Lecture 15

Question 1

What is the nerve supply of the elbow joint?

Answer 1

Musculocutaneous
Radial
Ulnar

Question 2

What are the ligaments of the elbow joint?

Answer 2

Ulnar (medial) collateral ligament:
Anterior, posterior, oblique.
Fans out and diverges to coronoid process.
Blends with bone.

Radial (lateral) collateral ligament:
Blends with annular ligament.

Question 3

What fat pads are found at the elbow joint?

Answer 3

Olecranon

Radial

Coronoid

Question 4

What movements occur at the elbow joint?

Answer 4

Flexion:
Between humerus and ulnar.
Radial contact at close packed position.
Interosseus membrane is strongest at 90 degrees flexion and mid way between pronation and supination.

Extension:
Limited by oblique angle of trochlear

Question 5

What is the blood supply of the elbow joint?

Answer 5

Branches of the brachial artery (radial/ulnar)

Question 6

What is the carrying angle?

Answer 6

Angle created by the arm during elbow extension and forearm supination.
Stops excessive lateral deviation.
Is greater in adults than children.
Is greater in females than males due to the hip.

Question 7

What are the flexion muscles at the elbow joint?

Answer 7

Biceps brachii
Brachialis
Brachioradialis

Question 8

What are the extension muscles at the elbow joint?

Answer 8

Triceps brachii

Anconeus

Question 9

What is the purpose of the interosseus membrane between the radioulnar joints?

Answer 9

Obliquely orientated to transmit forces between the radius to the ulnar.
20% through radius at proximal end.
80% through radius at distal end.

Question 10

What nerve supplies the proximal radioulnar joint?

Answer 10

Median

Musculocutaneous

Radial

Question 11

What artery supplies the proximal radioulnar joint?

Answer 11

Branches of the deep radial and ulnar arteries.

Question 12

What is the purpose of the sacciform recess?

Answer 12

Extension of the joint capsule that allows laxity for supination and pronation to take place.

Question 13

What two bones is the proximal radioulnar joint in between?

Answer 13

The head of the radius and the radial notch of the ulnar.

Question 14

What are the ligaments of the proximal radioulnar joint?

Answer 14

Annular ligament - ring that fits around head of radius

Quadrate ligament - extends to neck of radius, provide extra support

Interosseus membrane

Question 15

What bones is the distal radioulnar joint in between?

Answer 15

Head of ulna and ulnar notch on radius.

Question 16

What is the nerve supply of the distal radioulnar joint?

Answer 16

Median (anterior)

Radial interosseus (posterior)

Question 17

What is the triangular ligament?

Answer 17

Fibrocartilaginous articular disc

Takes the force of supination and pronation

Question 18

What movements occur at the radioulnar joints?

Answer 18

Pronation
Supination
Working along with flexion and extension
Midprone position is the most stable

Question 19

What muscles do pronation ?

Answer 19

Pronator teres
Pronator quadratus

Assisted by:
FCR
Palmaris longus
Brachioradialis

Question 20

What muscles do supination ?

Answer 20

Supinator

Biceps brachii

Assisted by:
Extensor pollicis longus
ECRL

Question 21

Why does the proximal radioulnar joint often dislocate in children?

Answer 21

The annular ligament is lax in children.

Question 22

How does the proximal radioulnar joint dislocate?

Answer 22

Radial head is displaced.

Muscle pulls radial head superiorly.

Question 23

How can a dislocated proximal radioulnar joint be fixed?

Answer 23

Supinate forearm
Push proximally
Joint in flexion

Question 24

Where can avulsion fractures occur?

Answer 24

Medial epicondyle of humerus (ulnar nerve is endangered).
Styloid process of ulnar

Fall on a flexed elbow:
Olecranon process of ulna
Coronoid process of ulna

Question 25

What are the clinical considerations at the humeroulnar and radioulnar joints?

Answer 25

Bursitis
Epicondylitis
Avulsion fractures
Supracondylar fracture of humerus - Volkmann’s ischemic contracture