Pediatric Transient Synovitis of Hip

  • Etiology: idiopathic inflammatory process leading to fluid in hip joint
  • Radiograph: widened hip joint space, not sensitive or specific for hip effusion, helpful in excluding other pathologies of hip pain
  • US: hip effusion
  • DDX: septic hip is indistinguishable from transient synovitis on US
  • Clinical: most common cause of limp and acute pain in children < 10 years old

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.