title: Dynamic degenerative lumbar spondylolisthesis: diagnosis with axial loaded magnetic resonance imaging.
abstract: METHODS
  Retrospective review of case notes and imaging.
  
  
  OBJECTIVE
  To show the advantage of axial loaded magnetic resonance imaging (MRI) for identification of dynamic degenerative spondylolisthesis as a suspected cause of spinal claudication.
  
  
  BACKGROUND
  Degenerative spondylolisthesis typically occurs at L4/L5 and is usually evident on plain radiography. However, dynamic degenerative spondylolisthesis may become evident on erect radiographs when not shown on supine radiographs or MRI.
  
  
  METHODS
  The case notes and imaging (radiography, conventional MRI, and axial loaded MRI) in 2 patients with symptoms of spinal claudication were reviewed.
  
  
  RESULTS
  A 44-year-old female presented with a 3-year history of intermittent low back pain and right leg numbness after a fall. A 52-year-old female presented with a 4-year history of low back pain, bilateral leg weakness, and right leg numbness. In both cases, conventional MRI studies showed mild-to-moderate degenerative disc disease only with no evidence of abnormal spinal alignment or nerve root compression. Axial loaded MRI clearly showed the development of a degenerative spondylolisthesis with central canal stenosis and facet ganglion formation in 1 case.
  
  
  CONCLUSIONS
  Axial loaded MRI identified occult dynamic degenerative spondylolisthesis, which correlated with the clinical picture but was not shown on initial conventional MRI or plain radiography.
authors.affiliation: Department of Spinal Surgery, The Royal National Orthopaedic Hospital, Middlesex, United Kingdom. pjay007@doctors.org.uk
authors.forename: Prakash
authors.initials: P
authors.lastname: Jayakumar
authors.forename: Colin
authors.initials: C
authors.lastname: Nnadi
authors.forename: Asif
authors.initials: A
authors.lastname: Saifuddin
authors.forename: Emer
authors.initials: E
authors.lastname: Macsweeney
authors.forename: Adrian
authors.initials: A
authors.lastname: Casey
mesh_terms: D000328:Adult; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D007383:Intermittent Claudication / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D026741:Physical Therapy Modalities; D011859:Radiography / Q000379:methods; D012189:Retrospective Studies; D013123:Spinal Fusion; D013168:Spondylolisthesis / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D016474:Weight-Bearing