Patient selection: child with a painful hip
Criteria for transient synovitis of the hip:
(1) absence of bone changes on imaging studies indicative of Perthe's disease, osteomyelitis and trauma/fracture
(2) ultrasound and clinical findings
(2a) no effusion
(2b) effusion without clinical or laboratory findings suggestive of septic arthritis
(2c) effusion with clinical or laboratory findings suggestive of septic arthritis and with an aspirate negative for pus and bacteria
(3) uneventful recovery on conservative therapy
Clinical and laboratory findings suggestive of septic arthritis as described in previous section:
(1) rectal temperature >= 38°C
(2) erythrocyte sedimentation rate (ESR) >= 20 mm in first hour
(3) C-reactive protein >= 20 mg/L
