title: Spinal cord dimensions in children with Klippel-Feil syndrome: a controlled, blinded radiographic analysis with implications for neurologic outcomes.
abstract: METHODS
  Retrospective case series.
  
  
  OBJECTIVE
  To evaluate the axial cross-sectional dimensions of the spinal cord and cerebrospinal fluid (CSF) column in children with Klippel-Feil Syndrome (KFS) versus an age-matched cohort of control subjects.
  
  
  BACKGROUND
  Neurologic sequelae and chronic pain are known to occur in KFS and factors implicated include spinal cord compression from canal stenosis, segmental instability, vascular disruption, and central nervous system abnormalities including tethered cord, syrinx, and diastomyelia. No study to date, however, has examined the role of spinal cord size as a contributing factor to neurologic sequelae in KFS.
  
  
  METHODS
  We retrospectively reviewed the plain radiographic, magnetic resonance imaging (MRI), and clinical records of 12 consecutive patients between 2 and 18 years with KFS (average age 9.5 +/- 5.3 years) and 14 age-matched controls (average age 8.3 +/- 5.1 year). For each patient, plain film radiography was reviewed to compare Torg ratios at each cervical level, and axial T1-weighted MRI was used to compare spinal cord and CSF column cross-sectional area calculations.
  
  
  RESULTS
  The Torg-Pavlov ratios were identical between the 2 groups (0.77 +/- 0.15 vs. 0.77 +/- 0.19). Analysis of axial T1-weighted MRI cross-sectional spinal cord area revealed that the cord was smaller in KFS patients at each level from C2-C7 compared with controls. These differences were statistically significant at C4 (P = 0.016), C5 (P = 0.035), and C6 (P = 0.032). Subset analysis of abnormal (fused) levels compared with controls revealed the same findings, although these differences were not significant due to the limited numbers available at each level. Analysis of the CSF column, however, revealed that overall the canal was slightly larger in KFS patients compared with controls, although this difference was not statistically significant. Four of the 12 KFS patients presented with neurologic symptoms, all of which improved after posterior cervical stabilization.
  
  
  CONCLUSIONS
  In our cohort of patients we have noted statistically significant differences in axial cord dimensions, with no differences in CSF column, suggesting that the cord size is smaller in KFS children compared with age-matched controls.
authors.affiliation: Department of Orthopaedic Surgery, The University of Pennsylvania, Philadelphia, PA 19104-4399, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Auerbach
authors.forename: Harish S
authors.initials: HS
authors.lastname: Hosalkar
authors.forename: Sharat K
authors.initials: SK
authors.lastname: Kusuma
authors.forename: Brian P D
authors.initials: BP
authors.lastname: Wills
authors.forename: John P
authors.initials: JP
authors.lastname: Dormans
authors.forename: Denis S
authors.initials: DS
authors.lastname: Drummond
mesh_terms: D000293:Adolescent; D001416:Back Pain / Q000000981:diagnostic imaging / Q000209:etiology*; D016022:Case-Control Studies; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D006801:Humans; D007714:Klippel-Feil Syndrome / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D009422:Nervous System Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D015588:Observer Variation; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D013116:Spinal Cord / Q000000981:diagnostic imaging* / Q000473:pathology