title: Clinical courses and predictors of outcomes in patients with monoarthritis: a retrospective study of 171 cases.
abstract: OBJECTIVE
  To evaluate the clinical courses and outcomes of patients with monoarthritis and to investigate the predictive factors of clinical outcomes.
  
  
  METHODS
  A retrospective analysis was performed of 171 patients with chronic monoarthritis at a single tertiary hospital between January 2001 and January 2011. Baseline characteristics, radiographic findings and the clinical course were reviewed.
  
  
  RESULTS
  The most commonly involved joints were the knees (24.0%), followed by the wrists (22.8%) and ankles (18.7%). A final diagnosis was established in 74 (43.3%) patients. Thirty-one (18.1%) patients were diagnosed with rheumatoid arthritis (RA), 23 (13.5%) with peripheral spondyloarthritis (SpA), and 19 (11.1%) with Behçet's disease (BD). Among 108 patients who were initially undiagnosed, 85 (78.7%) patients remained with undiagnosed monoarthritis, with relatively shorter symptom durations and requiring less treatment. The initially involved joint was a predictive factor for the final diagnosis: the wrist joint for RA (odds ratio [OR] 11.58, P < 0.001), the ankle joint for SpA (OR 6.19, P < 0.001), and the knee joint for BD (OR 3.43, P = 0.014). Bony erosion at baseline was associated with progression to oligo- or polyarthritis (OR 2.88, P = 0.030) and with radiographic progression.
  
  
  CONCLUSIONS
  In patients presenting with monoarthritis, a final diagnosis was established in less than half of the patients, and a majority of undiagnosed patients showed benign clinical courses. The initially involved joint and the presence of erosion at baseline were predictors of the final diagnosis and of clinical outcomes.
authors: Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors: Hyemin
authors: H
authors: Jeong
authors: Ah Yeong
authors: AY
authors: Kim
authors: Hyun Jung
authors: HJ
authors: Yoon
authors: Eun-Jung
authors: EJ
authors: Park
authors: Jiwon
authors: J
authors: Hwang
authors: Hyungjin
authors: H
authors: Kim
authors: Joong Kyong
authors: JK
authors: Ahn
authors: Jaejoon
authors: J
authors: Lee
authors: Eun-Mi
authors: EM
authors: Koh
authors: Hoon-Suk
authors: HS
authors: Cha
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D001175:Arthrography; D001528:Behcet Syndrome / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007596:Joints / Q000187:drug effects / Q000473:pathology*; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D056910:Republic of Korea; D012189:Retrospective Studies; D012307:Risk Factors; D025242:Spondylarthropathies / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D062606:Tertiary Care Centers; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D018501:Antirheumatic Agents
keywords: Behçet's disease; monoarthritis; predictors; rheumatoid arthritis; spondyloarthritis