Design and Analysis of a Rigid-Flexible Combined Fracture Reduction Robot

To address the technical bottlenecks of minimally invasive closed reduction and intramedullary nailing (IMN), a rigid-flexible hybrid minimally invasive fracture reduction robot is proposed. The system leverages the compliant contact properties and continuous deformation capabilities of soft materials to ensure reduction accuracy while satisfying the compliance and safety requirements of the fracture reduction process. Additionally, based on the anatomical and physiological characteristics of the human lower limbs, a femoral shaft fracture model was developed, accounting for the presence of soft tissues such as muscles around the fracture site. Subsequently, fracture reduction experiments were conducted on the model following clinical surgical reduction protocols. After reduction, the maximum angular error was 0.6°, and the maximum residual translation was 1.0 mm. Results demonstrate that the proposed system meets the clinical functional reduction criteria, ensuring precision while enhancing human-robot interaction safety. It exhibits potential advantages in meeting the demands oflow radiation, lightweight design, and high compliance in fracture reduction surgeries.