Biomechanical Analysis of Orthopedic Screw Under Bone Remodeling

In order to evaluate the biomechanical stability of titanium alloy screw with different structural parameters under bone remodeling, some three-dimensional finite element models were established and the bone remodeling process after implanting the screw was simulated. Three-dimensional finite element models consist of bone and screw with different lengths and diameters. Bone remodeling process was simulated by user-defined subroutine. It is found that the stress on the bone is concentrated on the groove and root of the internal thread. The screw stress is mainly on the beginning of the thread, and the whole stress decreases along the long axis of the screw. The stress distribution trend of bone and screw did not change significantly during the bone remodeling. The maximum equivalent stress value was different, the maximum equivalent stress on the screw and cancellous bone increased while the maximum equivalent stress value on the cortical bone decreased.