Experimental Study On The Influence Of Storage Time In Vitro On Bone Autograft Healing

OBJECTIVE: To discover the influence within four hours of different storage time in vitro on the activity of osteoblast and osteogenic capability in bone autograft .METHOD: Kept the ilium blocks in 0.9% saline at room temperature for 0﹑1﹑2﹑3 or 4 hours before osteoblastic cell culture or replacement to extra-skeletal muscle gaps in the same rabbit. The grafts transplanted to muscle gaps were divided into two types: irrigating bone marrow with saline and non-irrigating bone marrow . The amount of osteoblast in cell culture was taken counting at each group in each day . The histological specimens of the autograft in extra-skeletal muscle gaps were taken at 3rd days and 1﹑2﹑4﹑6 weeks after operation, and stained by ALP,PASand HE.RESULT: Osteoblasts appeared in each group at three days later after cell culture, then the amount of osteoblast gradually increasing, the volume of cell gradually enlarging , and grown to the circumference in radiative or spiring shape. The statistical results of the numbers of osteoblast showed that there was no notable discrepancy between each culture group in each day. There could observe survival osteocytes and osteoblasts in all ectopic graft groups three days after operation, but no new bone formation. New osteoid tissues formed one week after operation .New osteoid tissues increased at two weeks and gradually transformed into woven bone and lamellar bone tissues. The results of morphometry analysis showed there was no remarkable difference among all ectopic graft groups. CONCLUSION: Storage of the bone blocks in 0.9% saline for four hours before cell culture or implant would not influence the activity of osteoblast, and had no remarkable influence on the capacity of bone formation in bone autograft. Irrigating bone marrow with saline would not influence the survival of autograft and the capacity of new bone formation. Therefore, it was a reasonable method to keep bone blocks in saline before implant. There was no remarkable influence on bone healing to replace grafts immediately or store in saline within four hours before replacement.