title: An ultrasound score for knee osteoarthritis: a cross-sectional validation study.
abstract: OBJECTIVE
  To develop standardized musculoskeletal ultrasound (MUS) procedures and scoring for detecting knee osteoarthritis (OA) and test the MUS score's ability to discern various degrees of knee OA, in comparison with plain radiography and the 'Knee injury and Osteoarthritis Outcome Score' (KOOS) domains as comparators.
  
  
  METHODS
  A cross-sectional study of MUS examinations in 45 patients with knee OA. Validity, reliability, and reproducibility were evaluated.
  
  
  RESULTS
  MUS examination for knee OA consists of five separate domains assessing (1) predominantly morphological changes in the medial compartment, (2) predominantly inflammation in the medial compartment, (3) predominantly morphological changes in the lateral compartment, (4) predominantly inflammation in the lateral compartment, and (5) effusion. MUS scores displayed substantial reliability and reproducibility, with interclass correlations coefficients ranging from 0.75 to 0.97 for the five domains. Construct validity was confirmed with statistically significant correlation coefficients (0.47-0.81, P < 0.01).
  
  
  CONCLUSIONS
  The MUS score suggested in this study was reliable and valid in detecting knee OA. In comparison with standing radiographs of the knees, the score detected all aspects of knee OA with relevant precision.
authors.affiliation: The Parker Institute, Department of Rheumatology, Copenhagen University Hospitals, Bispebjerg and Frederiksberg, Copenhagen, Denmark. Electronic address: doktorbirgit@dadlnet.dk.
authors.forename: B F
authors.initials: BF
authors.lastname: Riecke
authors.affiliation: The Parker Institute, Department of Rheumatology, Copenhagen University Hospitals, Bispebjerg and Frederiksberg, Copenhagen, Denmark; Institute of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark. Electronic address: Robin.Daniel.Kjersgaard.Christensen@regionh.dk.
authors.forename: R
authors.initials: R
authors.lastname: Christensen
authors.affiliation: The Parker Institute, Department of Rheumatology, Copenhagen University Hospitals, Bispebjerg and Frederiksberg, Copenhagen, Denmark. Electronic address: soeren.tobias.torp-pedersen.01@regionh.dk.
authors.forename: S
authors.initials: S
authors.lastname: Torp-Pedersen
authors.affiliation: The Parker Institute, Department of Rheumatology, Copenhagen University Hospitals, Bispebjerg and Frederiksberg, Copenhagen, Denmark; Department of Radiology, Copenhagen University Hospitals, Bispebjerg and Frederiksberg, Copenhagen, Denmark. Electronic address: Mikael.boesen@dadlnet.dk.
authors.forename: M
authors.initials: M
authors.lastname: Boesen
authors.affiliation: The Parker Institute, Department of Rheumatology, Copenhagen University Hospitals, Bispebjerg and Frederiksberg, Copenhagen, Denmark. Electronic address: Gudbergsen@dadlnet.dk.
authors.forename: H
authors.initials: H
authors.lastname: Gudbergsen
authors.affiliation: The Parker Institute, Department of Rheumatology, Copenhagen University Hospitals, Bispebjerg and Frederiksberg, Copenhagen, Denmark. Electronic address: henning.bliddal@regionh.dk.
authors.forename: H
authors.initials: H
authors.lastname: Bliddal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006984:Hypertrophy; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging*; D008875:Middle Aged; D009929:Organ Size; D020370:Osteoarthritis, Knee / Q000150:complications / Q000000981:diagnostic imaging*; D054850:Osteophyte / Q000000981:diagnostic imaging* / Q000209:etiology; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013583:Synovial Membrane / Q000000981:diagnostic imaging* / Q000473:pathology; D014463:Ultrasonography
keywords: Clinical outcome; KOOS; Kellgren–Lawrence score; Knee osteoarthritis; Musculoskeletal ultrasound