title: Ultrasound biomicroscopy for the detection of early osteoarthritis in an animal model.
abstract: OBJECTIVE
  Osteoarthritis (OA) is a common disease, and early diagnosis is essential for preventing further cartilage destruction and decreasing severe complications. Ultrasound biomicroscopy (UBM) is sensitive for detecting minute lesions in tissue because of its higher resolution, but its B-mode characterization of the early stage of OA has not been widely studied. The aim of this study was to determine the usefulness of UBM for detecting the early stage of OA using a rabbit model of early OA.
  
  
  METHODS
  Eighteen adult New Zealand White female rabbits were used in this study, which included 12 rabbits that underwent transections of the left anterior cruciate ligament and six control rabbits. At 2, 4, and 6 weeks after surgery, four experimental rabbits and two control rabbits were euthanized. UBM was performed to evaluate the articular cartilage surfaces of the left knee, using a 55-MHz transducer. All the articular cartilage surfaces were independently assessed in blinded fashion by two radiologists for the severity of OA. The value of UBM, interobserver reliability, and the concordance between UBM and pathologic grades were determined.
  
  
  RESULTS
  For the first radiologist, the sensitivity, specificity, positive predictive value, and negative predictive value of UBM for the diagnosis of OA were 91%, 83%, 89%, and 86%, respectively. For the second radiologist, the sensitivity, specificity, positive predictive value, and negative predictive value of UBM were 93%, 86%, 91%, and 89%, respectively. The concordance between UBM and pathologic grades for both radiologists was high (κ = 0.72 and 0.76), and the interobserver agreement was high (κ = 0.80).
  
  
  CONCLUSIONS
  UBM can be used to evaluate cartilage defects in an animal model, and further study is needed to determine whether this technique can be valuable for detecting early OA in humans.
authors.affiliation: Department of Ultrasound, Chinese People's Liberation Army General Hospital, Beijing, China.
authors.forename: Yuexiang
authors.initials: Y
authors.lastname: Wang
authors.forename: Yizhu
authors.initials: Y
authors.lastname: Guo
authors.forename: Lihai
authors.initials: L
authors.lastname: Zhang
authors.forename: Haijun
authors.initials: H
authors.lastname: Niu
authors.forename: Meng
authors.initials: M
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.forename: Wenbo
authors.initials: W
authors.lastname: Wan
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology; D003877:Dermatitis, Contact; D004195:Disease Models, Animal; D005260:Female; D007719:Knee Joint; D033401:Microscopy, Acoustic; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000473:pathology; D011237:Predictive Value of Tests; D011817:Rabbits