With thanks to Dr Jess Spedding for the continuation of her minor injuries series….
Minor Injuries Series, part 2: The Elbow Xray and Supracondylar fracture:
The elbow xray typically strikes fear into the heart of clinicians as there are so many centres of ossification which appear at different stages of a
child’s development and can quite easily be mistaken for bony injury. Remember that the smooth rounded appearance of a centre of ossification does not often mimic the typically sharp edges of a new fracture fragment, but even saying this, distinction can be very difficult. If you have the CRITOL (or CRITOE) acronym in your mind, it will help you to interpret the xray with a sensible approach. The image below highlights each of the six ossification centres with the typical age of the child when each centre appears:
Note: Lateral / External epicondyle are interchangeable terms, giving either CRITOL or CRITOE
Work through in order the centres of ossification – each may appear at slightly different ages in different children, but the sequence in which they
appear should always be C,R,I,T,O,L. For example in a 6 year old you would not expect the lateral condyle to have appeared yet, so if there is a bony fragment at that site, it is suggestive of a fracture.
The supracondylar fracture (of the distal humerus) is the most common upper limb fracture in young school age children. It presents almost always as
a FOOSH (fall on the outstretched hand). They are likely to be in a lot of pain, and may need strong analgesia and immobilisation (with a splint or
sling) before assessment is possible. (A good example of a strong, rapid acting, well tolerated analgesic that can be used in the Emergency Department is intranasal diamorhpine, which is made up with saline into a small volume of fluid and then given as nose drops with a syringe.)
You may well see bruising and swelling around the elbow, with tenderness around the distal humerus, but remember to check the whole limb including
clavicle (and the whole of their body if the mechanism of injury could have caused other serious injuries!)
The elbow contains numerous important neurovascular structures – your assessment must document presence of radial pulse, capillary refill time in
fingertips and function of ulnar, median and radial nerves (not possible formally in younger children, so watch to see if they will hold a toy or parents hand
and be suspicious if the xray shows a displaced fracture). Any concerns about neurovascular compromise require the fracture to be urgently reduced, either by the Emergency Department team or referral to Orthopaedics. This initial reduction is to relieve mechanical pressure of displaced bony fragments on the
neurovascular structures and will not provide the stability required for neatly aligned healing, so a trip to theatre for fixation will happen soon after.
A common classification system for supracondylar fractures is the Gartland classification. In this there are three categories of supracondylar fractures based on their radiological appearance on the lateral elbow view:
1: undisplaced – recognised as clinical suspicion plus xray evidence of fluid in the elbow joint elbow (as demonstrated by a raised anterior fat pad or
the presence of a posterior fat pad) and possibly loss of anterior humeral line (normal is when line along anterior humerus intersects middle third of
2. visible fracture which is hinging on the posterior edge
3. totally displaced
Type 1 can usually be managed conservatively with an above elbow cast and sling, whilst 2 and 3 require operative fixation.
All should be followed up by Orthopaedics in fracture clinic – typical progress is evidence of union at 4 weeks, and then the patient is encouraged to
gradually do away with the sling, to allow mobilisation without too much discomfort.
A rare but debilitating late complication of supracondylar fractures is Volkmann’s ischaemic contracture (when the brachial artery is damaged and months later the patient develops clawing of the thumb and fingers and forearm wasting).