title: Atraumatic medial collateral ligament oedema in medial compartment knee osteoarthritis.
abstract: OBJECTIVE
  To describe and determine the prevalence of atraumatic medial collateral oedema identified in patients with medial compartment osteoarthritis.
  
  
  METHODS
  Sixty patients, 30 patients with medial compartment knee osteoarthritis (Kellgren and Lawrence grade 2 to 4) and 30 age-matched patients with atraumatic knee pain without osteoarthritis, referred for MR imaging over a 2 year period were included in the study. In each case, severity of osteoarthritis was recorded on radiographs and correlated with the presence or absence of medial collateral ligament oedema at MR imaging.
  
  
  RESULTS
  Medial collateral oedema was identified in 27 of the 30 patients with osteoarthritis, of whom 14 had grade 1 oedema and 13 had grade 2 oedema compared with the presence of medial collateral ligament oedema (grade 1) in only two of the 30 control patients without osteoarthritis ( P<<0.0001).
  
  
  CONCLUSIONS
  Medial collateral oedema is common in patients with osteoarthritis in the absence of trauma. When identified, medial collateral ligament oedema should be considered to be a feature of osteoarthritis and should not be incorrectly attributed to an acute traumatic injury.
authors.affiliation: Department of Radiology, Mater Misericordiae Hospital, Dublin, Ireland.
authors.forename: Diane
authors.initials: D
authors.lastname: Bergin
authors.forename: Ciaran
authors.initials: C
authors.lastname: Keogh
authors.forename: Martin
authors.initials: M
authors.lastname: O'Connell
authors.forename: David
authors.initials: D
authors.lastname: Rowe
authors.forename: Binod
authors.initials: B
authors.lastname: Shah
authors.forename: Adam
authors.initials: A
authors.lastname: Zoga
authors.forename: Patricia
authors.initials: P
authors.lastname: Fitzpatrick
authors.forename: Stephen
authors.initials: S
authors.lastname: Eustace
mesh_terms: D004487:Edema / Q000209:etiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D017888:Medial Collateral Ligament, Knee / Q000473:pathology*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000473:pathology*