title: Quantitative magnetic resonance imaging (MRI) evaluation of cartilage repair after microfracture (MF) treatment for adult unstable osteochondritis dissecans (OCD) in the ankle: correlations with clinical outcome.
abstract: OBJECTIVE
  To quantitatively evaluate cartilage repair after microfracture (MF) for ankle osteochondritis dissecans (OCD) using MRI and analyse correlations between MRI and clinical outcome.
  
  
  METHODS
  Forty-eight patients were recruited and underwent MR imaging, including 3D-DESS, T2-mapping and T2-STIR sequences, and completed American Orthopaedic Foot and Ankle Society (AOFAS) scoring. Thickness index, T2 index of repair tissue (RT) and volume of subchondral bone marrow oedema (BME) were calculated. Subjects were divided into two groups: group A (3-12 months post-op), and group B (12-24 months post-op). Student's t test was used to compare the MRI and AOFAS score between two groups and Pearson's correlation coefficient to analyse correlations between them.
  
  
  RESULTS
  Thickness index and AOFAS score of group B were higher than group A (P < 0.001, P < 0.001). T2 index and BME of group B were lower than group A (P < 0.001, P = 0.012). Thickness index, T2 index and BME were all correlated with AOFAS score (r = 0.416, r = -0.475, r = -0.353), but BME was correlated with neither thickness index nor T2 index.
  
  
  CONCLUSIONS
  Significant improvement from MF can be expected on the basis of the outcomes of quantitative MRI and AOFAS score. MRI was correlated with AOFAS score. BME is insufficient as an independent predictor to evaluate repair quality, but reduction of BME can improve the patient's clinical outcome.
  
  
  CONCLUSIONS
  • Patients with unstable ankle OCD had satisfactory clinical outcome after MF. • Quantitative MRI correlates with clinical outcome after MF for ankle OCD. • The reduction of subchondral BME will improve the patient's clinical outcome. • Quantitative MRI can monitor the process of cartilage repair over time.
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, 12 Wulumuqizhong Road, Shanghai, 200040, China.
authors.forename: Hongyue
authors.initials: H
authors.lastname: Tao
authors.forename: Xiliang
authors.initials: X
authors.lastname: Shang
authors.forename: Rong
authors.initials: R
authors.lastname: Lu
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Hua
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Feng
authors.forename: Shuang
authors.initials: S
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D064386:Ankle Fractures / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D000843:Ankle Joint / Q000473:pathology* / Q000601:surgery; D001182:Arthroscopy; D016025:Bone Transplantation / Q000379:methods; D002358:Cartilage, Articular / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005592:Fracture Fixation / Q000379:methods; D005598:Fractures, Spontaneous / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010008:Osteochondritis Dissecans / Q000175:diagnosis*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014182:Transplantation, Autologous; D016896:Treatment Outcome; D055815:Young Adult