1 Department of Orthopedic Surgery, Institute for Locomotion, Aix-Marseille University, Sainte-Marguerite Hospital, 270, boulevard Sainte-Marguerite, 13009, Marseille, France.
2 Guys and St, Thomas' Hospitals, London, England.
3 Department of Anesthesiology, Aix-Marseille University, Marseille, France.
4 Department of Orthopedic Surgery, Institute for Locomotion, Aix-Marseille University, Sainte-Marguerite Hospital, 270, boulevard Sainte-Marguerite, 13009, Marseille, France. jean-noel.argenson@ap-hm.fr.