Abstract:Objective To determine the mechanical properties of the interlocking expanding compressive screw(HZS) to treat the femoral neck fracture and present the scientific data for its further clinical uses. Methods The models of femoral neck fracture were made in 8 cases of the fresh cadaveric human femurs. The fractures were reduced anatomically and fixed with the interlocking expanding compressive screw, dynamic compressive screw, twin compressive screw and three cannulated screws individually. Then the specimen were tested on the material machine. Results The models of HZS were strongest of all for against the compression, flexion, shearing and torsional force. The HZS has the good impact effect between the two fracture segments which could accelerate the bone healing. Conclusion The interlocking expanding compressive screw is a new kind of optimal fixator for the femoral neck fracture due to its superior mechanical properties to any other ones.