Biomechanical Evaluation about Standard Specimen of Intramedullary Expand Self-locking Nail(IES)

A new kind of internal fixation,witch without the orthodox lockpin—the standard spencimen of Expand Self-locking Nail(IES),a biomechanic test were made.Six pairs fresh adult moist cadaveric femur specimens were used to manufacture bone model about 10 cm.Group 1 were fixed using the standard specimen of intramedullary expand self-locking nail and group 2 were fixed by the standard specimen of homemade interlocking nail.All specimens were made biomechanic test and the data was analysed by static SPSS13.0 software.The stiffness of group 1 in resisting rotation and axial displacement and resist bending were smaller than that of the group 2.But there was not static different between two groups.It is conclused that being used in bone model,the internal fixture of intramedullary expand self-locking nail is firm and dependable,with enough power resisting rotation and axial displacement and resist bending of the function,and accorded with the principle of biology fixation.It would be widely used in clinical practice.