aDepartment of Orthopaedic Surgery and Traumatology, Hospital Universitario 12 de Octubre, Madrid, Spain

bDepartment of Orthopaedic Surgery and Traumatology, The Royal London Hospital, London, UK

cCentre for Neuroscience, Surgery and Trauma, Blizard Institute, Queen Mary University of London, UK

Financial Disclosure: The authors declare no conflicts of interest.

We declare that this work has not been sent to any other journal, congress or similar.

J.M.G.L. wrote the first draft of the manuscript. Jorge Gómez Alcaraz reviewed and edited the manuscript and approved the final version of the manuscript. J.C.G.d.l.B. reviewed and edited the manuscript and approved the final version of the manuscript. A.D.I. reviewed and edited the manuscript and approved the final version of the manuscript.

Correspondence to Jose Maria Garcia Lopez, MD, Resident Hospital 12 de Octubre Servicio de Traumatologia y Cirugia Ortopedica Madrid, Madrid SPAINTel: +34671067652; e-mail: [email protected]