title: Usefulness of high resolution US in the evaluation of effusion in osteoarthritic first carpometacarpal joint.
abstract: OBJECTIVE
  The aim of this study is to provide a reproducible and quantitative sonographic method for evaluation of effusion in the first carpometacarpal joint in osteoarthritis.
  
  
  METHODS
  High resolution sonography of the carpometacarpal joint of the thumb was carried out in 20 normal joints and in 57 joints from patients with osteoarthritis. A 10 MHz transducer was used.
  
  
  RESULTS
  The articular cavity appeared as a hypoechoic triangular area. In normal joints the mean values obtained by measuring the distance between the apex and the base of the triangle was 2.89 mm (SD 0.22). In osteoarthritic joints it was significantly increased (p<0.001). The authors assert that the presence of effusion is very likely if the value is >3.33 mm (mean+2 SD).
  
  
  CONCLUSIONS
  Sonography provides useful, reproducible, and quantitative data for detection of effusion within the first carpometacarpal joint.
authors.affiliation: Department of Medical Therapy, University La Sapienza, Rome, Italy. Baiardini@uniroma1.it
authors.forename: A
authors.initials: A
authors.lastname: Iagnocco
authors.forename: G
authors.initials: G
authors.lastname: Coari
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008662:Metacarpophalangeal Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000473:pathology; D015203:Reproducibility of Results; D013582:Synovial Fluid / Q000000981:diagnostic imaging*; D013933:Thumb / Q000000981:diagnostic imaging*; D014463:Ultrasonography