Snapshot A 35-year-old man presents to the emergency room for severe right elbow and forearm pain after sustaining a blunt injury to his right arm. On examination, the affected arm is swollen and tender around his elbow. Radiographs demonstrate a displaced fracture of the proximal ulnar diaphysis and radial head dislocation. Introduction Clinical definition traumatic injury to the elbow and forearm characterized by the presence of two bony injuries diaphyseal fracture of the proximal third of the ulna radial head dislocation Prognosis Unfavorable delayed diagnosis radial head dislocation can be missed on initial radiographs Epidemiology Incidence less common than other types of serious elbow injuries in children (e.g., supracondylar fracture, radial head subluxation, and lateral condylar fracture) Demographics more common in children than adults peak age range 4-10 years of age Etiology Traumatic injury Fall On an OutStretched Hand (FOOSH) direct blow to the ulna Pathoanatomy normal anatomy of the elbow and forearm forearm consists of 2 bones radius ulna elbow consists of 3 joints radiocapitellar joint ulnohumeral joint proximal radioulnar joint fracture mechanics fall on an outstretched hand or traumatic blow leads to proximal ulnar diaphyseal fracture and radial head dislocation annular ligament may become interposed in the radiocapitellar joint, preventing reduction of the dislocated radial head Associated conditions may occur with other traumatic injuries to the elbow and forearm distal radius fracture olecranon fracture radial head fracture coronoid process fracture Presentation Symptoms elbow pain and swelling Physical exam tenderness to palpation along the elbow decreased elbow range of motion due to pain radial head may be palpable if significantly dislocated Imaging Radiographs indication radiographs are indicated if there is any suspicion for fracture finding proximal ulnar shaft fracture with radial head dislocation ulna fracture will be easily visible in most cases radial head dislocation can be missed Differential Galeazzi fracture distinguishing factors radiographs will show radial diaphyseal fracture and distal radioulnar joint dislocation patient generally will have pain localized to the wrist instead of the elbow Supracondylar fracture distinguishing factors radiographs will demonstrate evidence of fracture (e.g., fracture line or enlarged fat pads) along the supracondylar humerus without evidence of radial head dislocation Treatment Conservative closed reduction +/- intramedullary fixation and casting indication used in some fractures in children Operative open reduction and internal fixation (ORIF) indication used in all adult fractures and more severe pediatric fractures Complications Posterior interosseous nerve (PIN) palsy generally, a neuropraxia caused by anterior displacement of the radial head spontaneous recovery is expected