossification" added to "creeping substitution", but also included additional direct osteogenesis of periosteum and "osteoinduction".Conclusion: Both periosteal pieces and cortical bone pieces autogrfting could repair bone defects perfectly.When they were mixted together and transplanted into bone defects the repairing speed became faster. The osteogenic mechanism of combinative transplanting showed "osteoinduction", the osteogenic efficacy were enhanced. The method is effective clinically.