Performance Analysis of Orthopedic Screw Used for Fixation of Fracture of Bone

In orthopedic surgery, various implants, such as screws, plates, and nails, are used to fix fractured bones. Often the fracture pattern influences the use of such implants, which facilitates the union. The conventional screw used mainly depends on the significant structure of the thread design. However, screws are used independently or with plates for the fixation of fractures of bones. Axial compressive load, bending load, and rotational load (Torsion) are experienced by the bone of the human body. Therefore, the orientation of screws in the bone is exposed to such limitations. Hence, it has been pertinent to analyze the efficacy of the direction of the screw being fixed in bone concerning immobilization of the fracture site for the union. In this study, the effect of axial compressive and rotational loading has been given prime importance since the bone has been minimally exposed to bending load. Further comparative analysis of maximum deformations and stresses for two different orientations of screws subjected to other limitations and torques simultaneously have been performed. A cortical section of the femur bone of a middle-aged man has been modeled, and subsequent finite element method (FEM) analysis was conducted subjected to comprehensive axial and rotational loads. It has been observed that the maximum deformation (8.1252 mm) and maximum stress (3179.9 Mpa) have been more in the case of the screws placed at 45° to the long bone axis than the screws normal to the long bone axis.