A 4-year-old child presents refusing to move their right arm after a sudden pull by the mother. The arm is held in slight flexion with pronation and adduction and there is tenderness over the radial head.
1. What is the most likely diagnosis?
This child has suffered a ‘pulled elbow’. Infants and young children are particularly prone to subluxation of the head of the radius at the proximal radioulnar joint. This is often referred to as a ‘pulled elbow’ as it typically occurs following a quick pull on the child’s arm.
The arm is typically held motionless at the child’s side with them refusing to move it. The arm is often held in slight flexion with pronation and adduction and there is often tenderness over the radial head on palpation.
2. What is the pathogenesis of this condition?
The sudden pulling of the arm tears the attachment of the annular ligament, where it is loosely attached to the neck of the radius. The radial head then moves distally, partially out of the torn annular ligament. The proximal part of the ligament may become trapped between the head of the radius and the capitellum of the humerus.
3. How is this condition treated?
Reduction of a subluxed radial head is easily performed in the Emergency Department and complications are rare. There are two typical manoeuvres, supination and pronation. Using the supination technique, the forearm is twisted or rotated outwards, this can also be followed by flexion of the elbow. Using the pronation technique, the forearm is twisted or rotated inwards. Both methods are generally safe and effective, although bruising can occur, and they can be painful.
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