Objective: To investigate the effects of internal fixation with different plates on repairing of rabbit’s femoral diaphyseal defect. Methods: Fifteen New Zealand adult white rabbits were used to produce right femoral diaphyseal defect models and they were randomly divided into three groups with each plated with HA-coated titanium alloy plates

ordinary titanium alloy plates or stainless steel plates. Segments of HA artificial bone were also employed to fill the defects in the two groups fixed with titanium alloy plates. Animals in each group were sacrificed successively in 2

4

8

12 and 16 weeks with 3 each time after plate fixation. Samples were harvested to undergo gross anatomy

histological examination and scanning electron microscopy (SEM). Results: It was found that new bone formation had been quicker with better quality and more quantity in the group with HA-coated titanium alloy plate fixation than in other groups

that HA-coated titanium alloy plate had had commendable biocompatibility with animal tissue and there had been apparent osteoconduction effect. Conclusion: Fixation with HA-coated titanium alloy plate is more stable than other plates and is suitable in repairing bone defect.