1. Department of Orthopaedic Surgery, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA
2. Department of Orthopaedic Surgery, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam University Medical Centers, Amsterdam, the Netherlands
3. Department of Orthopaedics & Trauma Surgery, Flinders Medical Centre and Flinders University, Adelaide SA Australia
4. Division of Palliative Care & Geriatric Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
5. Department of Orthopaedic Surgery, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands