Compare Biomechanical Experiment In Fixation Of Pauwels Type-Ⅱ Femoral Neck Fracture By Two And Three Screws

Objective:To compare two parallel and del three AO hollow compression screws in fixation of Pauwels type-Ⅱ femoral neck fracture strength By biomechanical experiments, and to offer a reference for more suitable treatment of clinical choice.Methods:12 elected femur specimens were randomly divided into 2 groups, with 50°bone cutting simulation Pauwels Ⅱ femoral neck fracture, respectively using two parallel configuration and inverted triangle parallel configurations hollow compression screw nails fixed fractures, in vitro human body on one foot weight, use the Shimadzu AGS-X10KN electronic universal material mechanics testing machine for the biomechanical properties of the system test specimen.Vertical axial and torsional loads fracture given, observe and compare the two experimental groups at 500N(simulated upper body weight) compression performance under load, the displacement of measuring femoral head sink and section open angle changes, torsion displacement and torsion angle, under the yield load of axial stiffness, etc.The results for statistical analysis.Results:When Pauwels angle of 50°, two parallel configurations screw group and inverted triangle parallel configurations screw in internal fixation for each index of femoral neck fractures, there were no significant differences.Bboth of the two groups can provide the firm on the biomechanical stability.Conclusions:Use two or three AO compression screw internal fixation treatment of Pauwels 50°ngle (namely Pauwels type-Ⅰ,Ⅱ) of femoral neck fracture effect similar to that of biomechanical properties of the two both can meet the requirements of patients with postoperative functional exercise, but the results do not support AO compression screw internal fixation of postoperative early weight-bearing walking.This still needs large sample clinical follow-up data. Two screws can meet the needs of the stable fixation, and reduce the impact on the blood supply of femoral head, and easy operation, less trauma and operation time, to meet the condition of patients is worthy of popularization and application.