title: Factors affecting curve flexibility in skeletally immature and mature idiopathic scoliosis.
abstract: BACKGROUND
  The determination of factors affecting curve flexibility is important in idiopathic scoliosis patients with regard to the Risser sign. The objective of this retrospective study was to identify factors affecting curve flexibility in patients with skeletally immature and mature idiopathic scoliosis.
  
  
  METHODS
  The records of all patients with idiopathic scoliosis who received surgical treatment from July 2001 to August 2008 at our hospital were screened. The Risser sign was used to separate the patients into a skeletally mature group (Risser grade = 5) and skeletally immature group (Risser grade < 5). Data recorded and compared were flexibility (%), bending angle (°), apical vertebral rotation (°), Cobb angle (°), curve location, prior use of brace treatment, and number of vertebrae in the curve.
  
  
  RESULTS
  The study cohort consisted of 217 patients (34 males, 183 females) in the Risser grade < 5 group and 124 (21 males, 103 females) in the Risser grade = 5 group. Multiple linear regression analysis revealed that the Cobb angle and the curve location significantly affected curve flexibility in the Risser grade < 5 group, whereas in the Risser grade = 5 group, Cobb angle and age significantly affected flexibility.
  
  
  CONCLUSIONS
  Cobb angle and curve location influence main curve flexibility in skeletally immature adolescent idiopathic scoliosis, and Cobb angle and age influence curve flexibility in skeletally mature adult scoliosis. Measurement of these values may aid in the evaluation of treatment options and preoperative planning.
authors: Department of Orthopaedic Surgery, The Affiliated Changhai Hospital of the Second Military Medical University, No. 168, Changhai Rd., Yangpu District, Shanghai, 200433, China.
authors: Zi-Qiang
authors: ZQ
authors: Chen
authors: Yong-Fei
authors: YF
authors: Zhao
authors: Yu-Shu
authors: YS
authors: Bai
authors: Ka Po Gabriel
authors: KP
authors: Liu
authors: Shi-Sheng
authors: SS
authors: He
authors: Chuan-Feng
authors: CF
authors: Wang
authors: Jing-Tao
authors: JT
authors: Zhang
authors: Ming
authors: M
authors: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology*; D001915:Braces; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000295:instrumentation; D011379:Prognosis; D012372:ROC Curve; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D012720:Severity of Illness Index; D013131:Spine / Q000254:growth & development*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055815:Young Adult