1. Center of Experimental Orthopaedics Saarland University Kirrberger Straße 100, Building 37 Homburg Saar D‐66421 Germany
2. Cartilage Net of the Greater Region Kirrberger Straße 100, Building 37 Homburg Saar D‐66421 Germany
3. Clinique d'Eich Centre Hospitalier de Luxembourg 78 Rue d'Eich Luxembourg 1460 Luxembourg