Biomechanical factors in the design of new femoral neck screw in children / 中国组织工程研究

ABSTRACT

BACKGROUND:As the epiphyseal plate has an important role in the growth and development of femur, the design of internal fixation should avoid the damage to the epiphyseal plate. Therefore, the positioning of pediatric femoral epiphyseal plate is particularly important. OBJECTIVE:To investigate the biomechanical property of the new femur neck screw internal fixation in treatment of children femoral neck fracture. METHODS:Twelve femurs were col ected from six fresh children cadavers provided by Dissecting Room of University of South China. After exclusion of bone disease with X-ray film, three new children femoral neck screws and three Kirschner wires with the diameter of 2.0 mm were used for fixation. The biomechanical tests were conducted to detect the axial compression and torsion stiffness. RESULTS AND CONCLUSION:In the children femoral neck screw group, the axial compression stiffness and torsion stiffness under the torsional torque of maximum 3 N?m were (190.74±20.88) N/mm and (0.18±0.045) N?m/° respectively;(138.95±15.19) N/mm and (0.120±0.036) N?m/° respectively in the Kirschner wire group;there were significant differences in the axial compression stiffness and torsion stiffness between two groups (P<0.05). The results showed that the compressive strength and torsional capacity of the children femoral neck screw were strong than those of Kirschner wire. The experiment suggested that the femoral neck screw for children is a new type of ideal internal fixation device which consist with the anatomical features of children proximal femur and can meet the requirement of children femoral neck fracture with good biomechanical property.