Mechanical performance comparison of two surgical constructs for wrist four-corner arthrodesis via dorsal and radial approaches

Background Four-corner arthrodesis, which involves fusing four carpal bones while removing the scaphoid bone, is a standard surgery for treatment of advanced stages wrist arthritis. Nowadays, it can be performed using dorsal approach by fixing plate to and new radial in development. To date, there no consensus on biomechanically optimal most reliable surgical construct four-corner arthrodesis. Methods evaluate them thus assist surgeon choosing best implant orientation, or dorsal, two different arthrodesis constructs were virtually simulated 3D finite element model representing all major structures wrist. Two realistic load sets applied model, common tasks elderly. Findings Results consistency was assessed comparing with literature force magnitude computed bones. The Von Mises stress distribution plates calculated. Stress concentration located at plate-screw interface both constructs, maximum value 413 MPa compared 326 plate, meaning that levels are more unfavourable approach. Interpretation Although some bending found one case, mechanically robust other case. Despite limitations, this study provides, first time, quantified evidence newly developed as efficient construct.