1. ANCA Medical Center, Krijgslaan 181, 9000 Gent, Belgium.
2. J Vernon Luck Snr MD, Orthopaedic Research Center, Orthopaedic Hospital, 2400 S., Flower Street, UCLA, Los Angeles 90007, California, USA.
3. St. Helen’s Private Hospital, 186, Macquarie Street, Hobart, Tasmania 7000, Australia.
4. Department of Orthopaedic Surgery, Rush Presbyterian St Luke’s, Medical Center, Room 756, Cohn Research Building, 1735 West Harrison Street, Chicago, Illinois 60612-3833, USA.