Explain the Kocher prediction rule to a family with an irritable hip — OSCE

Candidate brief

You have eight minutes to counsel the parents of a five-year-old boy who is suspected to have a septic hip, confirmed by a high Kocher score, a hip ultrasound showing an effusion, and an elevated C-reactive protein. Use a structured, honest, empathic approach that explains the problem in plain language, addresses the parents' fears and the playground theory, and builds a shared plan for the aspiration and the possible operation. [4] [8]

Key teaching and communication objectives

Acknowledge and validate the parents' fear before delivering information, and allow silence. Explain in plain language that the fever, the refusal to walk, and the way the child holds the leg tell us that bacteria may have entered the hip joint, and that the fluid inside the joint can damage the bone if it is not drained quickly. Address the playground fall directly — a minor fall does not cause a fever or a refusal to walk, so the fall is not the cause, though the child may have favoured the leg because of it. [7]

Address the procedure and the plan clearly. Explain that the orthopaedic team will place a small needle under ultrasound to take a sample of the fluid, and that if the fluid shows infection, the child will go to theatre to have the joint washed out under anaesthetic. Reassure them that the anaesthetic keeps the child comfortable and asleep, that the operation is routine for this problem, and that the earlier the washout, the better the outcome for the hip. [4]

Address the reassurance honestly without minimising the urgency. Explain that the blood tests and the ultrasound have pushed the probability of infection high, and that the team is acting quickly precisely because early drainage protects the joint. Offer the hope that the fluid may sometimes be sterile — a reactive inflammation called transient synovitis — but explain that the team cannot take that risk when the score is this high, and the aspiration is the test that tells them. [8]

Close with a shared plan and a clear next step. Name the surgeon who will perform the procedure, give a realistic timeline for the decision and the operation, explain that intravenous antibiotics will start after the sample is taken, and offer the parents the chance to stay with the child until the anaesthetic. Invite questions, confirm understanding using a teach-back, and arrange a follow-up conversation after the procedure. [4] [7]