title: Grading Osteoarthritic Changes of the Zygapophyseal Joints from Radiographs: A Reliability Study.
abstract: OBJECTIVE
  This study tested the reliability of a 5-point ordinal scale used to grade the severity of degenerative changes of zygapophyseal (Z) joints on standard radiographs.
  
  
  METHODS
  Modifications were made to a Kellgren grading system to improve agreement for grading the severity of osteoarthritic changes in lumbar Z joints. These included adding 1 grade of no degeneration, multiple radiographic views, and structured examiner training. Thirty packets of radiographic files were obtained, which included representation of all 5 grades including no degeneration (0) and Kellgren's 4-point (1-4) joint degeneration classification criteria. Radiographs were digitized to create a radiographic atlas that was given to examiners for individual study and blinded evaluation sessions. Intrarater and interrater agreement was determined by weighted κ (κw) from the examination of 79 Z joints (25 packets).
  
  
  RESULTS
  Using the modified scale and after training, examiners demonstrated a moderate-to-substantial level of interrater agreement (κw = 0.57, 0.60, and 0.68). Intrarater agreement was moderate (κw = 0.42 and 0.54).
  
  
  CONCLUSIONS
  The modified Kellgren 5-point grading system provides acceptable intrarater and interrater reliability when examiners are adequately trained. This grading system may be a useful method for future investigations assessing radiographic osteoarthritis of the Z joints.
authors.affiliation: Assistant Professor, Center for Anatomical Science and Education, Department of Surgery, Saint Louis University School of Medicine, St Louis, MO.
authors.forename: Joshua W
authors.initials: JW
authors.lastname: Little
authors.affiliation: Instructor, Department of Clinical Sciences, National University of Health Sciences, Lombard, IL.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Grieve
authors.affiliation: Professor and Dean of Research, Research Department, National University of Health Sciences, Lombard, IL. Electronic address: gcramer@nuhs.edu.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Cramer
authors.affiliation: Radiologist, Northwestern Health Sciences University, Bloomington, MN.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Rich
authors.affiliation: Assistant Professor, National University of Health Sciences, Lombard, IL.
authors.forename: Evelyn E
authors.initials: EE
authors.lastname: Laptook
authors.affiliation: President, National University of Health Sciences, Lombard, Ill.
authors.forename: Joseph P D
authors.initials: JP
authors.lastname: Stiefel
authors.affiliation: Dean, Center for Life and Health Sciences, Mohawk Valley Community College, Utica, NY.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Linaker
mesh_terms: D001175:Arthrography / Q000379:methods; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D010003:Osteoarthritis / Q000145:classification* / Q000000981:diagnostic imaging* / Q000473:pathology; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods; D021801:Zygapophyseal Joint / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: Diagnostic Imaging; Lumbar Vertebrae; Osteoarthritis; Reliability; Spine; Zygapophyseal Joint