title: Limited usefulness of traction-compression films in the radiographic diagnosis of lumbar spinal instability. Comparison with flexion-extension films.
abstract: METHODS
  A prospective, within-patient comparison of two methods for functional radiography of lumbar spine with consecutive patients.
  
  
  OBJECTIVE
  To evaluate the usefulness of traction-compression radiography compared with conventional flexion-extension radiography in diagnosis of lumbar spinal instability.
  
  
  BACKGROUND
  Flexion-extension radiography generally is used and widely recognized as an effective method for diagnosis of segmental lumbar spinal instability, but the usefulness and findings of traction-compression films are less well known.
  
  
  METHODS
  Flexion-extension and traction-compression radiography were performed on 306 consecutive patients (mean age, 43 years; range, 14-68 years) with clinically suspected lumbar spinal instability. Radiography was performed of each patient in an upright position. Axial traction was accomplished by letting the patient hang by his or her hands from a horizontal bar. Compression views were taken when the patient had sandbags of approximately 30% of the his or her weight on the shoulders. Main interest was translational forward and backward displacement of one vertebra on another.
  
  
  RESULTS
  Signs of translational instability were present on the functional radiographs of 27% (84 of 306) of the patients. In diagnosis of instability, the overall agreement of flexion-extension and traction-compression films was only 0.786, and also statistic Kappa remained poor (0.05). Flexion-extension films more frequently revealed signs of instability than traction-compression films: 81 versus seven patients.
  
  
  CONCLUSIONS
  Traction-compression films seem to be of questionable value in diagnosis of lumbar spinal instability.
authors.affiliation: Department of Clinical Radiology, Kuopio University Hospital, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Pitkänen
authors.forename: H I
authors.initials: HI
authors.lastname: Manninen
authors.forename: K A
authors.initials: KA
authors.lastname: Lindgrer
authors.forename: M
authors.initials: M
authors.lastname: Turunen
authors.forename: O
authors.initials: O
authors.lastname: Airaksinen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017116:Low Back Pain / Q000000981:diagnostic imaging / Q000209:etiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008161:Lumbosacral Region / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D013122:Spinal Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016474:Weight-Bearing / Q000502:physiology