Bone tissue damage resulting from trauma, tumor, or bone infection is one of the most common problems that humans face in everyday life. Tissue engineering is a developing method for the reconstruction and repair of damaged tissues, and a scaffold should have properties such as biocompatibility, mechanical properties suitable for the type of damaged tissue, and suitable surface characteristics for better cell adhesion. This study presents a precise and practical process for designing a scaffold used in bone tissue repair, such as the femur, and the effect of unit cell geometry on the mechanical properties and surface characteristics of the scaffold is investigated. CT scan images of the human femur area are obtained, and 3D models of the cortical and cancellous parts of the femur are constructed. The outer surface of the damaged parts is designed with ideal geometry; six types of unit cells with different geometries are designed, and the changes in the Young's modulus are determined as a function of changes in the unit cell porosity. The cubic–star-shaped unit cell is chosen as the suitable unit cell for the scaffold structure, with a side length of 0.88 mm and a pore size of 0.6 mm.
