| Objectives: To observe the morphological changes of osteogenesis in the interface in repairing rabbit radius segmental bone defect with porous tantalum to provide the experimental basis for bone defect repair, arthroplasty and osseous fusion in clinic.Methods: 1 Preparation of materials and experimental groups: The porous tantalum was manufactured to cylinder with diameter 4mm and higher 20 mm. Totally 45 New Zealand white rabbits were randomly divided into 3 groups, 18 in the fascia group, 18 in the tantalum group and 9 in the blank group. 2 Surgery method and X-ray: We make rabbit radius segmental bone defect with 20 mm length along the radius axial. The implant entrapment into defect area and nothing was implanted in the blank group. The X-ray examination was taken at 4,8,16 weeks after the surgery. 3 Sampled and gross observation: The samples were observed by gross and morphological, scanning electron microscopy,hard tissue slices and Micro–CT. 4 Paraffin routine histological observation and capillary count of the porous tantalum bone interface:The growth of new bone was observed at the interface under optical microscope. Observe the regeneration of new bone and the bone defects in the blank control group, count the small blood vessels. 5 Hard tissue slicing: Observe the growth fibrae and bone in porous tantalum-bone interfaces.Six sections were randomly selected at 16 weeks and be measured by IPP 6.0. 6Scanning electron microscopic observation of porous tantalum: The growth of capillary regeneration, bone and fibrous tissue in the porous tantalum-bone interface was observed.7 Micro-CT analysis: The samples were harvested for Micro-CT analysis. And threedimensional reconstruction and bone histomorphometry analysis were also performed in each groups 16 weeks after the surgery.Results: 1 X-ray observation: The combination of porous tantalum with bone became periosteal reaction in different degree. No transparent bands and bone dissolution were found. There was no gap between the porous tantalum—bone interface and the low density of the new bone in the two groups. 2 Gross observation: We saw a few osteoid tissue in the defect area in the fascia group and the tantalum group four weeks after the suegery, and the defect in the blank group was still clear; The defect in the fascia group and the tantalum group was gradually covered by osteoid tissue 8 and 16 weeks after thesurgery, but the tantalum group repaire was slightly less than the fascia group. The defect was still clear and be filled with fibrous tissue in the blank group. 3 Histological examination: The new bone trabecular bone formed at the tantalum bone interface was gradually formed at the tantalum bone interface, and the new bone tissue gradually matured. The bone defect of the control group remained, fibrous membrane wall.At the same time, the number of small vessels showed that the number of small vessels in the fascia tantalum group was significantly higher than that in the tantalum group(P<0.05). 4Hard tissue slicing observation: New bone tissue increased between porous tantalum and host bone in the fascia group and the tantalum group, and new trabecular bone grew into the pores of porous tantalum gradually. The combination of new bone with porous tantalum became more tight.And the defects in the fascia group and the tantalum group were gradually covered by new osteoid. Bone histomorphometry analysis showed the quantity and quality of trabecular bone were superior in the fascia group compared to the tantalum group at16 weeks after the surgery(p<0.05). 5 Scanning electron microscopic observation: The calcium salt deposition, osteoblasts and new bone grew into the pores in both groups gradually increased, and the porous tantalum was covered by extracellular matrix, which was better in the fascia group compared with the tantalum group. 6 MicroCT analysis: The trabecular bone and new bone were more in the fascia group compared with the tantalum group. Bone histomorphometry analysis showed the quantity and quality of trabecular bone were superior in the fascia group compared to the tantalum group 16 weeks after the surgery(p<0.05).Conclusions: 1 Vascularized fascia flap can accelerate the revascularization process of porous tantalum in repairing bone defect. 2 Fascia. Porous tantalum can accelerate the repair of segmental bone defects, the osteogenesis was significantly higher than that of porous tantalum, has a significant effect on the quality and quantity of bone defect repair.3 The porous tantalum and the host bone tissue were in the biological bony binding, and the combination of the tantalum bone interface was high. |
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