Annie is a 2-year-old with 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.
Could she have a pulled elbow?
The anatomy of the elbow joint
The medial and lateral collateral ligaments 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 off 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.
How do pulled elbows occur?
It’s 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.
How do children with pulled elbows present?
Children most commonly present with not using their arm. On assessment, the arm often hangs 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.
They have pain on pronation and supination.
There are two main techniques to reduce a pulled elbow.
The hyper-pronation method
The first is hyper-pronation. Rest your thumb over the radial head. This isn’t to apply pressure, it’s just so you can feel the click when it reduces. Then hyper-pronate the arm.
The supination method
The second technique is supination-flexion. Again rest your thumb 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 hyper-pronation technique had a better success rate at first attempt reduction than the supination technique. The Number Needed to Treat (NNT) is 6.
And as Simon Craig nicely illustrated – the Yin and Yang of pulled elbows:
What happens if it doesn’t go clunk?
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 it fails on the first attempt, try again using the other technique. If the child is still not using the arm, get an x-ray.
Sometimes you may feel like the reduction was successful, but they are not using the arm normally. This may be because the annular ligament was torn when the elbow was pulled, and this 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, consider these red flags.
Age outside of peak prevalence – The peak incidence occurs between 1 and 3 years of age. Only 3.2% occur in children older than four 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.
Thanks to Simon Craig, Amanda Stock and Joanne Pleban for their post-publication contribution.