title: The Lichtman classification for Kienböck's disease: an assessment of reliability.
abstract: OBJECTIVE
  The correct identification of Lichtman stage 3A and 3B Kienböck's disease is crucial for treatment purposes. The present study evaluates the reliability of the Lichtman classification, with specific attention to differentiating stage 3A and 3B.
  
  
  METHODS
  Four reviewers evaluated wrist radiographs from 39 patients with Kienböck's disease. Radiographs were graded according to the traditional Lichtman classification, a modification of the Lichtman classification using a radioscaphoid angle of 60 degrees to subdivide stage 3, and 8 other radiographic measures.
  
  
  RESULTS
  The interobserver reliability of the Lichtman classification was substantial (kappa coefficient 0.63), but Stage 3A was less reliably identified (kappa 0.38). The new modification of the Lichtman classification increased both the overall (kappa 0.81) and the stage 3A (kappa 0.75) interobserver reliability.
  
  
  CONCLUSIONS
  The use of the radioscaphoid angle increases the interobserver reliability of the Lichtman classification. This should allow a better understanding of the clinically important distinction between stage 3A and 3B disease.
authors.affiliation: Department of Orthopaedic Surgery, Barnes-Jewish Hospital at Washington University, One Barnes Hospital Plaza, Suite 11300, St Louis, MO 63110, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Goldfarb
authors.forename: James
authors.initials: J
authors.lastname: Hsu
authors.forename: Richard H
authors.initials: RH
authors.lastname: Gelberman
authors.forename: Martin I
authors.initials: MI
authors.lastname: Boyer
mesh_terms: D006801:Humans; D012667:Lunate Bone / Q000000981:diagnostic imaging; D015588:Observer Variation; D010020:Osteonecrosis / Q000145:classification* / Q000000981:diagnostic imaging*; D011859:Radiography; D021361:Scaphoid Bone / Q000000981:diagnostic imaging; D014955:Wrist Joint / Q000000981:diagnostic imaging