Disorders Of The Elbow Flashcards
What can be seen on an x-ray of a radial head fracture?
Fat pad
What is the most common paediatric elbow fracture?
Supracondylar fracture of distal humerus
Mechanism of supracondylar fracture of distal humerus
Fall onto outstretched hand
Main complications of supracondylar fracture of distal humerus
- Malunion
- Damage to median (most common), radial or ulnar nerve
- Volkmann’s Ischaemic contracture
- Damage to brachial artery
Explain how supracondylar fracture of distal humerus can casue Volkmann’s ischaemic contracture
- if fracture causes damage to brachial artery, ischaemia of anterior muscles will occur
- this causes oedema + compartment pressure increase»_space; compartment syndrome
- due to lack of O2, muscles undergo infarction
- in repair, muscle tissues are replaced by scar tissue through fibrosis
- myofibroblasts in fibrosis contracts
What nerve is most commonly damaged in supracondylar fractures of distal humerus?
Median nerve
Assessment of supracondylar fracture of distal humerus
- Examine + document media nerve - ‘ok sign’ or ask to make a fist - last three fingers with flex only
- Examine and document brachial artery - radial pulse + capillary refill time
What is the test to determine median nerve damage?
Ok sign
If patient cant form ok sign»_space; possible median nerve injury
Ask to make a fist
Can’t flex 2nd + 3rd digits
What are the tests to determine brachial artery damage?
Radial pulse
Capillary refill time
Management of supracondylar fracture of distal humerus
1- Closed reduction with percutaneous pinning
2- Hold in position with plaster
- if this doesn’t restore nerve function > surgery
Close - without making a cut
Reduce - put back in position
What is reduction of a fracture
Putting bone back into position
What group of people is a pulled elbow most common in?
2-5 years old
Weak annular ligament
What happens in a pulled elbow?
Radial head subluxes from annular ligament
Presentation of a subluxed radial head
Pain
Child not using elbow
Mechanism of subluxation of radial head
Longitudinal traction with extended arm + forearm pronated
e.g. parent swinging child around by arms
Treatment of subluxation of radial head
Reverse the forces - flex elbow
- supinate forearm
Why does a pulled elbow happen more commonly in pronation than supinate
Annular ligament is relaxed in pronation
Easier for subluxation to occur
What is nursemaid’s elbow?
Pulled elbow - subluxation of radial head
Mechanism of posterior elbow dislocation
Fall onto outstretched arm
What dislocation is most common in the elbow?
Posterior
Mechanism of anterior elbow dislocation
Direct blow to posterior aspect of flexed elbow
What other injury is often associated with anterior elbow dislocations?
Fractures of olecranon
Due to force needed to dislocate joint anteriorly
What is a complex dislocation?
Fracture associated with dislocation
What is a simple dislocation?
No associated fractures
