1. Clinica CEMTRO, Madrid, Spain
2. Hospital MAZ Zaragoza, Zaragoza, Spain
3. Hospital Universitari Bellvitge, L’Hospitalet de Llobregat, Barcelona, Spain
4. Traumatología y Cirugía Ortopédica, Hospital Universitario Ramon y Cajal, Madrid, Spain
5. Nouvelle Clinique de l'Union, Saint-Jean, France
6. Massachusetts General Hospital Yawkey Center for Outpatient Care, Boston, Massachusetts, USA