title: Detection of active disease in juvenile idiopathic arthritis: sensitivity and specificity of the physical examination vs ultrasound.
abstract: OBJECTIVE
  To determine sensitivity and specificity of the physical examination (PE) for identifying synovitis in the knee and ankle joints of children with juvenile idiopathic arthritis (JIA), and to identify cases in which ultrasound (US) screening augments the PE.
  
  
  METHODS
  Nineteen patients with JIA were referred for US. Both knees and ankles were examined using US with and without power Doppler. Active arthritis on PE was defined as (1) non-bony swelling or (2) limitation of motion with either pain on motion or tenderness to palpation. Active arthritis on US was defined as synovial hyperplasia, effusion, or increased vascularity on power Doppler scan.
  
  
  RESULTS
  There was agreement between US and PE in 75% of cases. PE was 64% sensitive and 86% specific for identifying active arthritis. PE was 100% specific if (1) the patient was positive for both PE criteria or (2) if arthritis was present on PE in the knees. When the PE was negative and the US was positive, 21.4% developed active disease on PE within 6 months. In cases where the PE was positive and US was negative, the joint involved was most often the ankle and frequently the subtalar joint.
  
  
  CONCLUSIONS
  PE is neither highly sensitive nor specific for identifying active synovitis when compared to US, and screening with US can identify subclinical disease. In joints with both non-bony swelling and limitation of motion with pain on motion or tenderness, and in the knee joint, little additional information is gained by US. This has implications for classification and treatment of JIA.
authors.affiliation: Department of Pediatrics, Division of Pediatric Rheumatology, Children's Hospital at Montefiore, Bronx, NY 10467, USA.
authors.forename: Ginger L
authors.initials: GL
authors.lastname: Janow
authors.forename: Vikash
authors.initials: V
authors.lastname: Panghaal
authors.forename: Angela
authors.initials: A
authors.lastname: Trinh
authors.forename: David
authors.initials: D
authors.lastname: Badger
authors.forename: Terry L
authors.initials: TL
authors.lastname: Levin
authors.forename: Norman T
authors.initials: NT
authors.lastname: Ilowite
mesh_terms: D000293:Adolescent; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000473:pathology; D001171:Arthritis, Juvenile / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D010808:Physical Examination / Q000592:standards*; D012680:Sensitivity and Specificity; D014463:Ultrasonography