Overview Snapshot A 5-year-old child presents to the pediatrician with severe left elbow pain. His mother explains that the pain started after she suddenly pulled him away from the curb. The child's arm is held in slight flexion and pronation. Introduction Clinical definition subluxation (partial dislocation) of the radial head relative to the radiocapitellar joint also known as Nursemaid elbow Epidemiology incidence second most common serious elbow injury in children after supracondylar fractures demographics most common in children between 2-5 years of age Etiology traumatic injury commonly due to excess longitudinal traction on a child's arm e.g., a parent pulling vigorously on child's arm Pathoanatomy normal anatomy of the elbow 3 joints radiocapitellar joint radial head articulates with the humeral capitellum ulnohumeral joint trochlear notch of the ulna articulates with the humeral trochlea proximal radioulnar joint radial head articulates with the radial notch of the ulna 2 ligamentous stabilizers lateral collateral ligament (LCL) complex contains the annular ligament, a proximal radioulnar joint stabilizer medial collateral ligament (MCL) complex mechanism of injury longitudinal traction applied to an extended arm leads to subluxation (partial dislocation) of the radial head inferiorly interposition of the annular ligament into the radiocapitellar joint Symptoms lateral elbow pain child will hold the elbow in slight flexion and the forearm pronated Physical exam pain and tenderness localized to the lateral aspect of the elbow Imaging Radiographs indication not routinely indicated given a strong clinical history and exam unless other bony conditions (e.g., elbow fractures) need to be ruled out findings normal radiographs in patients with radial head subluxation Treatment Conservative closed reduction of the radial head indication nearly all cases will resolve with closed reduction technique supination of the forearm with the elbow in slight flexion Differential Supracondylar humerus fracture distinguishing factors typically caused by fall on outstretched hand instead of excess traction will demonstrate evidence of fracture on radiography Lateral condylar fracture distinguishing factors typically caused by fall on outstretched hand instead of excess traction will demonstrate evidence of fracture on radiography Recurrence occurs in 5-39% of cases but generally ceases after 5 years of age