I was working peds last night and an 8-year-old male came in with elbow pain after falling on an outstretched hand while playing football. Another player fell on his elbow at the same time. He had an obvious deformity and his elbow film is classic for an eponym fracture:
This is a Monteggia fracture-dislocation. It involves a fracture of the proximal ulna and dislocation of the radial head.
Giovanni Monteggia (1814) originally described this fracture pattern. It is usually associated with a direct blow or a hyperpronation, extension mechanism. In this radiograph the radial head dislocation is obvious, however sometimes it can be subtle and missed. Always draw a line through the radial head and make sure it intersects the capitellum on both the AP and lateral views (radiocapitellar line). Here is an example of a normal radiocapitellar line:
Author: Russell Jones, MD