Pediatric Transient Synovitis of Hip

Etiology: inflammatory process leading to fluid in hip joint
Radiograph: widened hip joint space, not sensitive for hip effusion
US: hip effusion
DDX: septic hip, indistinguishable from transient synovitis on US

Radiology Cases of Transient Synovitis of Hip

US of transient synovitis of the hip — Sagittal US of the hips shows a large anechoic fluid collection in the anterior recess of the right femur, which is not present in the left hip. This right hip effusion, when tapped under ultrasound guidance, returned clear fluid.

Ultrasound of transient synovitis of the hip — Sagittal US of the hips shows a large anechoic fluid collection in the anterior recess of the left femur, which is not present in the right hip. This left hip effusion, when tapped under ultrasound guidance, returned clear fluid.