[1] Royal Newcastle Ctr, Newcastle Bone & Joint Inst, Newcastle, NSW 2300, Australia
[2] Univ Newcastle, Fac Hlth Sci, Callaghan, NSW 2308, Australia
[3] Canberra Hosp, Pain Management Unit, Woden, ACT, Australia
[4] Australian Natl Univ, Sch Med, Canberra, ACT, Australia