New method for medical devices design and manufacture: Case study—scapholunate implant

Abstract

The scapholunate interosseous ligament is located between the scaphoid and lunate bones and if it torns causes instability, leading to weakness in the hand, chronic pain, and lack of motion. While many treatment options are available, based on the type of instability, all of them present side effects including stiffness in the wrist, long recovery times, and widespread scarring. As such, wrist prostheses have been introduced as an alternative treatment. As suitable scapholunate prostheses implanted using arthroscopy are a promising option in reducing complications associated with conservative treatments, this work proposes a new implant designed to replace the scapholunate ligament. The implant is a completely new design, which was manufactured to determine its workability. Medical experts and engineers approved and validated the new design process, and the prototype obtained will be used to evaluate performance and to propose possible future improvements.