The case

An otherwise healthy toddler presents with his right arm held gently flexed at his side. He fell earlier in the afternoon but didn’t cry. About 30 minutes after the fall parents began noticing that he was holding the affected arm at his side. He won’t use that arm, supports it with the left hand and does not appear to be in obvious pain. His limb is neurovascularly intact. You attempt a nursemaid’s elbow reduction using the hyperpronation maneuver – he cries, you walk away. Ten minutes later he is still not using the limb. You attempt nursemaid’s reduction using the supination/flexion maneuver, wait another ten minutes. He is still not using the limb. Both parents and you want to get an X-Ray. You do and it shows the following.

The diagnosis

This child has a fracture of the radial head. This is the one fracture that I’ve seen very closely mimic a nursemaid’s elbow. The keys to suspecting a nursemaid’s are history, lack of asymmetric swelling and age. This kid has at least two of the three – and nursemaid’s can happen with mild falls. However In this case there was no satisfying “pop” or feedback of a successful reduction. And, he still refused to use the limb.

The X-Ray shows a blunting or flattening of the normally smooth contour of the radial head. You can see this on the image below.

Discussion

If you think it is a nursemaid’s elbow, and there is no asymmetry/swelling then go ahead and attempt reduction. if you fail to reduce then reconsider both your technique, and also the accuracy of your presumed diagnosis. Ultimately, obtain an X-Ray in children whom both reduction maneuvers – when properly performed – fail to result in tactile and/or audible feedback and result in rapid resolution of symptoms.

These are hard to diagnose, since the radial head doesn’t completely ossify until approximately age four. If you only obtained an elbow X-Ray make sure you can see the entire ulna so that you are not missing a Monteggia (equivalent) fracture.  More displaced fractures (not like this one) can be hard to reduce and make require operative fixation.

Reading List

Nursemaid’s elbow: Is one reduction maneuver superior?

Wheeless’ Online: Radial head Fracture

Macias et al. A comparison of supination/flexion to hyperpronation in the reduction of radial head subluxations. Pediatrics. 1998 Jul;102(1):e10.