Biomechanical Analysis Of A Novel Dynamic Fixed-angle Plate System For Treatment Of Vertical Shear Pauwels Type Ⅲ Femoral Neck Fracture

Objective:The aim of this study was to compare the biomechanical properties of a novel dynamic fixed-angle plate system(DFPS),and traditional dynamic hip screw(DHS)on a Pauwels type Ⅲfemoral neck fracture model.Methods:A Pauwels type Ⅲ femoral neck fracture(Pauwels angel 70 degree)was created on 9 pairs of cadaveric femurs.These specimens were divided into two groups(left side of the specimens was regarded as reference for grouping,the right side was divided into another group automatically).The fracture was fixed with the novel DFPS in the first group and traditional DHS in the second group.Each specimen was tested under incremental loading,cyclical loading,and loading to failure.Axial stiffness,average cyclic displacement and failure strength were measured and the difference value between the pairs was calculated.Result:The differences in axial stiffness and average cyclic displacement between the two groups were not statistically significant(the difference value of axial stiffness:△K=4.788±7.276N/mm,P≥0.05;the difference value of average cyclic displacement:△S=-0.029±0.058mm,P>0.05).The difference in failure strength between the two groups was statistically significant(the difference value of failure strength:△F =98.33±91.37N,P<0.05).Conclusion:Compared with the traditional DHS,the novel DFPS has stronger biomechanical properties and appears to be a more suitable fixation method for Pauwels type III femoral neck fractures.