Annie is a 2 year old who has a painful arm. Her mum was holding her hand as she walked along the pavement. Annie tripped and Annie’s mum tried to stop the fall. Since then she hasn’t been using the arm as much.
Thanks to Simon Craig for his post-publication contribution.
The medial and lateral collateral ligaments each hold the humerus and ulna together (one on either side).
The annular ligament hold the radius and ulna together.
In a pulled elbow, the annular ligament slips of the head of the radius and can get trapped in between the radius and humerus. This causes restriction of movement and pain on pronation and supination.
If you want to review your anatomy then check out our elbow radiology section.
The mechanism is usually from a pull of the arm e.g. when the child fall down while holding the parent’s hand and the parent tries to stop them falling by pulling the arm.
The child most commonly presents as not using their arm and on assessment has the arm hanging limply by their side. When asked, they may point to distal radius as the point of pain, which can lead us to suspect a buckle fracture. There will be pain on pronation and supination.
There are two main techniques to reduce a pulled elbow.
The first is hyper-pronation. For this technique apply pressure over the radial head, then hyper-pronate the arm.
The second technique is supination-flexion. Again apply pressure over the radial head, supinate the arm, and then flex the elbow (while the arm is still supinated).
A 2017 Cochrane review found low quality evidence that the hyperpronation technique had a better success rate at first attempt reduction that the supination technique (NNT 6).
The child is already mostly extended and pronated already, so it’s just a gentle straighten out (extend) and hyperpronation.
One hand on the radial head just to feel the “click”
— Simon Craig (@DrSimonCraig) August 14, 2018
And as Simon Craig nicely illustrated – the Yin and Yang of pulled elbows:
Sevencan et al (2015) looked at 66 patients presenting with pulled elbows. 57 were successfully reduced on first attempt. A first attempt successful reduction was more likely in patients presenting within 2 hours of the injury. After two year follow up 24% had recurrence (but they will eventually grow out of it).
After a successful reduction, the child should be using the arm normally within 10-15 minutes. If the reduction fails on the first attempt, then try again using the other technique. If the child is still not using the arm, then get an x-ray.
Sometimes you feel like the reduction was successful (you may have felt a click) but the child is not using the arm normally. This may be because the annular ligament was torn when the elbow was pulled and it may take time to heal. In these cases, put the child in a broad arm sling and review them again in a few days.
Annie’s pulled elbow was successfully reduced on the first attempt using the hyper-pronation technique. Five minutes later she was using her arm normally. She was discharged from ED.