Biomechanical Comparison And Research Of Posterolateral Tibial Plateau Fracture Between The New Plate And Other Three Tratiditional Internal Fixation

Objective: This resarch is to compare the biomechanical performances of the new plate we designed for the treatment of posterolateral tibial plateau fractures with other three traditional internal fixation.Methods: The fragement is cut from the posterolateral tibial plateau with a goose saw and randomly assigned into 4 groups.Group A is fixed with two6.5mm lag screws,group B with the new plate,group C with inverted type L plate,group D with posterolateral buttress plate.Vertical displacements of the posterolateral fragments are measured under axial loads of 500 N、1000N and1500 N in biomechanical experiment.Results: Under the loads of 500 N,group A has the largest displacement of 1.055±0.023 mm.The displacement of group D is minimum which is0.356±0.089 mm.Displacement of the other two groups are 0.543±0.049 mm and 0.379±0.024 mm.When the axial load of 1000 N,group A has the largest displacement of 1.525±0.03 mm.The displacement of group D is minimum which is 0.651±0.062 mm.Displacement of the other two groups are 0.901±0.064 mm and 0.744±0.04 mm.Under the loads of 1500 N,group A has the largest displacement of 1.796±0.04 mm.The displacement of group D is minimum which is 0.903±0.077 mm.Displacement of the other two groups are1.269± 0.073 mm and 1.321±0.05 mm.Except groups C and D under 500 N,groups B and C under 1500 N,the differences between the 4 groups are statistically significant(P<0.05).Conclusion: These four implants can all provide rigid fixation for the block.We can see that the posterior straight fixation is most reliable.The results also show the lag screw has the worst reliability.The new plate and inverted type L plate have the similar biomechanical performance under theaxial load,which provided reliable basis for clinical application of the new plate.