title: Reliable Magnetic Resonance Imaging Based Grading System for Cervical Intervertebral Disc Degeneration.
abstract: METHODS
  Observational.
  
  
  OBJECTIVE
  To develop a simple and comprehensive grading system for cervical discs that precisely, consistently and meaningfully presents radiologic and morphologic data.
  
  
  BACKGROUND
  The Thompson grading system is commonly used to classify the severity of degenerative lumbar discs on magnetic resonance imaging (MRI). Inherent differences in the morphological and physiological characteristics of cervical discs have hindered development of precise classification systems. Other grading systems have been developed for degenerating cervical discs, but their versatility and feasibility in the clinical setting is suboptimal.
  
  
  METHODS
  MRIs of 46 human cervical discs were de-identified and displayed in PowerPoint format. Each slide depicted a single disc with a normal (grade 0) disc displayed in the top right corner for reference. The presentation was given to 25 physicians comprising attending spine surgeons, spine fellows, orthopaedic residents, and two attending musculoskeletal radiologists. The grading system included Grade 0 (normal height compared to C2-3, mid cleft still visible), grade 1 (dark disc, normal height), grade 2 (collapsed disc, few osteophytes), and grade 3 (collapsed disc, many osteophytes). The ease of use of the system was gauged in the participants and the interobserver reliability was calculated.
  
  
  RESULTS
  The intraclass correlation coefficient for interobserver reliability was 0.87, and 0.94 for intraobserver reliability, indicating excellent reliability. Ninety-five percent and 85 percent of the clinicians judged the grading system to be clinically feasible and useful in daily practice, respectively.
  
  
  CONCLUSIONS
  The grading system is easy to use, has excellent reliability, and can be used for precise and consistent clinician communication.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Lloydine J
authors.initials: LJ
authors.lastname: Jacobs
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Antonia F
authors.initials: AF
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: James D
authors.initials: JD
authors.lastname: Kang
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Joon Y
authors.initials: JY
authors.lastname: Lee
keywords: Cervical spine; Degenerative disc disease; Grading or classification system; Magnetic resonance imaging