21B - Elbow Flashcards
What is the principle means by which we lenthen/shorten our limb?
Elbow
The elbow is a … joint meaning …
Compound joint meaning it is actually 3 joints in 1.
1. Humero-ulnar Joint
2. Humero-radial joint
> together form a pure hinge joint of 135 degress flexion/extension
3. Superior Radio-ulnar joint
> provides for pronation/supination (rotatory movements of the radius around the long axis of the ulna)
What is the lateral inferior bony prominence of the humerus and what does it articulate with?
Capitulum - articulates with the radius
What is the medial inferior bony prominence of the humerus and what does it articulate with?
Trochlea (pulley) articulates with the trochlear notch of the ulna
During elbow flexion the … fossa anteriorly is filled with the …
Radial Fossa laterally is filled by the head of the radius
Coronoid Fossa medially is filled by the coronoid process of the ulna
During elbow extension the … fossa posteriorly is filled with the …
Olecranon fossa is filled by the olecranon process of the ulna
The superior radio-ulnar joint occurs at the …
Medial head of the radius and the radial notch of the ulnar laterally
What joints does the fibrous capsule enclose?
All 3 (humero-ulnar, humero-radial, radio-ulnar)
Where does the joint capsule attach?
Superiorly: Above the coronoid and radial fossa of the anterior humerus and olecranon fossa of tee posterior humerus
Inferiorly: Edges of the trochlea notch of ulna and annular ligament around the head of the radius
What ligaments reinforce the joint capsule?
The ones that love you xxx like i do tehe
- medial and lateral collateral ligaments
- anteriorly by tendon of brachialis
- inferiorly by tendon of triceps
Coronoid fossa …
Above trochlea medially on humerus. Articulates with coronoid process of anterior ulna during flexion
> enables an increase in the range of movement during full flexion
> increases stability and congruence of bones
Trochlea …
Medial condyle of humerus. Articulates with the trochlea notch on anterior olecranon
Capitulum …
Lateral condyle of humerus. Articulates with the superior surface of the radius. Allows the radial head to PIVOT for supination/pronation
Radial fossa …
Lateral humerus above capitulum - articulates with head of radius during flexion
Can you see the trochlea and capitulum posteriorly?
Only the trochlea. Can’t see capitulum posteriorly
Radial notch …
Is on the lateral proximal ulna beside the olecranon/trochlear notch
Where is there a bursa at the elbow joint?
Between the olecranon and the skin (can palpate)
Olecranon fossa …
On posterior humerus - enables full extension without bones impinging
Supinator crest …
Is on the posterior ULNA laterally
Coronoid process …
Anterior proximal ulna - articulates with coronoid fossa during flexion
What are the ligaments of the elbow joint?
there are 3
- medial collateral
- lateral collateral
- ANNULAR ligament
Medial collateral ligament of elbow?
Medial epicondyle > medial ulnar
> the ulnar nerve passes behind the epicondyle and lies on top of the medial collateral ligament (funny bone)
> prevents excessive adduction
Lateral collateral ligament of the elbow?
CAN’T run from lateral epicondyle to the lateral radius as it would IMPEDE on the bone during pronation/supination
> runs from lateral epicondyle to ANNULAR LIGAMENT
> prevents excessive abduction
Where is the annular ligament attached and what does it do?
- attached to the anterior and posterior edges of the radial notch on the ulna where the head of the radius articulates
- surrounds the head of the radius
- allows the head of the radius to spin within the loop during pronation/supination
- sacciform synovial membrane will be found here
Where at the elbow joint will you find a sacciform synovial membrane?
Below the annular ligament to lubricate during pro/sup.
