An Optimization Study Focused on Lattice Structured Custom Arm Casts for Fractured Bones Inspiring Additive Manufacturing

In case of fractures, cracks or damage to bone tissues, it is important to use casts, fixatives and protective equipment. Especially in cases where long-term use of casts is required, soft tissue wounds may occur in the human body due to their moisture and airtight structure. For this reason, the use of casts with custom designs, breathable materials, and high mechanical properties has become widespread in recent years. This study focuses on the design of custom arm casts using advanced additive manufacturing technologies and lightweight materials. By utilizing Voronoi lattice structures and hexagonal surface meshes, optimized designs adaptable to additive manufacturing were obtained from a standard arm cast. All cast geometries were investigated under 196 N and 380 N forces. Then, the impact of a 100 g and 1000 g concrete piece with a speed of 12.5 m/s on the arm cast was investigated. As a result of the analyzes, stress, impact plate velocities, deformation, strain and deformation energy were evaluated. The results showed that the designed arm casts have up to 60% better impact strength compared to conventional arm casts. Based on the findings of this study, the use of custom arm casts with optimized lattice structures designed for additive manufacturing will demonstrate high performance.