title: Reliability of a functional classification system in the monitoring of patients with idiopathic scoliosis.
abstract: METHODS
  Patients with scoliosis from 1999 to 2001 were monitored using radiographs and the Quantec Spinal Imaging System (Quantec) to validate the Functional Classification System (FCS) developed at Children's Hospital of Wisconsin (CHW).
  
  
  OBJECTIVE
  To determine the accuracy of the FCS.
  
  
  BACKGROUND
  The authors evaluated different noninvasive ways of evaluating the scoliotic spine. The FCS was developed as a means to predict the degree of scoliotic curve.
  
  
  METHODS
  Consecutive scoliosis visits (543) seen at CHW between 1999 and 2001 for initial or follow-up examination were investigated; of them, 157 had an radiograph within 6 months of Quantec. Subjects were placed into groups based on Cobb Angles. FCS classifications were compared to Cobb angle groupings and calculated sensitivity and specificity. Pearson's correlation coefficient was calculated for 39 subjects.
  
  
  RESULTS
  Sensitivity of the FCS for single curve groups ranged from 0.50 to 0.63 and specificity from 0.64 to 0.86. For double curve, both sensitivity and specificity ranged from 0.48 to 0.81. Pearson's correlation was statistically significant (r = 0.45, P < 0.05).
  
  
  CONCLUSIONS
  Sensitivity, specificity, and Pearson's correlation coefficient reflect the reliability of the Quantec method. Therefore, the FCS can be considered as a reliable tool for monitoring the progression of scoliosis with reduced need of radiographs.
authors.affiliation: Musculoskeletal Functional Assessment Center, Children's Hospital of Wisconsin, Medical College of WI, Milwaukee, WI 53201, USA.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Klos
authors.forename: Xue-Cheng
authors.initials: XC
authors.lastname: Liu
authors.forename: Roger M
authors.initials: RM
authors.lastname: Lyon
authors.forename: J Channing
authors.initials: JC
authors.lastname: Tassone
authors.forename: John G
authors.initials: JG
authors.lastname: Thometz
mesh_terms: D000293:Adolescent; D000328:Adult; D001415:Back / Q000473:pathology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004185:Disability Evaluation; D006801:Humans; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data; D008991:Monitoring, Physiologic / Q000379:methods* / Q000706:statistics & numerical data; D010780:Photogrammetry / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D011871:Radiology / Q000592:standards / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012600:Scoliosis / Q000145:classification* / Q000175:diagnosis* / Q000503:physiopathology; D013131:Spine / Q000473:pathology* / Q000503:physiopathology