Demonstration of osteochondritis dissecans of the talus by coronal computed tomographic arthrography.

Ten cases of osteochondritis dissecans of the talus are reviewed. Coronal computed tomographic arthrography identified the precise location in each case and consistently revealed the extent of the lesion to be greater than that apparent on the plain radiographs. The talar cartilage over the lesion was shown to be thinned in four cases, deficient in two, and fissuring of the cartilage was demonstrated in four. Subarticular cysts were identified in all but two cases and contrast medium was shown to enter the cysts in two cases indicating a communication with the ankle joint. The aetiology and relevance of these findings to treatment are discussed.