[1] Univ Autonoma Madrid UAM, IIS Fdn Jimenez Diaz, Dept Orthopaed Surg & Traumatol, Madrid 28049, Spain
[2] Krankenhaus Agatharied, Dept Traumatol & Orthopaed, D-83734 Hausham, Germany
[3] Schulthess Clin Zurich, Dept Shoulder & Elbow Surg, CH-8008 Zurich, Switzerland
[4] Charite Univ Med Berlin, Ctr Musculoskeletal Surg, Campus Virchow, D-10117 Berlin, Germany