Effect Of Platelet-rich Plasma Combined With Autologous Enriched Red Bone Marrow On The Healing Of Bone Defects

Background and ObjectivesHow to promote the healing of bone defects is an important issue in bone research. Platelet-rich plasma (PRP) is platelet condensate from autologous whole blood. The concentration of platelet in PRP is at least 4 times more than in whole blood. PRP contains high concentration of several kinds of growth factors such as: platelet-derived growth factor (PDGF), transforming growth factor-β1,β2 (TGF-β1,β2), insulin-like growth factor (IGF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), epithelial cell growth factor (ECGF), etc. Researchers have found that platelet-rich plasma has quite clear capability to accelerate soft tissue repair and bone healing. Red bone marrow (RBM) contains many kinds of growth factors, bone morphogenetic protein (BMP), bone marrow stromal cells (BMSCs), endosteal cells, induced osteoprogenitor cell (IOPC) and Determined Osteoprogenitor Cell (DOPC), so it can be an excellent transplant tissue for bone healing. In this experiment, we make rabbit radial bone defect models and observe the influence of PRP and autologous concentrated RBM on bone defect healing to provide a new method for clinical therapy of bone defect. n=18) randomly, then established rabbit bilateral radial bone defect model. PRP was prepared by improved Curasan method. The preparation of autologous concentrated RBM:Under sterile conditions we stabbed rabbit ilium with 16G bone needle, extracted lml red bone marrow by injector which had been prewetted with heparin, then we centrifuged the RBM which was put in centrifuge tubes 10min at 1000r/min. At last we reserved about 0.2ml the under concentrated red bone marrow. Fibrin glue was dissolved by aprotinin solution (80mg/ml) and mixed with autologous PRP and/ or RBM. When the bone defect models had been estabilished, we added catalyst (mixture of 1ml 10% CaCl2 and 1000U thrombin) into the FG/PRP/RBM mixture, and it would be gelatinous after about 20 seconds. We put PRP+RBM+FG into the bone defect of group A animals, PRP+FG into the group B animals, RBM+FG into the group C animals, and put noting into the group D animals which was taken as a control group. After 4,8,12 weeks, we checked the bilateral radial bone defects by gross observation, X-ray examination, histological observation, and use Lane-Sandhu's X-ray grading standard to evaluate the bone defects healing.ResultsAt 4 weeks after operation:We saw much fibrous osteotylus in the bone defect areas of group A animals, more than in the group B and group C. The bone defect areas of group D animals were filled with fibrous tissue. X-ray examination showed that the bone defect areas of group A had patchy radiopaque shadow. The bone defect areas of the B, C groups had continuous floc radiopaque shadow. The group D animals bone defect areas were translucent, could be found a little floc radiopaque shadow at the broken ends of fracture bone. The imaging scores of group A were better than group B, C, D (P<0.05).At 8 weeks after operation:We saw continuous osteotylus which was expansive growing in the bone defect areas of group A animals, and the fracture lines disappeared. The group B, C bone defect areas were filled with hard osteotylus. The group D bone defect areas were clear. X-ray examination showed that the broken ends of fracture bone in group A were fuzzy; bone defect areas were expansive continuous high density radiopaque shadow. The bone defect areas of group B, C were continuous high density radiopaque shadow; two broken ends of fracture bone were fuzzy. The group D bone defect areas were clear. The imaging scores in the group A were better than that in the group B, C, D (P<0.05).At 12 weeks after operation:We saw the bone defect areas of group A had been shaped well, similar to normal bone. The group B, C bone defect areas were filled with hard osteotylus, their diameter was larger than normal radius. The group D bone defect areas were filled with fibrous tissue; the two broken ends of fracture bone were hardened. X-ray examination showed that the bone defect areas of group A disappeared, radius cortical bone was continuous and marrow cavity was link up. The group B bone defect areas had expansive continuous high density radiopaque shadow, marrow cavity had partial recanalization. The group C bone defect area had uniform high density radiopaque shadow; radius cortical bone on both sides was continuous and marrow cavity had partial recanalization. The group D bone defect was clear; the two broken ends of fracture bone were hardened. The imaging scores in the group A were better than that in the group B, C, D (P<0.05).ConclusionWe concluded that PRP combined with RBM using FG as the carrier could significantly promote bone defect healing.