MRI diagnosis of osteochondral lesions in the talus and the dynamic follow up analysis after osteochondral transplantation

Abstract

To investigate MRI findings of osteochondral lesions in the talus;to evaluate the value of MRI in diagnosing and determining the stage of osteochondral lesions;to analyze the follow up clinical value of MRI in osteochondral transplantation of autologous bone. A total of 79 patients from February 2013 to March 2015 had been retrospectively analyzed. All the patients were treated in our hospital. The ankle arthroscopy results were used as the reference standard, and the accuracy of MRI in diagnosis and Hepple staging had been investigated. Fifteen patients with cartilage transplantation of autologous bone were followed up with MRI examination and evaluation of cartilage repair score(MOCART) after one year. The values of MRI in the postoperative follow up were analyzed. Hepple staging of 79 patients was shown as follows:7 cases of stage I, 12 cases of stage II, 24 cases of stage III, 16 cases of stage IV, and 20 cases of stage V. Ankle arthroscopy grading of 59 patients in this group(in addition of 20 cases of stage V):2 cases of grade A, 2 cases of grade B, 4 cases of grade C, 14 cases of grade D, 22 cases of grade E, and 15 cases of grade F. The accuracy rate of MRI in determining Hepple V was set at 100%, and Hepple stage I corresponds to the arthroscopic A, B, C stage, stage II corresponds to D stage, stage III corresponds to E stage, stage IV corresponds to F stage. The accuracy rate of MRI in determining Hepple stage I to IV was 87.5%, 85.7%, 95.4% and 93.3% respectively. After cartilage transplantation of autologous bone, MRI of 15 patients showed cartilage surface in transplanted area was smooth, bone healed well, and the surrounding edema disappeared. The MOCART was 30 to 80 scores with an average score 59.0±15.6;9 cases of these 15 patients were(9/15, 60%) higher than 60 score. MRI plays a significant role in clinical diagnosis and staging of the talus osteochondral injury. As a method of long term follow up after cartilage transplantation, MRI can well evaluate the rapair of the postoperative osteochondral injury.