21B - Elbow

Question 1

What is the principle means by which we lenthen/shorten our limb?

Answer 1

Elbow

Question 2

The elbow is a … joint meaning …

Answer 2

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)

Question 3

What is the lateral inferior bony prominence of the humerus and what does it articulate with?

Answer 3

Capitulum - articulates with the radius

Question 4

What is the medial inferior bony prominence of the humerus and what does it articulate with?

Answer 4

Trochlea (pulley) articulates with the trochlear notch of the ulna

Question 5

During elbow flexion the … fossa anteriorly is filled with the …

Answer 5

Radial Fossa laterally is filled by the head of the radius

Coronoid Fossa medially is filled by the coronoid process of the ulna

Question 6

During elbow extension the … fossa posteriorly is filled with the …

Answer 6

Olecranon fossa is filled by the olecranon process of the ulna

Question 7

The superior radio-ulnar joint occurs at the …

Answer 7

Medial head of the radius and the radial notch of the ulnar laterally

Question 8

What joints does the fibrous capsule enclose?

Answer 8

All 3 (humero-ulnar, humero-radial, radio-ulnar)

Question 9

Where does the joint capsule attach?

Answer 9

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

Question 10

What ligaments reinforce the joint capsule?

The ones that love you xxx like i do tehe

Answer 10

• medial and lateral collateral ligaments
• anteriorly by tendon of brachialis
• inferiorly by tendon of triceps

Question 11

Coronoid fossa …

Answer 11

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

Question 12

Trochlea …

Answer 12

Medial condyle of humerus. Articulates with the trochlea notch on anterior olecranon

Question 13

Capitulum …

Answer 13

Lateral condyle of humerus. Articulates with the superior surface of the radius. Allows the radial head to PIVOT for supination/pronation

Question 14

Radial fossa …

Answer 14

Lateral humerus above capitulum - articulates with head of radius during flexion

Question 15

Can you see the trochlea and capitulum posteriorly?

Answer 15

Only the trochlea. Can’t see capitulum posteriorly

Question 16

Radial notch …

Answer 16

Is on the lateral proximal ulna beside the olecranon/trochlear notch

Question 17

Where is there a bursa at the elbow joint?

Answer 17

Between the olecranon and the skin (can palpate)

Question 18

Olecranon fossa …

Answer 18

On posterior humerus - enables full extension without bones impinging

Question 19

Supinator crest …

Answer 19

Is on the posterior ULNA laterally

Question 20

Coronoid process …

Answer 20

Anterior proximal ulna - articulates with coronoid fossa during flexion

Question 21

What are the ligaments of the elbow joint?

Answer 21

there are 3

• medial collateral
• lateral collateral
• ANNULAR ligament

Question 22

Medial collateral ligament of elbow?

Answer 22

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

Question 23

Lateral collateral ligament of the elbow?

Answer 23

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

Question 24

Where is the annular ligament attached and what does it do?

Answer 24

• 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

Question 25

Where at the elbow joint will you find a sacciform synovial membrane?

Answer 25

Below the annular ligament to lubricate during pro/sup.