Hans-Rudolf Weiss1*
, Stefano Negrini2*
, Martha C Hawes3*
, Manuel Rigo4
, Tomasz Kotwicki5
, Theodoros B Grivas6
, Toru Maruyama7
and members of the SOSORT 
1
Asklepios Katharina Schroth Spinal Deformities Rehabilitation Centre, Bad Sobernheim, Germany
2
ISICO (Italian Scientific Spine Institute), Milan, Italy
3
University of Arizona, Tucson AZ 85721, USA
4
Instituto Èlena Salvá, Barcelona, Spain
5
University of Medical Sciences, Poznan, Poland
6
Orthopaedic Department "Thriasion" General Hospital, Magula, Athens, Greece
7
Department of Orthopaedic Surgery, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan