Ultrasonography in the diagnosis of transient synovitis of the hip and Legg-Calvé-Perthes disease.

Ultrasonography was used to establish the diagnosis of transient hip synovitis and the onset of Legg-Calvé-Perthes disease. A total of 115 patients presenting with 119 painful hips and the preliminary diagnosis of transient hip synovitis were reviewed. Hip effusion, resulting in capsular distension, was documented accurately with ultrasound. In nine patients, capsular distension persisted longer than 6 weeks and was associated with the onset of Legg-Calvé-Perthes disease.