E. Carlos Rodríguez-Merchán is a Specialist in Orthopedic Surgery and a Consultant Orthopedic Surgeon currently working at the Department of Orthopedic Surgery, La Paz University Hospital, Madrid, Spain. He graduated from Complutense University with a degree in Medicine and Surgery in 1974, and subsequently completed a PhD in Medicine and Surgery. He is a former Associate Professor of Orthopedics at the Autonomous University of Madrid. Dr. Rodríguez-Merchán is the author of more than 250 articles in peer-reviewed, PubMed-listed journals, as well as ten books.Primitivo Gómez-Cardero earned his degree in Medicine and Surgery at the University of Valladolid, Spain, in 1991. He is Specialist in Orthopedic Surgery and Consultant Orthopedic Surgeon at the Department of Orthopedic Surgery, La Paz University Hospital, Madrid, Spain. Dr. Gómez-Cardero is the author of 18 articles published in PubMed-listed journals.