title: Radiographic assessment of congenital C2-3 synostosis.
abstract: OBJECTIVE
  To evaluate the morphologies of congenital C2-3 synostosis in 25 patients.
  
  
  METHODS
  Radiographs of 11 males and 14 females aged 5 to 74 years with congenital C2-3 synostosis were reviewed. All cases were found incidentally on radiographs when presenting with neck/shoulder discomfort/pain.
  
  
  RESULTS
  13 of the patients had spondylosis in 21 segments: C1-2 (n=1) and C3-4 (n=1), C4-5 (n=7), C5-6 (n=9), and C6-7 (n=3). Of whom 12 had normal sagittal alignment and one had kyphotic synostosis (who developed compensatory hyperlordosis of the caudal mobile segments and subsequent spondylosis at C3-4 and C5 retrolisthesis). The remaining 12 patients had no spondylosis and had normal sagittal alignment, but had other associated pathologies including disc herniation at C3-4, C1 ring hypoplasia, and calcification of the nuchal ligament.
  
  
  CONCLUSIONS
  Normally aligned congenital synostosis of C2-3 is rarely associated with a junctional problem, whereas a kyphotic synostosis is associated with a caudal junctional problem. Spondylosis developing after age 40 years is not associated with C2-3 synostosis.
authors.affiliation: Department of Orthopaedic Surgery, Cheju Halla General Hospital, Jeju, Korea.
authors.forename: Myung-Sang
authors.initials: MS
authors.lastname: Moon
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Kim
authors.forename: Bong-Jin
authors.initials: BJ
authors.lastname: Lee
authors.forename: Jeong-Lim
authors.initials: JL
authors.lastname: Moon
authors.forename: Jin-Fu
authors.initials: JF
authors.lastname: Lin
authors.forename: Young-Wan
authors.initials: YW
authors.lastname: Moon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000151:congenital / Q000000981:diagnostic imaging*; D013580:Synostosis / Q000000981:diagnostic imaging*; D055815:Young Adult; D021801:Zygapophyseal Joint