Annular Ligament Displacement, Radial Head Subluxation: (Nursemaid’s Elbow)

Presentation

A toddler who is between 1 and 4 years of age presents with upper extremity pain and reluctance to use that extremity following a sudden jerk on the arm. Circumstances surrounding the injury may be obvious (such as a parent pulling the child up by the arm to avoid stepping into a puddle, pulling a child back by the arm who is trying to run out into the street, or a child having been swung by forearms during play). On the other hand, the mechanism of injury may be obscure (the untruthful babysitter who reports that the child “just fell down”). The patient and family may not be accurate about localizing the injury and think that the child has injured the shoulder or wrist. The patient is comfortable at rest, splinting the arm limply at the side (pseudoparalysis) with mild flexion at the elbow and pronation of the forearm. There should be no deformity, crepitation, swelling, or discoloration of the arm. There is also no palpable tenderness, except possibly over the radiohumeral joint. However, the child will start to cry with any movement of the elbow, especially attempted supination. The left arm is affected more frequently than the right, as most caregivers are right-handed and hold the child’s left hand.