[Perthes' disease. Accuracy potentials and the value of sonography].

During a 2-year period 59 patients underwent sonography, 33 of them with confirmed Legg-Perthes disease and 26 in whom clinical examination had given rise to suspicion of this disorder. An intraarticular effusion was found in 53% (n = 26) of the patients and characteristic sonographic findings could be detected in 84% (n = 41). The special examination technique and the diagnostic criteria and their validity and correlation to radiologic abnormalities are discussed.