Hans-Rudolf Weiss* 1
, Stefano Negrini* 2
, Martha C Hawes* 3
, Manuel Rigo4
, Tomasz Kotwicki5
, Theodoros B Grivas6
, Toru Maruyama7
and members of the SOSORT 
1Asklepios Katharina Schroth Spinal Deformities Rehabilitation Centre, Bad Sobernheim, Germany
2ISICO (Italian Scientific Spine Institute), Milan, Italy
3University of Arizona, Tucson AZ 85721, USA
4Instituto Èlena Salvá, Barcelona, Spain
5University of Medical Sciences, Poznan, Poland
6Orthopaedic Department "Thriasion" General Hospital, Magula, Athens, Greece
7Department of Orthopaedic Surgery, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan