Movement lecture 3: Upper limb - elbow

Question 1

Which 2 articulations make up the elbow joint?

Answer 1

Humero-ulnar - between trochlea of the humerus and trochlear notch of the ulna.

Humero-radial - between capitulum and upper surface of radial head

Question 2

Which ligaments reinforce the elbow joint?

Answer 2

Reinforced laterally by the radial collateral ligament

Reinforced medially by the ulnar collateral ligament

Question 3

Why is the elbow joint capsule not reiforced posteriorly or anteriorly?

Answer 3

To allow for flexion and extension.

Question 4

Why is the elbow joint one of the most stable joints in the body?

Answer 4

The good ‘fit’ (congruity) between the trochlear notch of the ulna and trochlea of the humerus.

Question 5

What are the features of posterior elbow dislocation?

Answer 5

The distal end of humerus is driven through the weak anterior part of the joint capsule

Causes:
Fall onto hands with elbows flexed
Hyperextension (blow that drives ulna posteriorly or posterolateral)

Question 6

What findings are sometimes associated with elbow dislocation?

Answer 6

Associated findings:
Ulnar collateral ligament torn
Fractures- head of radius, coronoid process, olecranon process
Ulnar nerve injury

Question 7

What are the consequences of ulnar nerve injury?

Answer 7

Numbness of medial part of palm and medial one and a half fingers

AND weakness of flexion and adduction of the wrist

Question 8

What are the features of a simple elbow dislocation?

Answer 8

No fracture of the bones around the elbow joint: normally ligamentous injury

Good prognosis as often surgery is not required for treatment

Question 9

What are the features of complex elbow dislocation?

Answer 9

Associated with fracture, usually of the forearm.

Surgery is often needed to fix the broken bone in order to maintain the elbow joint in a normal position

Question 10

What normally limits the extension of the elbow?

Answer 10

The olecranon process of the ulna fitting into the olecranon fossa.

Question 11

What abornomality allows for hyperextension of the elbow joint?

Answer 11

The presence of an olecranon foramen instead of an olecranon fossa.

Question 12

What are the three flexors acting at the elbow joint?

Answer 12

Biceps brachii, brachialis and brachioradialis

Question 13

What is the primary flexor of the elbow?

Answer 13

Brachialis

Question 14

What is the function of brachioradialis?

Answer 14

An accessory flexor of elbow joint when forearm is mid-pronated.

Question 15

What is the name of the 1 extensor of the elbow?

Answer 15

Triceps brachii

Question 16

What are the origins of triceps brachii?

Answer 16

Long head - Infraglenoid tubercle (scapula)
Lateral head - Posterolateral humerus above spiral groove
Medial head - Posteromedial humerus below spiral groove

Question 17

What is the insertion of triceps brachii?

Answer 17

Olecranon process

Question 18

What is the innervation of triceps brachii?

Answer 18

Radial nerve C5-T1

Question 19

What is the olecranon bursa?

Answer 19

Bursa that protects the olecranon process of the elbow.

Question 20

What is often the cause of olecranon bursitis?

Answer 20

Excessive, repeated pressure and friction over the olecranon can cause inflammation of the bursa

This causes swelling of the bursa which may be visible and is painful on palpation

Question 21

What is the name of the other joint that lies within the elbow capsule?

Answer 21

The proximal radioulnar joint

Question 22

What is the proximal radioulnar joint?

Answer 22

This is an articulation between the head of the radius and the radial notch of the ulna

Question 23

What is the function of the proximal radioulnar joint along with the annular ligament?

Answer 23

Maintains stability of radius

Allows rotation of the radius during pronation and supination of the forearm.

Question 24

What are the pronator muscles of the elbow?

Answer 24

Pronator teres and quadratus.

Question 25

What are the supinators of the elbow?

Answer 25

Supinator and biceps brachii

Question 26

What is the primary function of biceps brachii?

Answer 26

Supination of the forearm.

Question 27

What are the two common sites of epicondylitis?

Answer 27

Insertions of the wrist extensor tendons into the lateral epicondyle (‘tennis elbow’).

Insertions of wrist flexor tendons into the medial epicondyle (‘golfer’s elbow’)

Question 28

What is avulsion of the medial epicondyle?

Answer 28

Medial epicondyle ossifies separately from the rest of the humerus and is only connected by cartilage until 14-20 years when fusion occurs
Before fusion, severe trauma causing abduction of the elbow stretches the ulnar collateral ligament which can pull the medial epicondyle out of position
Risk of stretching the ulnar nerve

Question 29

What kind of nerve injury is associated with fracture of the surgical neck of the humerus?

Answer 29

Axillary nerve injury – test deltoid function and sensation in regimental badge area

Question 30

Which nerve may be injured by a humeral shaft fracture?

Answer 30

Radial nerve

Question 31

Which nerve may be injured by a supracondylar fracture?

Answer 31

Median nerve