Elbow Joint Flashcards
What is the elbow?
The joint connecting the proper arm to the forearm
How is the elbow marked on the upper limb?
By the medial and lateral epicondyles, and the olecranon process
Structurally, what is the elbow classed as?
A synovial joint
Functionally, what is the elbow classed as?
A hinge joint
What does the elbow consist of?
The articulation of the trochlea notch of the ulna and trochlea of the humerus
The articulation of the head of the radius and the capitulum of the humerus
What does the orientation of the bones forming the elbow joint produce?
A hinge type synovial joint
What does the elbow joint allow for?
Extension and flexion of the forearm
What produces extension at the elbow joint?
Triceps brachii and anconeus
What produces flexion at the elbow joint?
Brachialis, biceps brachii, brachioradialis
Do pronation and supination occur at the elbow?
No, they are produced at the nearby radioulnar joints
What does the elbow joint have?
A capsule enclosing the joint
How can the capsule of the elbow joint be described?
Strong and fibrous
What does the joint capsule do in itself?
Strengthens the joint
Where is the joint capsule of the elbow thickened?
Medially and laterally
What is formed when the joint capsule of the elbow thickens medially and laterally?
Collateral ligaments
What is the purpose of the collateral ligaments of the elbow joint?
They stabilise the flexing and extending motion of the arm
Where is the radial collateral ligament found?
On the lateral side of the elbow joint, extending from the lateral epicondyle, and blending with the anular ligament of the radius
What is the anular ligament of the radius?
A ligament from the proximal radioulnar joint
Where does the ulnar collateral ligament originate from?
The medial epicondyle
Where does the ulnar collateral ligament attach to?
The coronoid process and olecranon of the ulna
What do bursae prevent?
Degenerative damage
What are the clinically important bursae of the elbow joint?
Intratendinosus
Subtendinosus
Subcutaneous
Where is the intratendinosus bursae formed?
Within the tendon of the triceps brachii
Where is the subtendinosus bursae found?
Between the olecranon and the tendon of the triceps brachii
What is the purpose of the subtendinosus bursae?
Reduce friction between the two structures during extension and flexion of the arm
Where is the subcutaneous bursa found?
Between the olecranon and the overlying connective tissue
Why are bursae clinically important?
They can become irritated and inflamed, producing pain
What is subcutaneous bursitis?
Inflammation of the subcutaneous bursa
What can cause the bursa to become inflamed?
Repeated friction and pressure on the bursa
What can happen to the subcutaneous bursa?
It can become infected, which would cause inflammation
Why can the subcutaneous bursa get infected?
Because the bursa lies relatively superficially
What causes subtendinosus bursitis?
Repeated flexion and extension of the forearm
What usually happens in subtendinosus bursitis?
Usually, flexion is more painful as more pressure is put on the bursa
When does an elbow dislocation usually occur?
When a young child falls on a hand with the elbow flexed
What happens in an elbow dislocation?
The distal end of the humerus is driven through the weakest part of the joint capsule
What is the weakest part of the joint capsule of the elbow joint?
The anterior side
What usually happens in an elbow dislocation?
The ulnar collateral ligament is usually torn, and their can also be ulnar nerve involvement
In what direction are most elbow dislocations?
Posterior
How are elbow dislocations named?
By the position of the ulna and radius, not humerus
What do most of the flexor and extensor muscles in forearm have?
A common tendinous origin
Where do the flexor muscles originate from?
The medial epicondyle
Where do the extensor muscles originate from?
The lateral epicondyle
What can sportspeople develop?
An overuse strain of the common tendon of the flexor and extensor muscles
What does an overuse strain of the common tendon result in?
Pain and inflammation around the area of the affected epicondyle
What is overuse strain of the common tendon called?
Epicondylitis (Tennis elbow, or Golfer’s Elbow)
How does a supraepicondylar fracture occur?
By falling on a flexed elbow
What kind of fracture is a supraepicondylar fracture?
A transverse fracture
Where does asupraepicondylar fracture span?
Between the two epicondyles
What can asupraepicondylar fracture cause?
Interference to the blood supply of the forearm via the brachial artery
Damage to the medial, ulnar or radial nerves
Why can asupraepicondylar fracture lead to interference to the brachial artery?
Due to direct damage, or swelling
What can the resulting ischaemia from disruption to the blood supply caused by asupraepicondylar fracture lead to?
Volkmann’s ischaemic contracture
What happens in a Volkmann’s ischaemic contracture?
Uncontrolled flexion of the hand
What causes Volkmann’s ischaemic contracture?
The flexor muscles become fibrotic and short
