Session 8: Conditions Affecting the Elbow Flashcards
Common conditions affect the elbow:
Supracondylar fracture of the distal humerus Dislocated elbow Pulled elbow (nursemaid’s elbow) Radial head and neck fractures OA of elbow Rheumatoid Arthritis Lateral elbow tendinopathy (tennis elbow) Medial elbow tendinopathy (golfer’s elbow) Olecranon bursitis (student’s elbow) Rheumatoid nodules Gouty tophi Cubital tunnel syndrome
What is this?
A supracondylar fracture of the distal humerus.
Mechanism of injury of a supracondylar fracture
Usual age of injury
Usual gender
Symptoms
Usually from falling from a moderate heigh onto an outstretched hand with elbow hyperextended (child fallong off monkey bars e.g.)
Younger than 10 years of age (peak age is 5-7 years)
Males
Pain, deformity and loss of function.
What does a supracondylar fracture look like?
Flexed and distal fragment is displaced and protrudes posteriorly.
Proximal fragment might protrude anteriorly.
Three main complications of supracondylar fractures.
Malunion resulting in cubits varus. Also called gunstock deformity.
Damage to median nerve (most common), radial nerve or ulnar nerve.
Ischaemic contracture
Further explain ischaemic contracture.
Since the brachial artery passes close to the fracture site it can become damaged or occluded. If there are reflex spams of the collateral circulation around the elbow there will be ischaemia of the muscles in the anterior compartment of the forearm.
Results in oedema and a rise in compartment pressure (compartment syndrome). If left untreated muscle bellies will undergo infarction and can die. During repair phase the dead muscle tissue becomes replaced by scar tissue by fibrosis. Fibrotic tissue contracts reuslting in a flexion cotnracture known as Volkmann’s ischaemic contracture.
What does an ischaemic contracture leading to a Volkmann’s ischaemic contracture look like?
The wrist is typicall flexed and fingers are extended at metacarpophalangeal joints and flexed at interphalangeal joints. Forearm is pronated and elbow is flexed.
This is due to the fibrotic tissue contracting.
To minimise risks of these complications. What is done?
Prompt and thorough neurovascular examination. Any compromise to supply of forearm or hand will lead to emergency reduction and fixation of the fracture.
You examine by checking radial pulse, OK sign, paraesthesia and capillary refill.
What is this?
Dislocated elbow. Specifically posterior dislocation.
What type of elbow dislocation is most common?
Posterior dislocation (90%)
Anterior disclocation (10%)
It is called posterior because the distal fragment has displaced. It is named after the displacement of the distal fragment.
Mechanism of injury of posterior dislocation of elbow.
Age
Internal mechanism
FOOSH = fall on outstretched hand with the elbow partially flexed
Most common joint displacement in children (second most common in adults after shoulder)
Distal end of the humerus is driven trough the joint capsule anteriorly. Ulnar collateral ligament is usually torn and maybe also ulnar nerve damage.
Why is it more common to dislocated elbow if it is partially flexed?
Because when it is flexed most of the stability relies on the ligaments.
If it is extended fully most of the stability relies on the bones.
Mechanism of injury of anterior dislocation of elbow.
Associated fractures
Direct blow to the posterior aspect of a flexed elbow.
Fracture of olecranon due to high degree of force needed to dislocate the joint anteriorly.
What does a posterior dislocated elbow look like?
What is nursemaid’s elbow or pulled elbow?
It is also called subluxation of the radial head which is a partial disruption of a joint. Usually subluxation from anular ligament.
Mechanism of injury of subluxation of radial head.
Age
Symptoms
Longitudinal traction applied to arm with forearm pronated. For example grabing an uncooperative child or swinging child by their arms during play.
2-5 years of age.
Reduced movement of elbow and pain of lateral aspect of proximal forearm. Parents usually say that their child doesn’t use their arms.
Why doesn’t subluxation of the radial head usually occur <2 years of age?
Why is it less common as you get older?
Because most children don’t walk yet and there is no need to tug them to be cooperative therefore.
Neglection signs.
Because the annular ligament naturally strenghtens.
Why is subluxation of radial head more common during pronation of forearm?
Because the annular ligament is taut in supination and more relaxed in pronation.
What is this?
Radial head and neck fracture.
Mechanism of injury of radial head and neck fractures.
Age
Symptoms
FOOSH = fall on an outstretched hand when the radial head impacts on the capitellum of the humerus
Most common in adults (most common elbow fracture as well in adults)
Pain in lateral aspect of their proximal forearm and loss of range of movement. Swelling associated with fractures is usually modest in comparison with supracondylar fractures.
What are signs of radial head and neck fractures on an x-ray?
Can be difficult to see.
Fat pad signs also called sail sign which indicates effusion. Displaced fat looks black.
Haemarthrosis which is blood in the joint.
Sail sign is caused by displacement of the anterior fat pad.
Why is OA relatively uncommon in elbow?
Well-matched joint and strong stabilising ligaments. Less weak and tear and stable.
X-ray features of rheumatoid arthritis.
Joint space narrowing
Periarticular osteopenia
Juxta-articular bony erosions
Subluxation and gross deformity
How is RA managed?
Usually medically rather than surgically by disease-modifying medication.
Surgery can be required in severe cases to relieve pain and improve mobility.
In this image you can see erosion of humeroulnar joint with most of the trocheal of the humerus having been destroyed. Sigmoid fossa (trochlear fossa) is enlarged. This patient may be a candidate for total elbow replacement.
What is this?
Olecranon bursitis
What is this?
Rheumatoid nodules
What is this?
Gouty tophi
