Elbow: Elbow dislocation

The word dislocation implies separation of the bones of a joint from each other. Three different bones meet at the elbow joint, the humerus on one side, and the radius+ulna on the other side. In simple elbow dislocations, the connection between the ulna and the radius is usually preserved; both radius and ulna as a unit are separated from the humerus.

Elbow dislocations in children must be differentiated from supracondylar fractures, as the distal part of the humerus can be invisible in xrays.

Case study: a pediatric elbow dislocation

You may or may not be able to see a lateral epicondyle ossification in this child's elbow, but the trochlea is clearly visible. This boy was actually 9+8 at the time of injury.

He fell from 3 feet and presented with a deformed, swollen elbow. The mechanism of injury was hyperextension. When I first received the call from the ER, prior to reviewing the xrays I thought "surely this must be a misinterpreted xray, and surely this is a supracondylar fracture."

Xrays clearly show a dislocation however. No evidence of fracture.

The boy underwent deep sedation with ketamine and I then easily manipulated and reduced his elbow. The radial head was felt to be prominent and tenting the skin; this was guided towards the lateral condyle of the humerus, and with only gentle traction a nice "clunk" was felt. Immediate almost-pain-free flexion-extension, pronation, supination was possible. Xrays were done which confirmed reduction.

The child was then placed in a sling, was told to keep the sling on. He was allowed to bend the arm inside the sling, to pronate, supinate, use the hand and fingers inside the sling.

The child was instructed to move the elbow in flexion, but to not extend (straighten) it fully. He was asked to stay 30 degrees short of full extension for the first 4 weeks. He was kept out of gym and sports, he was asked to always wear the sling in school and outside the home.

Formal physical therapy was not seen as necessary and was not done.

The child progressed well, regained full pain free motion.

Follow up xrays show a normal elbow.

Avulsion fracture of the medial epicondyle is a potential problem with child elbow dislocations. The avulsed medial epicondyle can block reduction of the joint and can cause continued pain and stiffness.

In the xrays above, note the medial epicondyle in its proper place. An avulsed medial epicondyle could be displaced close to the trochlea and it might be confused with the normal ossification center of the trochlea.

Subtle differences between the two exist. The medial epicondyle appears in xrays as a small single bean-shaped opacity, whereas the the medial humeral trochlea ossification has a more granular appearance.

Instances of nerve entrapment in the joint have also been described in the orthopedic literature.

It would be important to notify the physician of any continuing pain, and complaints such as numbness, tingling, burning etc. Presence of any such symptoms might indicate a nerve injury.

This child did very well, and had no complaints. He was allowed to return to gym and activities without restriction at 3 months after this injury.