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The Elbow
I am going to concentrate on Supracondylar fractures, as these are often the most difficulat to diagnose.
The Supracondylar fracture is often difficult to diagnose either clinically or radiologically. Technically the xrays aren't always brilliant (small children in a lot of pain unable to move = harassed radiographer. The elbow accounts for 11% of all fractures in children and 15% of all arm fractures. The supracondylar fracture is the most single common elbow region fracture (44%). A true supracondylar is usually a transverse metaphyseal fracture of which approximately 50% are greenstick with minimal displacement. Usually the displacement of the distal fragment is posterior. Anterior displacement is extremely rare (1%).
It is the commonest elbow region injury and the peak age is 3 - 8 years. It is very rare before 3 years and much more commoner in children than adults. Approximately 60.8% of fractures involve the left hand side.The patient usually presents with the elbow flexed / extended to any angle between 90 and 180 degrees, depending on the degree of the posterior displacement of the fragment. In severe injury it presents as a swollen, painful deformity which is clinically similar to elbow dislocation.
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A Normal Elbow
Check the anterior humeral line
Look for anterior and posterior fat pads
Look for the figure of eight at the distal humerus in the lateral xray
Check for effusions and a complete bony cortical line
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Salter Harris II fracture
The supracondylar fracture is sometimes difficult to diagnose both clinically and radiographically. If clinical examination is positive but xrays are negative, then there should be a suspicion of an occult fracture. Studies have shown that undiagnosed or conservatively treated supracondylar fractures are prone to neurological and varus and valgus deformities.
The supracondylar fracture is probably the most important paediatric arm injury because of the risk to brachial artery, median or ulnar nerves as the altered anatomy causes pressure to be exerted on the arteries or nerves. Where there is appreciable displacment of the fracture, the brachial artery may be affected by the proximal fragment. In the majority of cases this is no more than kinking of the vessel, but occasionally structural damage to the wall may occur, with the risk of Volkmann's ischaemic contracture. This can have permanent affects if not treated immediately. The longer any part of the body is without adequate blood supply the higher the chance of necrosis of bone and soft tisuue.
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Monteggia fracture
Note the highly obvious dislocated radial head. Remember though when you see a fracture, particularly one like this that in the 'bony ring' of the forearm an isolated fracture is very rare. There is usually another fracture or dislocation.
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Yet another Monteggia fracture
Differential Diagnoses:
Pulled Elbow
This condition is due to the radial head stretching the orbicular (annular) ligament and slipping out from under its cover. It occurs in children in the 2 - 6 year group, and is normally caused by a parent suddenly pulling on a child's arm
Dislocated Elbow:
Dislocation fo the elbow is common inchildren and generally results from a fall on an outstretched hand. It can be confused with a supracondylar fracture. The two can be distinguished clinically by searching for the equilateral triangle formed by the olecranon and epicondyles. This is undisturbed in supracondylar fractures, but is distorted in elbow dislocations.
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Olecranon fracture
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The obvious supracondylar is not usually a problem to diagnose or treat. However the subtle supracondylar can present in a variety of different ways. The age of the child usually precludes a good verbal history and makes examination difficult. It is very important to remember that this fracture may not be obvious radiographically except for the appearance of the posterior fat pad sign. If this is positive then it should be assumed that there is an occult fracture. In a study
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radial head fracture
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Supracondylar Fracture
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Supracondylar fracture
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This lateral was repeated and the Supracondylar was then obvious
Often an inadequate lateral xray may not fully demonstrate a subtle supracondylar fracture |
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Yet another Supracondylar fracture
Note the loss of the 'figure of eight' on the lateral xray, at the distal part of the humerus. This may indicate a Supracondylar fracture
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What is wrong here ?
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Ossification Centres are very important
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Ossification centres
Remember CRITOL
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