#MiniTeach: A Problem With My Funny Bone
"A 69-year-old woman trips over her dog while out walking and falls onto her outstretched hand."
She presents to ED with pain in her elbow. She has no symptom or sign of other significant injury.
1. What would the immediate management be by the Urgent Care Centre triage nurse?
Assess pain score
Analgesia appropriate for pain score according to the analgesic ladder.
Check neurovascular status – look to see if the limb appears warm and pink, feel the radial pulse, ask the patient to wiggle her fingers, check that she can feel you touching her fingers.
Apply a broad arm sling.
2. How do you examine the elbow?
Look – Is the injury closed? Is there any swelling or deformity? Is there bruising?
Feel – Palpate for bony tenderness: distal humerus, medial and lateral epicondyles, radial head, olecranon process, soft tissues. Feel down the forearm.
Move – Check the level of extension and flexion (full extension reduces the likelihood of a fracture). Check pronation and supination – (often limited in radial head fractures).
Neuro – Pain may limit the motor response so be gentle.
i. Check the radial nerve: Can they feel the area over anatomical snuff box? Can they extend their wrist?
ii. Check the ulnar nerve: Can they feel their little finger? Can they abduct their fingers against resistance?
iii. Median nerve: Can they feel their index finger? Can they oppose their thumb against resistance?
Vascular - Does the hand and forearm look pink and do they feel warm? Check the radial and ulnar pulses, If you have any concerns, check capillary refill time (and compare it with the other side).
Always check the joint above and joint below. In reality, a painful injury of the elbow will limit the extent of the examination you can do. (It’s not compassionate to try and get a patient with a significant elbow injury to abduct their shoulder for example). It’s worth checking to see if they’re tender anywhere else in the upper limb however (they may only be complaining about the most painful bit) and take any further examination from there. Don’t forget that the radius and ulna form a closed loop in the forearm and a proximal fracture of one can be accompanied by a distal fracture in the other – this is especially true in children.
3. What does the X-ray show? What systems can be used to aid interpretation of elbow X-rays?
The AP and lateral X-rays of the right shoulder shows a minimally displaced, non-comminuted fracture of radial head, with anterior and posterior fat pad signs (although these are difficult to see without the advantage of image manipulation). Check out the attached PowerPoint to see these images.
People have different systems for examining the elbow. A good approach is ABCDEF: Adequacy, alignment, Bones, Centres for ossification and soft tissues, don’t ever forget the fat pads.
Adequacy: Check that a lateral and AP has been done. The lateral is done at 90 degrees flexion and the AP in full extension. Obviously, injuries make this range of movement difficult, so be mindful of how optimal your films are when reviewing them.
Check the Alignment of the humerus and radius with the capitellum.
On the lateral view a line drawn along the anterior cortex of the distal humerus (anterior humeral line) should intersect the middle third of the capitellum.
On all views a line drawn along the long axis of the radial neck (radiocapitellar line) should intersect the middle of the capitellum.
Bones – as with any other musculo-skeletal imaging, check each of the bones in turn looking carefully for fractures.
Check the Centres for ossification (in children). Children’s elbow films look different to adults as they are developing ossification centres. There are 6 of these and they gradually fuse to give the appearances of the adult X-ray. They are remembered by the acronym ‘CRITOL’ – capitellum, radial head, internal (medial) epicondyle, trochlea, olecranon and lateral epicondyle. Those of us who work with kids need to have a good understanding of these – see the links for further details.
Also don’t forget to check the Soft tissues for swelling and foreign bodies.
Don’t ever forget the FAT PADS!
The elbow has a fat pads posteriorly and anteriorly. The posterior one can sometimes be seen normally. The anterior fat pad shouldn’t be visible. It becomes visible when there’s an effusion in the joint (which after a fracture is commonly blood) pushing it forward. It often looks like a sail in this instance (as it does in our patient). Lack of fat pads doesn’t exclude a fracture but if you seen one, you must assume that your patient has a fracture if they present due to trauma.
The following links give good examples of systems that can be used to interpret elbow x-rays:
4. What is your subsequent management?
Further analgesia as required.
Collar and cuff – initial immobilisation in a collar and cuff for a few days should be followed by active mobilisation. This achieves good results in 85-95% patients and prevents long term stiffness associated with prolonged immobilisation.
Fracture clinic referral.
5. How are these sort of injuries classified?
Radial head fractures are classified according to the Mason Classification:
Type I – minimally displaced fracture, no mechanical block to rotation, intra-articular displacement <2mm
Type II – Displaced fracture >2mm or angulated, possible mechanical block to forearm rotation.
Type III – Comminuted and displaced fracture, mechanical block to rotation.
Type IV – Radial head fracture with elbow dislocation.
6. Which patients need operative management?
Mason type II fractures with mechanical block to movement, Mason type III and IV fractures.