Case 19 A febrile boy with a limp
Fawad, a 4-year-old boy visiting the UK from Pakistan, presents to the ED at 3pm on a Sunday with a fever and limping. The FY2 doctor in ED takes a history from mum, who speaks little English. This reveals that Fawad had a minor fall in the park 5 days ago and developed a fever of 39°C 3 days ago. He has been complaining of pain in his right leg for 48 hours, and is now refusing to weight bear. The FY2 doctor bleeps the Paediatric ST1 doctor, as she is unable to examine Fawad, who screams whenever she touches him.
What would you do now?
The ST1 takes a limited history also without an interpreter. He tries to examine the child, but Fawad is crying and fighting him off. He attempts to take blood but is unsuccessful and stops as Fawad is becoming very distressed. At 5.45pm the ST1 contacts the Paediatric registrar, who is busy on the neonatal unit, and advises oral analgesia and hip X-rays. The ST1 also calls the orthopaedic ST2, who says he will review the child with the X-ray results.
What is your differential diagnosis?
The Paediatric ST1 is concerned about the possibility of a septic arthritis, but feels that the X-rays are normal and is reassured now that Fawad has settled down following analgesia. Examination of Fawad is normal and there is no deformity, swelling or erythema of the right leg. However, Fawad still cries when the right hip is examined and he refuses to walk. The ST1 doctor now feels that the diagnosis is more likely to be a transient synovitis. He is aware that Fawad has been in the ED for nearly 4 hours and that the mother is keen to go home to her other children. On discussion with his registrar he decides to discharge the child with ibuprofen prior to the orthopaedic review, and to see him on the day unit in 2 days.
Do you agree with this management plan?
Fawad re-presents to the ED on Tuesday morning, accompanied by his mother and an English relative, concerned that he is still febrile and in more pain. They are referred directly to the paediatric registrar who is worried about the right hip. She takes blood for culture, FBC, CRP and ESR, and contacts the orthopaedic registrar, who advises holding off antibiotics until their review. The orthopaedic team see him on the ward with blood results that show a WCC of 18.3 × 109/L (normal 4–12 × 109/L) with 15.7 × 109/L neutrophils (normal 1.5–6.0 × 109/L), CRP of 176 mg/L (normal<6 mg/L) and ESR of 92 mm/h (normal <10 mm/h). They arrange a hip ultrasound that afternoon which demonstrates a significant joint effusion. In view of the risk of a septic arthritis they proceed to an arthrotomy under general anaesthetic later that evening and remove significant amounts of infected material from the joint. Microscopy of the joint fluid shows gram positive bacteria, and grows Staphylococcus aureus after 24 hours.
Fawad’s temperatures settle after 48 hours but he continues to complain of pain and requires analgesia, a prolonged course of intravenous antibiotics and physiotherapy. After discharge a MRI scan reveals changes consistent with avascular necrosis of the hip and he requires further surgery; despite this his limp persists. Fawad’s family complain, stating that if the infection had been diagnosed at the first presentation his subsequent problems would have been avoided.
Expert opinion
The presentation of fever with a limp in a child (3–10 years) is very common and is usually due to transient synovitis. However, septic arthritis must be considered, particularly in children with high fevers and refusal to weight bear. Joint infections are notoriously difficult to diagnose and plain radiographs are usually normal, but necessary to exclude traumatic injury, a diagnosis of Perthe’s disease or a slipped upper femoral epiphysis in an older child. Kocher’s algorithm includes 4 criteria to distinguish septic arthritis from transient synovitis: refusal to weight-bear; fever >38.5°C; ESR >40 mm/h; and WCC >12.0 × 109/L. The probability of a joint infection rises from < 0.2% with none of these features, to 99% if all four are present. In this case the failure of the paediatric ST1 to do blood tests, compounded by the lack of senior paediatric or orthopaedic review at presentation and the delay in review until 2 days later, led to a delay in diagnosis and treatment. Late treatment, five or more days after onset of symptoms, is associated with a high incidence of sequelae such as avascular necrosis or damage to the growth plate, whereas cases treated promptly have an excellent outcome.
Legal comment
This case will prove indefensible and should be settled as soon as possible. There was a clear failure to diagnose the problem and earlier intervention would probably have prevented the damage to the hip.
The language barrier meant that it was difficult for the ST1 to obtain a good history. But attempts should have been made to find an interpreter. A judge is unlikely to excuse this failing.
