Common paediatric fractures and growth-plate injury — formative SAQs

SAQ 1 (10 marks) — The seven-year-old with a swollen elbow and a pale hand

Stem: A seven-year-old boy falls off the monkey bars onto an outstretched hand and presents with a swollen, S-deformed right elbow held guarded. His hand is pale and the radial pulse is absent. The lateral elbow radiograph shows a fully displaced extension-type supracondylar humerus fracture. Outline your assessment, classification, and immediate management. [5] [10]

Model answer

Assessment and the threatened hand (3 marks). This child has a fully displaced extension-type supracondylar humerus fracture complicated by vascular compromise — a pale, pulseless hand. The immediate priority is the limb. I give analgesia, splint the arm in a position of safety, and perform and document a full neurovascular examination before any manipulation: radial, ulnar and brachial pulses and capillary refill, and the radial, median and ulnar nerves, plus the anterior interosseous nerve tested with the OK sign, because the anterior interosseous nerve is the commonest nerve injured in the extension supracondylar. The pale, pulseless hand is a vascular emergency. [5] [10]

Classification (2 marks). I classify by Gartland: type I undisplaced, type II displaced with the posterior cortex intact, type III fully displaced with no cortical contact. This is a Gartland III — fully displaced — and it is the subtype that is unstable and that goes to theatre. The anterior humeral line on the lateral radiograph passes anterior to the capitellum, confirming the extension displacement. [5]

Immediate management (5 marks). The fracture is reduced promptly to relieve the stretch on the neurovascular bundle, because restoring alignment often restores the pulse. A Gartland III is then managed by emergency closed reduction and percutaneous pinning. I use two or three divergent lateral-entry pins rather than crossed pins, because the meta-analysis of randomised trials and the Skaggs pin-placement study showed that lateral-entry pins reduce the iatrogenic ulnar nerve injury rate while maintaining fixation — a medial pin risks transfixing the ulnar nerve at the medial epicondyle. After reduction and pinning I reassess the hand: a pink, perfused, pulseless hand may be observed because the collaterals are intact, but a hand that remains white and poorly perfused is taken back for exploration of the brachial artery. I admit the child, elevate the arm, and monitor for compartment syndrome, which can develop even after a successful reduction and which is released if the forearm becomes tense and painful on passive finger extension. [4] [5]

SAQ 2 (10 marks) — The eight-year-old with a torus fracture of the distal radius

Stem: An eight-year-old girl falls onto her outstretched hand and has mild dorsal distal-radius tenderness but is still using the hand. The lateral wrist radiograph shows a small buckling of the dorsal distal radius cortex with no break through to the opposite cortex. Discuss the classification, the management, and the evidence that supports it. [3]

Model answer

Classification (3 marks). This is a buckle or torus fracture of the distal radius — a compression failure in which the cortex crumples or kinks without breaking through to the opposite side. It is one of the pliable-bone patterns unique to children, distinct from the greenstick (one cortex broken, one intact) and the complete transverse fracture (both cortices disrupted). The buckle is inherently stable: it does not displace, because the cortex on the opposite side is intact and the periosteum is continuous, and that stability is what determines its benign course and its management. [3]

Management (3 marks). Because the torus fracture is stable and never displaces, it does not need rigid immobilisation. I manage it with a soft bandage or a removable splint for around three weeks, with adequate analgesia and a clear safety-netting advice to return if the pain worsens or persists. A rigid below-elbow cast is not required, and over-immobilising the stable buckle is the common over-treatment that the contemporary evidence has corrected. [3]

The evidence (4 marks). The FORCE equivalence randomised trial — a multicentre study of four-to-fifteen-year-olds with distal radius torus fractures — showed that offering a soft bandage was no worse than rigid immobilisation for pain and function at three days, and the children given a bandage had better function and less pain than those given a cast. A systematic review and meta-analysis confirmed that bandage or splint was as effective as a cast. The teaching that follows is that the buckle fracture is managed lightly, reviewed only if pain persists, and that the force of the evidence is in favour of the least restrictive immobilisation. [3]