A novel logarithmic spiral design for proximal interphalangeal joint arthroplasty

This study evaluated a novel implant for proximal interphalangeal (PIP) joint arthroplasty that we designed according to the principles of a logarithmic spiral. The design addresses the limitations of current implants that poorly replicate natural finger kinematics. Finite element analysis and cadaver studies, including biomechanical and kinematic analyses, were conducted. Results showed that our implant had consistent sliding displacement, maintained consistent articular surface spacing, and was able to achieve a flexion arc greater than 90°, all while maintaining consistent contact throughout joint motion. In both simulation and cadaveric models, our implant demonstrates improved biomechanics by better replicating anatomical finger joint motion through its logarithmic spiral design that can potentially improve clinical outcomes for patients undergoing PIP joint arthroplasty.