Influence of joint replacement on ipsi- and contralateral joint forces - long-term analysis of adaptations using in vivo measurement and simulation

• Applicants: Privatdozent Dr.-Ing. Philipp Damm; Professor Dr. Heiko Wagner
• Subject Area: Orthopaedics, Traumatology, Reconstructive Surgery ; Public Health, Healthcare Research, Social and Occupational Medicine
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564203605

Joint arthroplasty is one of the most common orthopedic surgeries worldwide. Despite the high success rate in older patients, younger and more active patients show significantly higher revision rates due to increased mechanical stress and the maintenance of sporting activities. Revision surgeries are cost-intensive and increase the risk of complications. This project aims to minimize stress-induced secondary diseases and premature failure of hip and knee endoprostheses using a patient-specific analysis of muscle and joint forces during everyday movements. The Julius Wolff Institute (JWI) has unique, extensive, and long-standing experience in in vivo load measurements with instrumented implants. These unique joint implants enable recording joint loads during everyday and sports activities. Moreover, the JWI can also perform simultaneous in vivo loading measurements on the hip and knee within a particularly active patient. In addition, the participating institutions have extensive expertise in computer modeling human movement using 3D muscle-skeleton models and the optimization of complex muscle activation. Retrospective analyses of already measured in vivo load data will be integrated into a new modeling tool, ComputerMyoGraphy (CMG), to predict the individual load changes after an operation precisely. The method will based on developing new adaptive optimization criteria considering musculoskeletal redundancy, including individual muscle contraction and joint stability. This enables a reliable prediction of the loads even under dynamic and unstable movement conditions. The project's secondary goal is to optimize rehabilitation strategies and reduce treatment costs through model-based approaches that can also be applied in prevention and occupational medicine. In the long term, the results should lead to an improved lifespan of implants and a higher quality of therapy. Another goal is to develop a freely accessible web tool for the publicly accessible in vivo load database Orthoload.com to analyze and visualize individual joint loads. Based on validated models, this tool can be used to create more precise therapy plans and significantly support technical innovations in orthopedics, trauma surgery, and occupational science. The project thus represents a significant step towards personalized therapy and clinical practice and provides a basis for integrating biomechanical findings into orthopedic care.

• DFG Programme: Research Grants