THE VALUE OF MAGNETIC-RESONANCE-IMAGING AS POSTOPERATIVE CONTROL AFTER ARTHROSCOPIC TREATMENT OF OSTEOCHONDRITIS-DISSECANS

The purpose of our study was to evaluate the value of MRI for preopera tive arthroscopical planning in patients with osteochondritis dissecan s. Based on the experience from 136 patients with osteochondritis diss ecans of the knee or the ankle who were arthroscopically operated by r etrograde drilling a follow-up study was carried out with 86 of them b y clinical, radiological and postoperative magnetic resonance imagine (MRI) examinations, The evaluation was made by means of a visual analo gue scale and a score system. The radiological findings were analysed according to the classification of Rodegerdts and Gleissner. The chang es based on the MR images were classified according to our own pathoan atomical classification. The total score showed a significant improvem ent from 63.3 to 79.6 points (knee) and from 50.6 to 70.4 points (ankl e). In 72% of the cases, the findings of the MR images showed a defect ive cartilage surface in the area of the osteochondritis dissecans les ion. An increase of signal in the osteonecrotic area could be seen in 51% of the cases when using a short-time inversion recovery (STIR) ima ge. Especially in patients with postoperative failures, a high percent age of cartilage defects (grade III) could be detected on the MR image s (PS 500/10), Uptake of gadolinium-diethylene triamine tetra-acetic a cid was regarded as a sign for revascularization. Radiographs did not correlate with these changes detected in the MR images. This retrospec tive study of an operated osteonecrosis dissecans by MRI provides more detailed information about eventual revascularization of the osteonec rotic area. With this information a more detailed preoperative planing for further cases should be possible.