title: Sensitivity of magnetic resonance imaging in the diagnosis of mobile and nonmobile L4-L5 degenerative spondylolisthesis.
abstract: BACKGROUND
  Lumbar degenerative spondylolisthesis (LDS) is often diagnosed by conventional supine magnetic resonance imaging (MRI). Numerous studies have shown, however, that the degree of spondylolisthesis can be reduced or disappears when the patient is supine as compared with standing lateral and flexion-extension (SLFE) radiographs.
  
  
  OBJECTIVE
  To compare the sensitivity of supine MRI with SLFE radiographs in patients with L4-L5 LDS.
  
  
  METHODS
  A retrospective imaging study.
  
  
  METHODS
  Included patients diagnosed with L4-L5 LDS with both SLFE films and supine MRI.
  
  
  METHODS
  Lumbar degenerative spondylolisthesis was defined radiographically as a slip greater than 4.5 mm. Mobile LDS was defined as a difference of greater than 3% in slip percentage between lateral radiographs and sagittal MRIs. Additional measurements included L4-L5 facet effusion diameter on axial MRIs. Measurements were performed by two independent examiners. The kappa coefficient was used to assess the interobserver agreement.
  
  
  RESULTS
  Of 103 patients assessed, 68% were women and the average age was 66 years. Lumbar degenerative spondylolisthesis was seen on 101 (98%) lateral films and 80 (78%) MRIs. Average slip was 10.0 mm for lateral standing radiographs and 6.6 mm on MRI (p<.0001). Fifty (48%) patients were identified with mobile LDS. The positive predictive value of facet joint effusion for mobile LDS increased from 52% for effusions greater than 1 mm to 100% for effusions greater than 3.5 mm.
  
  
  CONCLUSIONS
  This study found that MRI had a sensitivity of 78% for detecting L4-L5 LDS compared with 98% for lateral standing films. We also identified facet effusion size as a marker to predict mobile LDS. These findings suggest that, particularly in the setting of facet effusions, the complete workup of patients in whom LDS is possible should include standing radiographs.
authors.affiliation: Department of Orthopaedic and Neurological Surgery, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, USA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Kuhns
authors.affiliation: Department of Orthopaedic and Neurological Surgery, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, USA.
authors.forename: Shalen
authors.initials: S
authors.lastname: Kouk
authors.affiliation: Department of Orthopaedic and Neurological Surgery, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Neurological Surgery, The Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA.
authors.forename: Colin
authors.initials: C
authors.lastname: Buchanan
authors.affiliation: Department of Orthopaedic and Neurological Surgery, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Cleveland Clinic Lerner College of Medicine, 9500 Euclid Avenue NA21, Cleveland, OH 44195, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lubelski
authors.affiliation: Department of Orthopaedic and Neurological Surgery, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Alvin
authors.affiliation: Department of Orthopaedic and Neurological Surgery, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Neurological Surgery, The Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA; Cleveland Clinic Lerner College of Medicine, 9500 Euclid Avenue NA21, Cleveland, OH 44195, USA.
authors.forename: Edward C
authors.initials: EC
authors.lastname: Benzel
authors.affiliation: Department of Orthopaedic and Neurological Surgery, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Neurological Surgery, The Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA; Cleveland Clinic Lerner College of Medicine, 9500 Euclid Avenue NA21, Cleveland, OH 44195, USA. Electronic address: mrozt@ccf.org.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Mroz
authors.affiliation: Department of Orthopaedic Surgery, Washington Hospital Center, 110 Irving St Nw, Washington, DC 20010, USA.
authors.forename: James
authors.initials: J
authors.lastname: Tozzi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008161:Lumbosacral Region / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography; D016059:Range of Motion, Articular; D012680:Sensitivity and Specificity; D013168:Spondylolisthesis / Q000175:diagnosis* / Q000000981:diagnostic imaging
keywords: Degenerative spondylolisthesis; Diagnosis; Facet effusion; Imaging; MRI; SLFE