title: Comparison of arthroscopic and magnetic resonance imaging findings in osteochondral lesions of the talus.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) is widely used for diagnosing osteochondral lesions in the talus. The purpose of this study was to directly compare the MRI with the arthroscopic findings.
  
  
  METHODS
  MR images of 42 ankles were retrospectively reviewed during a period of 67 months. The osteochondral lesions were evaluated by both MRI (0, normal; 1, subchondral trabecular compression and marrow edema; 2A, subchondral cyst; 2B incomplete separation fragment; 3, unattached, nondisplaced fragment with synovial fluid surrounding it; 4, displaced fragment) and arthroscopy (A, smooth and intact, but soft and ballottable cartilage; B, rough surfaces; C, fibrillations or fissures; D, flap present or bone exposed; E, loose, undisplaced fragment; F, displaced fragment). Arthroscopic grade A was considered to be equivalent to MR grade 1, B and C to MR grade 2A, D to 2B, E to 3, and F to 4.
  
  
  RESULTS
  Of the 44 lesions in 42 ankles, 29 lesions marked the same grade on both MRI and arthroscopy (65.9%). Nine lesions were upgraded on arthroscopy (20.5%), and six were downgraded (13.6%). MR grade 3 lesions showed the best correlation (83.3%) and MR grade 1 and 2B lesions showed the worst (50.0 and 55.6 %). Arthroscopic grade A and F showed good correlation (80 and 100%). Grade C and E showed poor (25.0%) and intermediate correlation (66.7%), respectively.
  
  
  CONCLUSIONS
  The MRI grading of osteochondral lesions in the talus was useful and showed a fairly good correlation with arthroscopic classification.
authors.affiliation: Department of Radiology, Armed Forces Capital Hospital, Gyeonggi, Republic of Korea.
authors.forename: Sooho
authors.initials: S
authors.lastname: Bae
authors.forename: Hyeon Kyeong
authors.initials: HK
authors.lastname: Lee
authors.forename: Kyunghee
authors.initials: K
authors.lastname: Lee
authors.forename: Sanghyeok
authors.initials: S
authors.lastname: Lim
authors.forename: Nae-Jung
authors.initials: NJ
authors.lastname: Rim
authors.forename: Jin-Su
authors.initials: JS
authors.lastname: Kim
authors.forename: Jaeho
authors.initials: J
authors.lastname: Cho
mesh_terms: D000328:Adult; D001182:Arthroscopy; D002356:Cartilage / Q000293:injuries / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013628:Talus / Q000293:injuries / Q000473:pathology*; D055815:Young Adult