Objective:To explore the biomechanical stability for treatment of femoral neck fracture with ideal compression screw(I.CO.S.)and to provide theoretical basis for choosing appropriate geometric configurations of two I.CO.S.s in clinical application.Methods:20 cadaveric human femurs were selected and divided randomly into two groups:experiment group and control group

10 in each one which was then divided equally into two sub-groups.The model of subcapital femoral neck fracture was made

then given anatomical reduction and fixed with I.CO.S.(experiment group)and general cannulated compression screw(control group)separately with two different configurations:horizontal one(parallel screws in superior as pect of femoral neck)and vertical one(parallel screws in sagittal plane of femoral neck).The different biomechanical performances were evaluated through experimental stress analysis.Results:In biomechanical stability aspect

I.CO.S.was better than general screw in the horizontal displacement and yield load;the horizontal one was better than the vertical one in respect of the straining

horizontal displacement and yield load.Conclusion:There exists good biomechanical stability for treatment of femoral neck fracture with I.CO.S.

and the horizontal I.CO.S.internal fixation with higher stability can be used for treatment of femoral neck fracture.