Nursemaid's elbow and common upper-limb injury — formative SAQs

SAQ 1 (10 marks) — The two-year-old carried in refusing to use the right arm

Stem: A two-year-old girl is carried into the emergency department forty minutes after her father lifted her by the right wrist to swing her over a gutter. She cried briefly and has since refused to use the arm. She is afebrile, alert, and smiling, holding the right arm at her side with the elbow flexed to twenty degrees and the forearm pronated. There is no swelling, no deformity, no warmth, and no point tenderness, but she resists supination. Outline your assessment, your immediate management, and your discharge counselling. [1] [4]

Model answer

Assessment and diagnosis (3 marks). This is the classic presentation of a radial head subluxation (nursemaid's elbow). The decisive features are the classic mechanism — a sudden longitudinal pull on the pronated, extended forearm — and the well child holding the arm flexed and pronated with no swelling, no deformity, and no point tenderness. The diagnosis is clinical, and no radiograph is required in this classic case. The child is otherwise well, which argues against infection, and the absence of swelling and tenderness argues against a fracture. [4]

Immediate management — the reduction (5 marks). The reduction is attempted at the bedside by hyperpronation, the preferred first technique. The examiner holds the elbow with one hand, grasps the wrist with the other, and fully pronates the extended forearm in one smooth, firm, continuous motion, carrying the wrist into hyperpronation. The rationale is the randomised evidence: the Macias 1998 trial showed the first-attempt success of ninety-five per cent for the hyperpronation versus seventy-seven per cent for the supination-flexion, and the Aksel 2025 trial confirmed the lower first-attempt failure rate. The proof of success is the return of the normal arm use within fifteen to thirty minutes. If the child does not use the arm by thirty minutes, the hyperpronation is repeated once, then the supination-flexion (supinate the forearm and fully flex the elbow with a thumb over the radial head) is the cross-over. A radiograph is obtained only if both techniques fail or the history is atypical. [1] [6]

Discharge counselling (2 marks). The family is counselled that the annular ligament slipped over the radial head, that the reduction has restored it, and that the condition is benign. The single most important advice is to avoid longitudinal traction on the arm: lift the child under the axillae, do not swing the child by the arms, and hold the hand rather than the wrist when walking. Roughly a quarter to a third of children recur until the annular ligament matures around age five, and the family may be taught the hyperpronation technique to manage a recurrence at home. No follow-up or imaging is needed if the arm returns to normal use. [4]

SAQ 2 (10 marks) — The atypical guarding arm and the supracondylar vascular emergency

Stem: A six-year-old boy presents after a fall from a trampoline onto an outstretched right hand. His elbow is swollen and held in flexion, and he is in considerable pain. On examination the radial pulse is absent and the hand is pale and cool. Separately, contrast this with the toddler whose arm does not reduce after two adequate attempts with both techniques. Discuss the classification, the vascular emergency, and the management of the displaced supracondylar fracture, and the principle that governs the radiograph in the atypical guarding arm. [2] [7]

Model answer

Classification and the vascular emergency (4 marks). The supracondylar humerus fracture is classified by the Gartland system: type I, undisplaced; type II, displaced with an intact posterior cortex; type III, completely displaced with no cortical contact. This boy with the swollen, deformed elbow and the absent pulse has a Gartland III. The absent radial pulse and the pale, cool hand signify a brachial artery injury — the displaced distal fragment has kinked, entrapped, or torn the artery on the anterior surface — and this is a vascular emergency. The elbow is reduced and stabilised, the hand is re-perfused, and the child is taken to theatre for the closed reduction and the percutaneous pinning, with the vascular surgeon on standby if the pulse does not return. The anterior interosseous nerve is the commonest nerve injured in the extension type, tested by the OK sign and the thumb-index pinch, and the nerve function is documented before and after the reduction. [7]

Management of the displaced supracondylar (3 marks). The Gartland I is managed in a long-arm splint or a cast for three to four weeks. The Gartland II and III are taken to theatre for the closed reduction and the percutaneous pinning, with the lateral-entry pins preferred to the crossed pins because the Skaggs study showed the lower rate of the iatrogenic ulnar nerve injury. The neurovascular status is documented before and after the reduction and the pinning, and the majority of the nerve palsies recover spontaneously over weeks to months. The cubitus varus deformity is the late complication of the malunion, prevented by the accurate reduction. [7]

The principle of the radiograph in the atypical guarding arm (3 marks). The contrast is the toddler whose radial head subluxation does not reduce after two adequate attempts with both the hyperpronation and the supination-flexion techniques. The Macias 2000 study showed that a non-classic history — a fall rather than a pull, or the absence of a clear traction mechanism — raises the relative risk of an underlying fracture, and the safeguard is the radiograph. The point tenderness, the swelling, the deformity, or the bruising all argue for the fracture and the radiograph. In every atypical or unreduced guarding arm, the elbow radiograph is obtained to exclude the missed lateral condyle fracture, the undisplaced supracondylar, and the occult forearm fracture, before any further reduction attempts. [2]