Instrumentation of an in-vitro test bed for load testing of shoulder endoprosthesis prototypes

Abstract

Shoulder instability remains one of the major complications after total shoulder arthroplasty and reverse TSA. Prototypes of shoulder endoprostheses designed to tackle this problem were developed at the Ludwig Boltzmann Institute for Experimental and Clinical Traumatology. In this thesis the design and function of the shoulder simulator that was commissioned to test the prostheses are described. The simulator is an automated biaxial test bed that measures separation forces between the humerosocket and glenosphere in every physiological position of the glenohumeral joint, with a maximum load of 500 N. The mechanical apparatus is able to simulate two different decoupling mechanisms, along the sagittal plane and along the transverse plane, at different angles between the prosthesis partners. This thesis covers all steps of calculation, design and construction, but not the implementation of the software. The device is validated according to design, installation and operational qualification.