title: The association of patient characteristics and spinal curve parameters with Lenke classification types.
abstract: METHODS
  Retrospective review.
  
  
  OBJECTIVE
  To determine the association of patient characteristics and spinal curve parameters with Lenke curve types.
  
  
  BACKGROUND
  The Lenke curve classification may be used for surgical planning and clinical research.
  
  
  METHODS
  We retrospectively reviewed the records of 1912 patients with adolescent idiopathic scoliosis who underwent initial surgery at 21 years of age or younger; collected data on patient's age, patient's sex, primary curve magnitude (<50°, 50°-75°, and .75°), and Scoliosis Research Society (SRS) outcomes questionnaire (SRS-22) score; and compared that data by Lenke curve type. Analysis of variance and χ tests were used as appropriate (significance level, P ≤ 0.005). RESULTS.: Lenke types vary by sex: male patients had more major thoracic (types 1-4) than major thoracolumbar/lumbar (types 5 and 6) curves, fewer lumbar C-modifiers (32% vs. 44%), and less apical lumbar translation (1.1 vs. 1.7 cm). Lenke types vary by frequency: the most common type was 1 (50%); the least common, 4 (4%). Lenke types vary by magnitude: type 4 had the greatest percentage of large curves (52% of curves .75°), most smaller curves were types 1 and 5, and type 4 had the largest mean magnitude (78° ± 17°). Lenke types vary by patient age: type 5 curves occurred in the oldest patients (average age at surgery: 15.4 ± 2.2 vs. 14.3 ± 14.6 years for all others) despite having the lowest mean magnitude (P = 0.001); curve size was negatively correlated with age at surgery (r = -0.16, P = 0.001). Lenke types vary by patient self-image: patients with type 4 curves had lower preoperative SRS outcome scores for self-image than did patients with type 1 curves (P = 0.005).
  
  
  CONCLUSIONS
  Lenke types vary by sex, frequency magnitude, patient age, and patient self-image, which should be considered in designing studies.
authors.affiliation: Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, MD 21224, USA. ehenze1@jhmi.edu
authors.forename: Paul D
authors.initials: PD
authors.lastname: Sponseller
authors.forename: John M
authors.initials: JM
authors.lastname: Flynn
authors.forename: Peter O
authors.initials: PO
authors.lastname: Newton
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Marks
authors.forename: Tracey P
authors.initials: TP
authors.lastname: Bastrom
authors.forename: Maty
authors.initials: M
authors.lastname: Petcharaporn
authors.forename: Mark J
authors.initials: MJ
authors.lastname: McElroy
authors.forename: Baron S
authors.initials: BS
authors.lastname: Lonner
authors.forename: Randal R
authors.initials: RR
authors.lastname: Betz
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D000367:Age Factors; D000704:Analysis of Variance; D001828:Body Image; D016009:Chi-Square Distribution; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000145:classification / Q000000981:diagnostic imaging* / Q000523:psychology / Q000601:surgery; D012720:Severity of Illness Index; D012737:Sex Factors; D011795:Surveys and Questionnaires; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D014481:United States; D055815:Young Adult