title: Distribution of primary osteoarthritis in the ulnar aspect of the wrist and the factors that are correlated with ulnar wrist osteoarthritis: a cross-sectional study.
abstract: OBJECTIVE
  The purpose of this cross-sectional study was to identify the distribution of primary osteoarthritis (OA) in the ulnar aspect of the wrist, and analyze the factors correlated with OA at this site.
  
  
  METHODS
  A total of 1,128 cases of skeletally mature Japanese patients were collected over a 3-year period. We analyzed the posteroanterior and lateral wrist radiographs of these patients for the presence of primary OA in the ulnar aspect of the wrist, including the distal radioulnar (DRUJ), radiolunate, ulnolunate, lunotriquetral, triquetrohamate, lunohamate, and lunocapitate joints. All joints were examined for the frequency of primary OA. Multivariate logistic regression was used to investigate the factors correlated with the presence of degenerative arthritis in the ulnar aspect of the wrist joint.
  
  
  RESULTS
  Primary OA of the ulnar wrist was identified in 145 out of 1,128 cases (12.8 %). Degenerative changes were most frequently identified in the DRUJ (12.3 %), followed by the ulnolunate joint (8.1 %). Variations in radial inclination (RI), carpal height ratio (CHR), and ulnar variance (UV) correlated with OA of the ulnar aspect of the wrist, with variations in UV showing the highest correlation.
  
  
  CONCLUSIONS
  Primary OA of the ulnar wrist was most frequent in the DRUJ and second most frequent in the ulnolunate joint. UV correlated most with OA in the ulnar aspect of the wrist.
authors.affiliation: Department of Orthopaedic Surgery, Kokuho Central Hospital, 404-1 Miyako, Tawaramoto, Nara 636-0302, Japan. takeshi.k11@k4.dion.ne.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Katayama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ono
authors.forename: Daisuke
authors.initials: D
authors.lastname: Suzuki
authors.forename: Manabu
authors.initials: M
authors.lastname: Akahane
authors.forename: Shohei
authors.initials: S
authors.lastname: Omokawa
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D002348:Carpal Bones / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015995:Prevalence; D011859:Radiography; D012307:Risk Factors; D013223:Statistics as Topic; D014457:Ulna / Q000000981:diagnostic imaging*; D014955:Wrist Joint / Q000000981:diagnostic imaging*