| Objective To explore the feasibility of using bone cement materials to make internal fixation materials for the treatment of tibia fractures in rabbits,and compare them with conventional titanium bone plate treatment.Method Mechanical test: Bone cement material was made into 8 cuboids with the same shape as the tibial titanium alloy bone plate.According to requirements,it was placed in a universal testing machine for axial compression test and torsion test to obtain its compression strength and elasticity.Modulus and torsional stiffness.Eight fresh rabbit femurs were taken for the above test and corresponding conclusions were reached.Finally,the relevant mechanical parameters of bone cement and rabbit femur were compared with the known mechanical parameters of tibial titanium alloy bone plate.In vivo experiments: 60 New Zealand white rabbits were randomly divided into a control group and an experimental group.The two groups of subjects were made with a wire saw to create a transverse fracture at the distal end of the tibia and fibula at the center of the right tibia at 3mm.The control group used titanium alloy bone plate for fracture internal fixation.In the experimental group,bone cement was molded to form a shape that closely fits the fracture site for internal fixation.The general condition of the experimental subjects was observed and recorded daily after the operation.The two groups of subjects underwent X-ray examinations at 2,4,and 8 weeks after surgery,and the results of each X-ray were evaluated according to the X-ray film epiphyseal evaluation criteria developed by Johnson et al.To observe the healing.After each Xray examination,that is,2,4,and 8 weeks after surgery,2 rats in each group were sacrificed randomly,and the epiphysis and soft tissues at the fracture site were removed for HE staining,and the healing was observed.Results(1)Biomechanical test: The compressive strength of rabbit femur,bone cement material,and tibia titanium alloy bone plate were 23.87 ± 2.48 MPa,71.84 ± 1.64 MPa,and 963 MPa;the elastic modulus was 2.15 ± 0.21 GPa,2.63 ± 0.09 GPa and 113.8 GPa;the shear modulus was 0.85 ± 0.05 GPa,1.06 ± 0.08 GPa and 44 GPa.The difference was statistically significant(P <0.05).(2)X-ray examination results: Comparing the same stage at 2,4,and 8 weeks after surgery.At 8 weeks after surgery,in the X-ray results of the control group and the experimental group,the healing standards reached V grades of 80.77% and 84.61%,respectively.There is no statistical difference.Significance(P> 0.05).(3)Pathological observation results: 2 weeks,4 weeks,and 8 weeks after operation,HE staining results of fracture sites in each group showed that the number of chondrocytes and osteoblasts in the same healing period was similar in both groups,and the stump chondrocytes bone The degree of transformation is close.Conclusions(1)The compressive strength,elastic modulus and shear modulus of bone cement bone plates are higher than those of rabbit femoral cortex and far lower than titanium alloy bone plates;(2)Compared with titanium alloy bone plate treatment,bone cement Internal fixation can be used in the treatment of rabbit tibia fractures,and has a high degree of fit,has no serious impact on surrounding tissues,and has good biocompatibility. |
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