Child health for AMC MCQ

A 3 year old refuses to weight bear on one leg, holds the hip flexed and externally rotated, and cries when it is moved. He has a fever of 38.8C and looks unwell. His inflammatory markers are markedly raised. He will not let anyone touch the hip. He had been well until two days ago. What is the most likely diagnosis?

1. Transient synovitis A sore hip in a well child after a virus. Only diagnosed once infection is ruled out. Here, the picture of a hot, held, immobile hip with fever and refusal to weight bear points elsewhere.
2. Non-accidental injury An injury where the story does not add up. That does not match the picture of a hot, held, immobile hip with fever and refusal to weight bear.
3. Slipped upper femoral epiphysis Hip or knee pain with the leg turned outward, in a teenager. It does not fit the picture of a hot, held, immobile hip with fever and refusal to weight bear.
4. Septic arthritis correct Correct. A hot, stiff hip that will not move, with fever, refusing to stand, and raised infection markers, is septic arthritis.
5. Perthes disease The blood supply to the top of the thigh bone dying off, around four to eight years old. But the picture of a hot, held, immobile hip with fever and refusal to weight bear does not point to it.

The point: Septic arthritis is the emergency that must never be missed in a limping child. Fever, refusing to stand on the leg, a joint held still and stiff, and raised blood markers of infection all point to it. A tool called the Kocher criteria helps work out the risk. The joint fluid is drawn off and washed out right away, with antibiotics given, because an infected joint gets destroyed within days. It must always be ruled out before calling a sore hip transient synovitis, which is only diagnosed once infection is ruled out in a well child with no fever.

Source: Royal Children's Hospital Melbourne — Clinical practice guideline: the limping child Royal Children's Hospital Melbourne · tier 2, specialty society or college

A 3 year old refuses to weight bear on one leg, holds the hip flexed and externally rotated, and cries when it is moved. He has a fever of 38.8C and looks unwell. His inflammatory markers are markedly raised. He will not let anyone touch the hip. He had been well until two days ago. What is the most appropriate initial investigation?

1. Newborn hip examination and ultrasound The Ortolani and Barlow hip tests, plus an ultrasound, check for hip dysplasia. But the picture of a hot, held, immobile hip with fever and refusal to weight bear does not point to it.
2. Assessment matched to the child's age The child's age narrows down the likely cause. That does not match the picture of a hot, held, immobile hip with fever and refusal to weight bear.
3. Joint aspiration where septic arthritis is suspected correct Correct. Fever, a held hip and raised markers mean the hip fluid is drawn off urgently, usually guided by ultrasound, to prove the infection and start the washout.
4. Examination of the hip in a child with knee pain Checks the hip, since knee pain can actually come from there. Here, the picture of a hot, held, immobile hip with fever and refusal to weight bear points elsewhere.
5. Inflammatory markers and blood tests His infection markers are already known to be markedly raised, so repeating blood tests adds nothing; the joint fluid is the test that settles it.

The point: Septic arthritis is the emergency that must never be missed in a limping child. Fever, refusing to stand on the leg, a joint held still and stiff, and raised blood markers of infection all point to it. A tool called the Kocher criteria helps work out the risk. The joint fluid is drawn off and washed out right away, with antibiotics given, because an infected joint gets destroyed within days. It must always be ruled out before calling a sore hip transient synovitis, which is only diagnosed once infection is ruled out in a well child with no fever.

Source: Royal Children's Hospital Melbourne — Clinical practice guideline: the limping child Royal Children's Hospital Melbourne · tier 2, specialty society or college

A 3 year old refuses to weight bear on one leg, holds the hip flexed and externally rotated, and cries when it is moved. He has a fever of 38.8C and looks unwell. His inflammatory markers are markedly raised. He will not let anyone touch the hip. He had been well until two days ago. What is the most appropriate next step in management?

1. Harness or referral for developmental dysplasia A special harness (Pavlik harness) or referral to a specialist. It does not fit the picture of a hot, held, immobile hip with fever and refusal to weight bear.
2. Urgent joint washout and intravenous antibiotics correct Correct. It needs the joint washed out and antibiotics given right away, before the joint is destroyed.
3. Examine the hip in a child with knee pain Always check the hip, since knee pain is often coming from there. Here, the picture of a hot, held, immobile hip with fever and refusal to weight bear points elsewhere.
4. Orthopaedic follow-up with physiotherapy, and surgery if severe Watching, physiotherapy, or surgery, depending on how bad it is. That does not match the picture of a hot, held, immobile hip with fever and refusal to weight bear.
5. Orthopaedic referral for structural hip disease Sends Perthes disease, a slipped growth plate, and hip dysplasia to a bone specialist. But the picture of a hot, held, immobile hip with fever and refusal to weight bear does not point to it.

The point: Septic arthritis is the emergency that must never be missed in a limping child. Fever, refusing to stand on the leg, a joint held still and stiff, and raised blood markers of infection all point to it. A tool called the Kocher criteria helps work out the risk. The joint fluid is drawn off and washed out right away, with antibiotics given, because an infected joint gets destroyed within days. It must always be ruled out before calling a sore hip transient synovitis, which is only diagnosed once infection is ruled out in a well child with no fever.

Source: Royal Children's Hospital Melbourne — Clinical practice guideline: the limping child Royal Children's Hospital Melbourne · tier 2, specialty society or college