[1] Bournemouth Univ, Orthopaed Res Inst, Bournemouth, Dorset, England
[2] Hosp Special Surg, Dept Anaesthesiol Crit Care & Pain Management, 535 E 70th St, New York, NY 10021 USA
[3] Weill Cornell Med Coll, Dept Healthcare Policy & Res, New York, NY USA
[4] Paracelsus Med Univ, Dept Anaesthesiol Perioperat Med & Intens Care Me, Salzburg, Austria
[5] Univ Copenhagen, Sect Surg Pathophysiol, Rigshosp, Copenhagen, Denmark
[6] Lundbeck Fdn Ctr Fast Track Hip & Knee Replacemen, Copenhagen, Denmark