Paediatricscommon
A 3-year-old girl has refused to walk or stand since waking this morning and screams when her right leg is moved. She had a cold last week. Her temperature is 38.9 °C and she looks unwell. The right hip is held flexed, slightly abducted and externally rotated, and any attempt to move it produces severe pain; the knee and ankle are normal. Results: white cell count 17.5 × 10⁹/L, C-reactive protein 68 mg/L, ESR 52 mm/h. A hip ultrasound shows a moderate right effusion.
Which one of the following is the most appropriate next step?