Pediatric Septic Arthritis of Hip

  • Etiology: Infection leading to pus in hip joint
  • Imaging Radiograph:
    — Not sensitive or specific for hip effusion but helpful in excluding other pathologies of hip pain
    — See widened hip joint space or bulging joint capsule or thickening of ilioischial line
  • Imaging US:
    — Sensitive to detection of hip effusion
    — If diagnosis is in question compare to contralateral side
  • DDX: Transient synovitis of hip is indistinguishable from septic arthritis of hip on US
  • Complications: Avascular necrosis of hip
  • Treatment: Surgical and antibiotics
  • Clinical:

Radiology Cases of Septic Arthritis of Hip

Radiograph of a septic hip
AP radiograph of the pelvis shows symmetrical ossification of the femoral epiphyses and normal acetabulae bilaterally. The right femoral epiphysis was felt to be displaced laterally in comparison to the left. A hip ultrasound showed a right hip joint effusion, which when tapped under ultrasound guidance returned pus.
Radiograph and ultrasound of septic arthritis of the hip
AP radiograph of the pelvis was unremarkable. 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 green pus.