Transient synovitis: is there a need to aspirate hip joint effusions?

There is debate as to the optimal management of children with hip joint effusions especially regarding the decision to aspirate. The objective of this study was to determine whether there is a need to aspirate hip joint effusions detected on ultrasound in patients with clinical transient synovitis (TS) and to identify the natural history of these effusions. Twenty-five children with proven hip joint effusions were followed up sequentially by clinical and radiological examination until symptom free. The mean age was 6 years with equal right/left distribution. No child underwent hip aspiration and no cases of sepsis were missed. The median size of hip effusion detected on ultrasound at presentation was 9 mm. At 7 days 60% (15/25) of patients had a normal clinical examination with no detectable effusion on ultrasound. At 14 days 16% (4/25) had an effusion detectable on ultrasound but they were all pain and limp free and their effusions were reducing in size. These results support the known benign nature of TS and that it will settle with conservative treatment.