Practical bending-angle calculation for an automated surgical plate bending apparatus

Surgical plates used for reconstructive surgery require a repetitive manual bending process to fit the plate to the defect during reconstruction. However, this process may not produce a plate that fits well, and repetitive bending may significantly increase the risk of plate fracture due to the accumulation of residual stress. In this study, the input angle is calculated using a proposed finite element process that considers the spring-back effect and improves the accuracy of the bending results without the need for repetitive bending. Bending tests for two arbitrary target angles (15° and 30°) are performed using the apparatus to demonstrate its effectiveness. Accurately bent plates are obtained from a single bending trial, unlike the use of another input angle that does not consider spring-back. Therefore, the proposed bending procedure could potentially replace the repetitive manual bending process and reduce the residual stress within the plate, thus lowering the risk of plate failure.