Three-Dimensional Spinal Morphology Can Differentiate Between Progressive and Nonprogressive Patients With Adolescent Idiopathic Scoliosis at the Initial Presentation

Study Design. This is a prospective case-control study. Objective. The objective of this study was to compare 3-dimensional (3D) morphological parameters of the spine at the first visit between a nonprogressive (NP) and a progressive (P) group of immature adolescent idiopathic scoliosis (AIS). Summary of Background Data. Prediction of curve progression remains challenging in AIS at the first visit. Prediction of progression is based on curve type, curve magnitude, and skeletal or chronological age. Methods. A prospective cohort of 133 AIS was followed from skeletal immaturity to maturity (mean, 37 mo). The first group was made up of patients with AIS with a minimum 6-degree progression of the major curve between the first and last follow-up (P) (n = 53) and the second group was composed of patients with NP who reached maturity with less than 6-degree progression (n = 81). Computerized measurements were taken on reconstructed 3-dimensional (3D) spine radiographs of the first visit. There were 6 categories of measurements: angle of plane of maximum curvature, Cobb angles (kyphosis, lordosis), 3D wedging (apical vertebra, apical disks), rotation (upper and lower junctional vertebra, apical vertebra, and thoracolumbar junction), torsion, and slenderness (height/width ratio). t tests were also conducted. Results. There was no statistical difference between the 2 groups for age and initial Cobb angle. P presented significant hypokyphosis, and parameters related to rotation presented significant statistical differences between NP and P (plane of maximal curvature, torsion, and apical axial rotation). Depth slenderness also presented statistical differences. Conclusion. This study confirms that even at the initial visit, 3D morphological differences exist between P and NP AIS. It supports the use of 3D reconstructions of the spine in the initial evaluation of AIS to help predict outcome. Level of Evidence: 3

[1]  J A Miller,et al.  The length and proportions of the thoracolumbar spine in children with idiopathic scoliosis. , 1981, Acta orthopaedica Scandinavica.

[2]  Tsz Ping Lam,et al.  A Meta-Analysis of the Clinical Effectiveness of School Scoliosis Screening , 2010, Spine.

[3]  Nicolas Champain Recherche des facteurs biomécaniques dans l'aggravation des scolioses idiopathiques , 2004 .

[4]  M. Vitale,et al.  Does ScoliScore Provide More Information Than Traditional Clinical Estimates of Curve Progression? , 2012, Spine.

[5]  J. Pruijs,et al.  Variation in Cobb angle measurements in scoliosis , 1994, Skeletal Radiology.

[6]  P. Dangerfield,et al.  Relative anterior spinal overgrowth in adolescent idiopathic scoliosis—result of disproportionate endochondral-membranous bone growth? , 2005, European Spine Journal.

[7]  W. P. Bunnell,et al.  The Natural History of Idiopathic Scoliosis Before Skeletal Maturity , 1986, Spine.

[8]  J. M. Carlson,et al.  The prediction of curve progression in untreated idiopathic scoliosis during growth. , 1984, The Journal of bone and joint surgery. American volume.

[9]  Hubert Labelle,et al.  Seeing the Spine in 3D: How Will It Change What We Do? , 2011, Journal of pediatric orthopedics.

[10]  W Skalli,et al.  3D reconstruction of the spine from biplanar X-rays using parametric models based on transversal and longitudinal inferences. , 2009, Medical engineering & physics.

[11]  R. Porter Idiopathic scoliosis: the relation between the vertebral canal and the vertebral bodies. , 2000, Spine.

[12]  David Mitton,et al.  Fast accurate stereoradiographic 3D-reconstruction of the spine using a combined geometric and statistic model. , 2004, Clinical biomechanics.

[13]  Hubert Labelle,et al.  Three-dimensional Spine Parameters Can Differentiate Between Progressive and Nonprogressive Patients With AIS at the Initial Visit: A Retrospective Analysis , 2013, Journal of pediatric orthopedics.

[14]  H Labelle,et al.  Progression of Vertebral and Spinal Three-Dimensional Deformities in Adolescent Idiopathic Scoliosis: A Longitudinal Study , 2001, Spine.