Your next patient is 2 year old Sadie. She has presented to the ED with a very guilty looking father. He says that he was “watching the kids” whilst his wife went to the store. They were playing in the back yard when thing got a little crazy and he attempted a complete 360 vertical sling whilst holding her by the wrists. She landed safely but has been refusing to use her right arm ever since… that was 4 hours ago now. He was hoping it would all get better before his wife returned from the shops… but no luck. So here he is now at triage with a quiet little princess – who is cradling her right arm in a semi-flexed position by her side.
After calling his wife to check her date-of-birth and allergy history she is clerked into the ED….
[Seriously: is this an Aussie male thing – or is it a global phenomenon that most fathers cannot recall basic details for their children? Let me know. I assume the Swedish Dads are up to the task..]
Diagnosis: too easy – a classic pulled elbow, “nursemaid’s elbow” or radial head subluxation – as it is formally known.
The mechanism of injury is usually a sudden traction on the extended forearm. See paper below for interesting review of actual activities involved.
Image from imgarcade.com
The radius is distracted from its position in the elbow where it articulates with the capitellum. A band of the annular ligament that usually encircles the radial head slips in to the groove. thus a blockage to extension and rotation is in place – the kid will not extend the elbow.
How does this occur? Well found this huge [3000 kids] retrospective case series on pulled elbows that managed to break down the mechanism by physical activity and by “carer gender” – i.e. was it the Mum or the Dad who was doing something with the arm when it popped. Have a read of – No Longer a “Nursemaid’s” Elbow: Mechanisms, Caregivers, and Prevention by Rudloe et al in Paed Emerg Care 2012
The bottom line: Female carers tended to injury the kid in a more passive mechanism – eg. kid tripped or pulled away; where male carers were more likely to be doing wizzy-dizzies, wrestling, flinging kids about… no surprises really! Note that there are a a fair percentage with an “uncertain” mechanism – so you may not get the classic traction story.
OK – so after taking the history and having a look at the kid you are happy with the clinical diagnosis. So how do you fix it?
If you are new to Paeds ED or GP then this is one of those moments – you remember seeing this or maybe even doing it during your training – but how does it go again?
So there are basically 3 ways to “reduce” a pulled elbow:
- Supination / flexion (SF)
- Hyperpronation (HP)
- the “2 in A Room” technique – Wiggle it, just a little bit [No evidence for this one!]
I was always trained (and have trained others) to use the flexion / supination technique – which works OK. But how does it stack up to an RCT examination? So what is your “go to” technique when you want to perform the magic and cure the kid with your bare hands?
Well there are a number of small trials in recent years that have looked at this – and they have remarkably consistent findings. Here are the success rates
Amer Journ of EM, July 2013. Gunaydin et al: SF = 68%, HP = 95%
Nigerian Journ Clin Pract 2014, Guzel Comparison of hyperpronation and supination-flexion techniques in children SF = 84 % HP = 95 %
Cochrane review in 2012 by Krul et al looked at 4 small trials – they found a significantly better success rate with HP over SF with a RR of 0.45 [0.28 – 0.73 ]
So on review – hyperpronation seems to be the best first option. Significantly higher first attempt success and to meet seems easier to visualise.
Here is a video from the great Dr Larry Mellick – he has heaps of Youtube videos of common ED procedures. My main tip is to place your thumb over the radial head as you pronate / supinate – this allows you to feel the click as it pops back over the ligament – it is satisfying and usually means a successful outcome.
And in most of these studies where the first attempt failed (either HP or SF) then the other technique succeeded on nearly every occasion. But…
Have you ever had that kid with a dead set, certain Pulled elbow who you go through the motions,pull, reduce and walk away – come back 5 minutes later and they are still not using the limb? I have – it is one of those moments. Hmm… am I missing something? What do I do next?
I reckon there are a few common scenarios where the routine “reduction” might fail.
- If the elbow has been “out” for a prolonged time (e.g.. overnight) – I find it takes longer for the kid to get over the apprehension of pain and start using it freely.
- If the diagnosis is wrong. Could be a fracture: radial head, supracondylar.. though these usually present with a fall, trauma history
- You are being too gentle with your technique
So what do you do if you have tried, given it a proper wrench, tried the “other” technique and waited a good while for the kid to regain their confidence. And still no luck?
You could do an Xray… but that is ridiculous! Have you ever tried to interpret a 2 year old’s elbow Xray – it is really just a series of blobs floating in invisible cartilage! There is a great guide to “Elbow Ossification in kids” on Radiopaedia here. At age 2 [the mean age for pulled elbows] only the capitellum is even visible – the rest are ghosts!
Xray may reveal signs of a supracondylar or epicondylar fracture – e.g.. “fat pad sign” of effusion / haemarthrosis – which will make you feel really bad about the recent tweaking and twisting manoeuvres – though this is no reason to Xray every kid with a pulled arm.
So what about ultrasound. Can we answer any of these questions with the bedside machine?
Interesting small study out of Korea – by Lee, Sohn and Oh in Clin & Exper EM in 2014 – showed that the finding of a displaced annular ligament on US was 100% specific for “pulled elbow” but only modestly sensitive 64.9%. So US would be useful to “rule in” a pulled elbow – which would be very helpful in ruling out other diagnoses.
If you are worried about a possible occult supracondylar fracture – then ultrasound can be useful here also. Eckert et al in Europ Journ Trauma Emerg Surg April 2014 looked at the diagnosis of SCFs in kids using US – it was pretty good. Sensitivity of 100% in a small study using plain Xray read by Radiologist as the standard.
So in summary:
- Pulled elbow is a clinical diagnosis [the history may not always be classical]
- Hyperpronation should be the first line manoeuvre
- Supination / flexion should be plan B
- IF not winning after a few tries – then we need to consider imaging
- Ultrasound is useful for ruling in a pulled elbow [using a displaced annual log as the sign of choice]
- Ultrasound is useful for ruling in supracondylar fractures
- X-rays can be very confusing – but if you need to then go on….
See you in Chicago