[Nosology of osteochondrosis dissecans of the trochlea of the talus].

The histories of 56 patients with the diagnosis "osteochondrosis dissecans tali" were retrospectively analyzed with regard to etiology, localization, therapy, course, and prognosis. Some of the patients were reexamined. In 33 patients it is highly probable that the osteochondrosis dissecans was not associated with the sequelae of osteochondral fractures. The typical X-ray image is that of a medial, deep osteolysis on the trochlea of the talus, close to the margin, with one or more roundish dissections. There are usually no degenerative or posttraumatic changes. The history and frequent bilateralism tend to rule out trauma as the cause. In the authors' opinion, therefore, the term "osteochondrosis dissecans" should not be used for osteochondral fractures and their sequelae. A number of borderline cases are critically discussed.