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, Amanda Stock and Joanne Pleban for their post-publication contribution.
The medial and lateral collateral ligaments each hold the humerus and ulna together (one on either side).
The annular ligament holds 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 falls down while holding the parent’s hand and the parent tries to stop them from 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 the 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 than the supination technique (NNT 6).
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 the first attempt. A first attempt successful reduction was more likely in patients presenting within 2 hours of the injury. After two years 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.
But are you sure it’s a pulled elbow?
Pleban, J., Stock, A. and Hopper, S., 2021. Another pulled elbow! Beware the mimic!. Journal of Paediatrics and Child Health.
This recent paper from Pleban, Stock. and Hopper from Melbourne’s Royal Children’s Hospital looks at two cases that could have been mistaken for a pulled elbow. Whilst Coxsackie-induced acute flaccid paralysis and osteomyelitis of the olecranon are uncommon, they point out some red flags for us to consider.
Age outside of peak prevalence – The peak incidence occurs between 1 and 3 years of age. Only 3.2% occur in children older than 4 years.
Unclear history or atypical mechanism – Maybe more of an amber flag than a red one but if the history doesn’t fit, or is unclear, you might have to rethink your diagnosis.
Swelling of upper limb – Given that a pulled elbow is a slip from the annular ligament there should be no arm swelling. Granted, most toddlers have pudgy arms, but look at both sides and compare.
Resting pain or tenderness – The vast majority of pulled elbows are not painful
Absent or reduced power – Discomfort may stop a child from pronating or supinating but there should be no loss of power unless something else is going on.
No return of function – Make sure you provide good return precautions. Just in case.
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.