Inflicted fractures and other non-accidental musculoskeletal injury — OSCE

Candidate information (2 minutes reading, 12 minutes station)

You are the general paediatric registrar in the emergency department. Maya, aged six months and not yet mobile, has a spiral femur fracture with an inconsistent history and a delay in presentation; the skeletal survey shows a classic metaphyseal lesion and a posterior rib fracture. Read the presentation, then conduct the assessment and explain the plan to the family. The examiner will role-play the senior parent. [1] [10]

Candidate tasks

1. Recognise the high-specificity pattern and explain, without accusation, why the combination of a spiral femur, a classic metaphyseal lesion and a posterior rib fracture in a pre-mobile infant requires further investigation. [1] [7]
2. Outline the imaging plan, naming the complete skeletal survey, the follow-up survey at about two weeks, and the CT head and retinal examination to exclude abusive head trauma. [4] [14]
3. Address the differentials honestly, including rickets and osteogenesis imperfecta, without reflexively invoking or dismissing them. [8]
4. Convert to safeguarding, confirm a safe disposition, and address the infant sibling at home. [14]

Marking anchors

Distinction (PASS)

• Names the classic metaphyseal lesion, the posterior rib fracture and the spiral femur in a pre-mobile infant as a high-specificity pattern, and defends the principle that specificity outranks sensitivity and no fracture is pathognomonic. [1] [10]
• Describes the complete skeletal survey and the mandatory follow-up survey at two weeks, citing that occult rib, CML and extremity fractures mature into visibility, and adds CT head and retinal examination for the infant. [4] [14]
• Addresses the rickets and osteogenesis-imperfecta differentials on evidence, citing that rachitic change is absent in fatal AHT with CMLs, without reflexively invoking or dismissing them. [8]
• Converts to safeguarding, confirms a safe disposition, arranges a survey for the infant sibling, and engages the family honestly and without accusation while naming a clear owner and follow-up. [14]

Borderline

• Recognises the concern but treats the femur and defers the skeletal survey or follow-up to "outpatient review," or invokes rickets reflexively without investigation, or addresses the index child but forgets the infant sibling. [4]

Fail

• Accepts the inconsistent "roll off the sofa" history as adequate for a spiral femur in a pre-mobile infant, fails to obtain a skeletal survey or follow-up, interrogates or coaches the family, or discharges Maya without a safeguarding referral or a safety plan despite the high-specificity pattern. [1] [10]

Examiner prompt sequence

1. Opening (the parent): "She just rolled off the sofa, doctor — children fall all the time, don't they?" — Candidate must weigh the developmental stage against the spiral femur and name the high-specificity pattern. [1] [10]
2. The lesion challenge: "What's a classic metaphyseal lesion, and are you saying I shook her?" — Candidate must explain the shearing mechanism without accusation and cite the finite-element evidence. [7]
3. The differential request: "Couldn't it be rickets, or brittle bones? It runs in our family." — Candidate must address the differentials on evidence, citing the absence of rachitic change in fatal AHT with CMLs. [8]
4. The sibling: "What about her baby brother at home?" — Candidate must arrange assessment and a skeletal survey for the infant sibling and confirm a safe disposition. [14]