title: Outcome of patients with undifferentiated chronic monoarthritis: retrospective study of 46 cases.
abstract: OBJECTIVE
  To determine the natural history of undifferentiated monoarthritis of more than 3 months' duration and to evaluate the usefulness of classic diagnostic tools for identifying factors associated with outcomes.
  
  
  METHODS
  Retrospective study of 46 patients with undifferentiated monoarthritis of more than 3 months' duration.
  
  
  RESULTS
  Full resolution was the outcome in 50% of cases. Rheumatoid arthritis and spondyloarthropathy were the most common diagnoses in the remaining patients. HLA-B27 status was the only significant predictor of outcome: progression to spondyloarthropathy was significantly more common (P = 0.05) among HLA-B27-positive patients. Mean time to full recovery was significantly shorter than mean time to disease progression (12 vs. 45 months, P = 0.0015). Intraarticular glucocorticoid injections were effective in over 50% of patients. Arthritis relief during the month following the injection was associated with self-limited disease. The role for magnetic resonance imaging in managing patients with undifferentiated monoarthritis remains unclear.
  
  
  CONCLUSIONS
  In patients with undifferentiated monoarthritis, the likelihood of a full recovery is 50%. The only significant predictor of outcome was positive HLA-B27 status, which was associated with progression to spondyloarthropathy.
authors.affiliation: Rheumatology Department, Dupuytren Teaching Hospital, 2, avenue Martin Luther-King, 87042 Limoges cedex, France.
authors.forename: Rachida
authors.initials: R
authors.lastname: Inaoui
authors.forename: Philippe
authors.initials: P
authors.lastname: Bertin
authors.forename: Pierre-Marie
authors.initials: PM
authors.lastname: Preux
authors.forename: Richard
authors.initials: R
authors.lastname: Trèves
mesh_terms: D001168:Arthritis / Q000276:immunology*; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D015796:HLA-B27 Antigen / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D025242:Spondylarthropathies / Q000276:immunology
chemical_list: D015796:HLA-B27 Antigen; D002097:C-Reactive Protein