Conditions Affecting The Elbow Flashcards
What is the most common mechanism for a supracondylar fracture of the humerus?
Falling from a moderate height onto an outstretched hand with a hyperextended elbow
E.g. falling from monkeybars
In what group are supracondylar fractures most common?
Children <10 years
Peak at age 5-7 years
Where is the fracture line, usually, in a supracondylar fracture?
Usually extra-articulate
The distal fragment is usually displaced posteriorly
What are the 3 main complications of a supracondylar fracture?
1) malunion resulting in cubitus varys
2) damage to median nerve (most common), radial or ulnar nerve
3) ischaemic contracture- damage to brachial artery causing ischemia to muscles in anterior compartment of forearm
What is Volkmann’s ischaemic contracture?
- A form of ischaemic contracture from a supracondylar fracture - brachial artery damage causes ischemia of muscles of anterior compartment of forearm
- Results in oedema which further impedes arterial flow leading to infarction if untreated.
- Repair of dead muscle tissue replaced by fibrotic tissue casusing contracture
Describe the appearance of the arm in Volkmann’s contracture
- Wrist is flexed
- Fingers extended at MCPJ
- fingers flexed at interphalangeal joints
- Forearm pronated
- Elbow flexed
How does dislocation of the elbow usually occur?
FOOSH with elbow partially flexed
In which direction do 90% of elbow dislocations occur?
Posteriorly
The distal end of humerus is driven through joint capsule anterioraly
The ulnar collateral ligament is usually torn
How do anterior elbow dislocations occur?
Result of a direct blow to the posterior aspect of a flexed elbow
What is pulled elbow (nursemaid’s elbow)?
Subluxation if the radial head
Classically caused by longitudinal traction applied to the arm e,g. Tugging child’s arm/ swinging arm during play
Why does pulled elbow occur more commonly when the arm is pronated?
In pronation the annular ligament is more relaxed so is easier for subluxation to occur vs. In supination when the annular ligament is taught
Why does pulled elbow become less common as we age?
As the annular ligament strengthens with age
What is the most common type of elbow fracture?
Radial head and neck fracture
How do radial head and neck fractures usually occur?
FOOSH
What is the sail sign seen on x-rays of a radial head or neck fracture?
An area in the x-ray that indicates effusion is present, usually due to haemarthrosis
It is caused by displacement of the anterior fat pad
What is lateral elbow tendinopathy otherwise known as?
Tennis elbow
How does tennis elbow present?
Tendinopathy of the common extensor tendon at the lateral epicondyle gives pain over the lateral epicondyle during extension of the wrist
What is medial elbow tendinopathy otherwise known as?
Golfer’s elbow
What is olecronon bursitis?
Inflammation of the olecronon bursa located between the skin and the olecronon process of the ulna
Related to repeated minor trauma
How would you treat olecronon bursitis?
Compressible bandaging +/- aspiration
What are rheumatoid nodules?
Nodules on the elbow of patients with RA
Develops in those who tend to be smokers or have more aggressive joint disease
What is gouty tophi?
Nodules masses of monosodium Urate crystals deposited in the soft tissues (Gout arises from defective purine metabolism leading to increased uric acid)
What is cubital tunnel syndrome?
Ulnar nerve compression as it passes through the cubital tunnel (posteriolateral to the medial epicondyle)
What does compression of the nerve in cubital tunnel lead to?
- Paraesthesia in the cutaneous territory of the ulnar nerve (medial side of hand)
- Weakness of muscles supplied by ulnar nerve
