MR imaging of osteochondral lesions of talus

Ten patients with osteochondral lesions of the talus had magnetic resonance (MR) imaging to determine if this modality could accurately characterize the bone lesion and overlying articular cartilage. Eight patients had arthroscopy, five of whom also had arthrotomy. Magnetic resonance detected abnormal cartilage in all eight patients and disruption of cartilage in four of five, proven at surgery. One patient had disrupted cartilage at surgery not diagnosed by MR. Four patients had excision of the osteochondral fragment and curettage of the talar defect and in these patients MR accurately characterized the bony lesion. Three patients had conservative surgical procedures (drilling) and the extent of the bony lesion could not be determined at surgery. Magnetic resonance can accurately characterize the osteocartilaginous components of talus lesions and even though it should not replace plain radiography for diagnosis, it is ideally suited for evaluation of the articular cartilage and has proven to be useful in planning surgical procedures.