title: EOS suspension test for the assessment of spinal flexibility in adolescent idiopathic scoliosis.
abstract: BACKGROUND
  The assessment of spinal flexibility is essential for the planning of adolescent idiopathic scoliosis (AIS) surgery. Various radiographic methods have been used but none of them has shown any superiority. The new low-dose stereography system EOS (EOS imaging, Paris, France) captures whole body images in a single scan without vertical distortion. EOS is now used in routine clinical use for AIS follow-up. The aim of this study was to prospectively evaluate the feasibility and the reproducibility of a new suspension test during the EOS imaging for the assessment of spinal flexibility in AIS.
  
  
  METHODS
  Fifty AIS patients scheduled for surgery were prospectively included. For each patient, a standard EOS radiograph was obtained, then a suspension test in the EOS and a classic traction test on the cotrel frame were performed. The examinations were compared in terms of radiation exposure, tolerance, mean traction force, and Cobb angle reduction for each curve. Axial and sagittal reductions during suspension were analyzed on three-dimensional EOS reconstructions.
  
  
  RESULTS
  The tolerance of the suspension test was lower than the traction test but it was less operator dependent. Radiation exposure was 7 times lower during the suspension test. Cobb angle reductions achieved in the proximal and main curves by the two tests were similar. The traction test achieved greater reduction of the distal curve. Flexibility in the axial plane and in the sagittal plane was analyzed with the suspension test. The reduction in apical rotation was not correlated with the reduction in Cobb angle.
  
  
  CONCLUSIONS
  The EOS suspension test can be used for the assessment of spinal flexibility in AIS. It gives a global vision of the deformity with new flexibility indices in the axial and sagittal planes.
authors: Pediatric Orthopedic Department, Robert Debré Hospital, APHP, University Paris Diderot, 48 bld Serrurier, 75019, Paris, France, carohirsch@yahoo.fr.
authors: Caroline
authors: C
authors: Hirsch
authors: Brice
authors: B
authors: Ilharreborde
authors: Keyvan
authors: K
authors: Mazda
mesh_terms: D000293:Adolescent; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D010780:Photogrammetry; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012600:Scoliosis / Q000503:physiopathology*; D013131:Spine / Q000473:pathology*; D014143:Traction
references: J Radiol Prot. 2013 Sep;33(3):621-33
references: 23803575
references: Clin Orthop Relat Res. 1982 Jan-Feb;(162):47-53
references: 7067232
references: Spine (Phila Pa 1976). 2004 Oct 15;29(20):2284-9
references: 15480143
references: Spine (Phila Pa 1976). 2000 Jan;25(1):76-81
references: 10647164
references: J Bone Joint Surg Am. 2001 Aug;83-A(8):1169-81
references: 11507125
references: Eur Spine J. 2013 Jun;22(6):1362-7
references: 23543370
references: J Spinal Disord Tech. 2012 Aug;25(6):E161-6
references: 22576722
references: Skeletal Radiol. 1994 Oct;23 (7):517-20
references: 7824978
references: Spine (Phila Pa 1976). 2009 Mar 15;34(6):591-7
references: 19282738
references: Spine (Phila Pa 1976). 2005 Jul 15;30(14 ):1637-42
references: 16025034
references: Eur Spine J. 2014 Dec;23(12):2619-25
references: 24875382
references: Spine (Phila Pa 1976). 2007 Nov 15;32(24):2641-3
references: 18007238
references: Rev Chir Orthop Reparatrice Appar Mot. 1964 Jan-Feb;50:59-75
references: 14139818
references: Spine (Phila Pa 1976). 1996 Nov 1;21(21):2469-73
references: 8923633
references: Spine (Phila Pa 1976). 2011 Sep 15;36(20):E1306-13
references: 21697768
references: Spine (Phila Pa 1976). 2001 Mar 1;26(5):E74-9
references: 11242396
references: JAMA Pediatr. 2013 Aug 1;167(8):700-7
references: 23754213
references: J Pediatr Orthop. 2011 Jan-Feb;31(1 Suppl):S37-45
references: 21173617
references: Spine (Phila Pa 1976). 2007 Nov 15;32(24):2668-72
references: 18007242
references: J Bone Joint Surg Am. 1997 Aug;79(8):1144-50
references: 9278073
references: Spine J. 2014 Sep 1;14 (9):1984-90
references: 24333453
references: Spine (Phila Pa 1976). 2004 Nov 1;29(21):2466-70
references: 15507812
references: Spine (Phila Pa 1976). 2008 Sep 15;33(20):2192-8
references: 18794761
references: Spine (Phila Pa 1976). 2012 Jul 15;37(16):1391-7
references: 22415001
references: Eur Spine J. 2014 Jul;23 Suppl 4:S397-405
references: 24811688
references: J Spinal Disord Tech. 2011 Oct;24(7):437-43
references: 21336177
references: Spine (Phila Pa 1976). 2010 May 20;35(12 ):E530-4
references: 20445468
references: Spine (Phila Pa 1976). 1998 Apr 1;23 (7):804-8
references: 9563111