In vitro study of axial pullout of pedicle screws

【摘要】：正Various medical screws are widely used in orthopedic joint surgery procedures to support the fusion process of fractures and to stabilize bone transplant.Unfortunately,these fusion implants do not always maintain sufficient long-term stability over time,which often result in failure of the implant and fusion construct.Hence,it is essential to ensure high reliability level of these fusion implants at all times.Many bio-mechanical studies have demonstrated that numerous parameters affect screw pullout resistance using synthetic bone Those parameters include the screw outer and core diameters as well as the thread pitch,pilot hole dimensions,im-