What is the diagnosis?

Oblique, bayonetting* mid-shaft radial fracture with associated ulnohumeral dislocation

*Instead of using the term “bayonetting,” this fracture could alternatively be described as a mid-shaft radial fracture with anterior and ulnar displacement (of the distal fragment).

Image 3-4: labeled AP view of the forearm and lateral/oblique view of the elbow, author’s own images and annotations. 

• Pearl: While not the case here, certain radial and ulnar shaft fractures with associated injuries have eponyms associated with them:

• A Galeazzi fracture involves the distal one-third of the radial shaft with associated injury to the distal radio-ulnar joint (DRUJ) [1].

• A Monteggia fracture involves the proximal one-third of the ulnar shaft with associated dislocation of the radial head [2].

What is the mechanism of injury?

Posterior elbow dislocations frequently result from axial forces transmitted proximally up the ulna, such as a fall onto an outstretched hand (FOOSH) injury, as was the case with this patient [3].  Radial shaft fractures can result from direct trauma to the forearm or, as with posterior elbow dislocation, from axial forces on the forearm transmitted through the hand [4].

What is the management in the ED?

The posterior elbow dislocation should undergo closed reduction in the ED, likely requiring procedural sedation. In this case, the radius fracture does not change your approach for the elbow reduction as the ulna is still intact and able to be manipulated. There can be an attempt at reducing the radius fracture, though it is unlikely to be successful with this degree of displacement and an intact radius preventing traction. Post-reduction films should be obtained, and the arm should be splinted with a double sugar tong splint [5]. It is okay to splint the radius in persistent displacement.

• Pearl: As in any reduction, begin by exaggerating the injury—in this case, applying axial posterior and downward force to the forearm—to allow the coronoid process and olecranon to pass below the trochlea of the humerus. Then firm inline traction with flexion of the elbow guides the humeral head back into the olecranon fossa. 

• Pearl: For a posterior elbow dislocation, a posterior long-arm splint is typically sufficient. For a concomitant  radius fracture, it is also important to immobilize the joint above and below to limit supination and pronation, necessitating the addition of a sugar tong/double sugar tong splint.

When do you consult Orthopedics?

Most forearm fractures and elbow dislocations can be managed with closed reduction as indicated in the ED with outpatient orthopedics follow-up. In this specific case, if the radius is not reduced, urgent orthopedics follow-up is warranted for potential operative planning. We should consult orthopedics for open fractures and neurovascular compromise. It is also reasonable to consult to facilitate more urgent outpatient evaluation.