title: The characteristics of scoliosis in Prader-Willi syndrome (PWS): analysis of 58 scoliosis patients with PWS.
abstract: BACKGROUND
  The purpose of this study was to compare the characteristics of scoliosis in Prader-Willi syndrome (PWS) patients versus idiopathic scoliosis (IS).
  
  
  METHODS
  We identified 193 PWS patients. Scoliosis was found in 58 PWS patients, 39 of whom were treated with GH. Fifty-five IS patients were consecutively selected from an outpatient clinic. We investigated 113 patients (58 PWS group, 55 IS group) followed for a minimum of 2 years. The mean age was 17.9 and 16.1 years, respectively. Deformity was measured using Lenke classification, Cobb angle, thoracic kyphosis at T2-5 and T5-12, lumbar lordosis at T12-S1, and sagittal alignment at the C7 plumb line. BMI was also recorded.
  
  
  RESULTS
  According to the Lenke system, patients were classified as (PWS group/IS group): Type 1 (8/26), Type 2 (1/4), Type 3 (3/15), Type 4 (1/0), Type 5 (32/8), and Type 6 (13/2). The average Cobb angles were 32.6° in the PWS and 35.4° in the IS. No significant differences were found for the thoracic kyphosis (T2-5, T5-12), lumbar lordosis (T12-S1) or C7 plumb line between the two groups. BMI was increased in the PWS group not treated previously with GH as compared with the IS group and the PWS group with GH.
  
  
  CONCLUSIONS
  Most PWS patients presented with lumbar or thoracolumbar curves (Type 5, 6), whereas IS patients typically had thoracic scoliosis (Type 1, 2, 3).
authors.affiliation: Department of Orthopaedic Surgery, Dokkyo Medical University Koshigaya Hospital, 2-1-50 Minami-Koshigaya, Koshigaya, Saitama, 343-8555, Japan, nakayuta@dokkyomed.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Murakami
authors.forename: Takahiro
authors.initials: T
authors.lastname: Iida
authors.forename: Satoru
authors.initials: S
authors.lastname: Ozeki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Asano
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nohara
authors.forename: Toshiro
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D011218:Prader-Willi Syndrome / Q000150:complications* / Q000175:diagnosis* / Q000628:therapy; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000628:therapy; D012720:Severity of Illness Index; D013904:Thoracic Vertebrae; D055815:Young Adult