title: Early Detection of Progressive Adolescent Idiopathic Scoliosis: A Severity Index.
abstract: METHODS
  Early detection of progressive adolescent idiopathic scoliosis (AIS) was assessed based on 3D quantification of the deformity.
  
  
  OBJECTIVE
  Based on 3D quantitative description of scoliosis curves, the aim is to assess a specific phenotype that could be an early detectable severity index for progressive AIS.
  
  
  BACKGROUND
  Early detection of progressive scoliosis is important for adapted treatment to limit progression. However, progression risk assessment is mainly based on the follow up, waiting for signs of rapid progression that generally occur during the growth peak.
  
  
  METHODS
  Sixty-five mild scoliosis (16 boys, 49 girls, Cobb Angle between 10 and 20°) with a Risser between 0 and 2 were followed from their first examination until a decision was made by the clinician, either considering the spine as stable at the end of growth (26 patients) or planning to brace because of progression (39 patients). Calibrated biplanar x-rays were performed and 3D reconstructions of the spine allowed calculating six local parameters related to main curve deformity. For progressive curve 3D phenotype assessment, data were compared with those previously assessed for 30 severe scoliosis (Cobb Angle > 35°), 17 scoliosis before brace (Cobb Angle > 29°) and 53 spines of nonscoliosis subjects. A predictive discriminant analysis was performed to assess similarity of mild scoliosis curves either to those of scoliosis or nonscoliosis spines, yielding a severity index (S-index). S-index value at first examination was compared with clinical outcome.
  
  
  RESULTS
  At the first exam, 53 out of 65 predictions (82%) were in agreement with actual clinical outcome. Approximately, 89% of the curves that were predicted as progressive proved accurate.
  
  
  CONCLUSIONS
  Although still requiring large scale validation, results are promising for early detection of progressive curves.
  
  
  METHODS
  2.
authors: Arts et Metiers ParisTech, Institut de Biomecanique Humaine Georges Charpak, Paris, France.
authors: Wafa
authors: W
authors: Skalli
authors: Arts et Metiers ParisTech, Institut de Biomecanique Humaine Georges Charpak, Paris, France.|School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom.
authors: Claudio
authors: C
authors: Vergari
authors: Unite Rachis, CHU - Hopital Bellevue, Saint-Etienne, France.
authors: Eric
authors: E
authors: Ebermeyer
authors: Unite Rachis, CHU - Hopital Bellevue, Saint-Etienne, France.
authors: Isabelle
authors: I
authors: Courtois
authors: Arts et Metiers ParisTech, Institut de Biomecanique Humaine Georges Charpak, Paris, France.
authors: Xavier
authors: X
authors: Drevelle
authors: Department of Pediatric Orthopedics, Hospices Civils de Lyon, Claude Bernard Lyon 1 University, Lyon, France.
authors: Remi
authors: R
authors: Kohler
authors: Department of Pediatric Orthopedics, Hospices Civils de Lyon, Claude Bernard Lyon 1 University, Lyon, France.
authors: Kariman
authors: K
authors: Abelin-Genevois
authors: Arts et Metiers ParisTech, Institut de Biomecanique Humaine Georges Charpak, Paris, France.
authors: Jean
authors: J
authors: Dubousset
mesh_terms: D000293:Adolescent; D002648:Child; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D011859:Radiography; D012600:Scoliosis / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index; D013131:Spine / Q000000981:diagnostic imaging*