title: Failure of standard imaging to detect a cervical fracture in a patient with ankylosing spondylitis.
abstract: METHODS
  Retrospective case study of 38-year-old male with ankylosing spondylitis who presented with a Brown-Séquard syndrome following a fall and an occult fracture on initial spinal imaging studies.
  
  
  OBJECTIVE
  To review the recommended imaging protocol in a patient with ankylosing spondylitis and a suspected cervical spine fracture.
  
  
  BACKGROUND
  Plain radiographic imaging using orthogonal views can detect the majority of spinal fractures. However, fracture identification is particularly difficult in patients with ankylosing spondylitis. Of the various contemporary imaging methods, [magnetic resonance imaging (MRI), computed tomography (CT), nuclear scanning] high-definition multidetector CT scanning is the most useful in identifying subtle fractures, but in metabolic bone diseases the utility of these methods is unknown.
  
  
  METHODS
  Retrospective radiographic evaluation of imaging studies of ankylosing spondylitis patient with occult fracture by five spine surgeons and neuroradiologists, followed with detailed review and interpretation of literature concerning present radiology techniques and methods to isolate occult fractures.
  
  
  RESULTS
  Initial imaging studies, including plain radiographs of the spinal axis, cervical and thoracic single-detector CT with reconstructed images, and MRI, were unremarkable in detecting an occult cervical spine fracture in a patient with ankylosing spondylitis and a spinal cord injury following a fall. The patient was placed empirically in a halo orthosis and a high definition multidetector CT scan was obtained. This study demonstrated a transverse fracture through the fused C6-C7 spinal level.
  
  
  CONCLUSIONS
  Occult fractures in ankylosing spondylitis may not be apparent on routine plain radiographic and MRI studies. In the setting of ankylosing spondylitis, a high index of suspicion must be maintained in all patients presenting with spinal pain following even minor trauma. High-resolution multidetector CT imaging appears to be more sensitive and accurate in the diagnosis of fractures in this patient subgroup than other contemporary imaging methods.
authors: Department of Neurosurgery, Jefferson Medical College, Philadelphia, Pennsylvania, USA. James.Harrop@jefferson.edu
authors: James S
authors: JS
authors: Harrop
authors: Ashwini
authors: A
authors: Sharan
authors: Greg
authors: G
authors: Anderson
authors: Alan S
authors: AS
authors: Hillibrand
authors: Todd J
authors: TJ
authors: Albert
authors: Adam
authors: A
authors: Flanders
authors: Alexander R
authors: AR
authors: Vaccaro
mesh_terms: D000328:Adult; D018437:Brown-Sequard Syndrome / Q000000981:diagnostic imaging / Q000209:etiology; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000592:standards; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013119:Spinal Cord Injuries / Q000000981:diagnostic imaging / Q000209:etiology; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000209:etiology*; D013167:Spondylitis, Ankylosing / Q000150:complications* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000592:standards