Accuracy of sonography in transient synovitis

The presence of acute transient synovitis (TS, irritable hip) often warrants hospital admission not only to exclude underlying sepsis but also to aspirate when the intraarticular pressure might induce ischemia in the femoral head. Diagnostic doubt may affect this admission. We evaluated 68 patients in a prospective study comparing sonography with diagnostic aspiration and clinical examination. Sonography proved to be relatively accurate (81%) but was inferior to careful clinical evaluation in diagnosing hip effusions. Sonography may be helpful if diagnostic doubt exists. Aspiration under sonographic control will improve this accuracy.