Elbow

Question 1

What 2 articulations make up the elbow joint?

Answer 1

• HUMERO-ULNAR (trochlea of humerus and trochlear notch of ulna)
• Humero-radial (capitulum of humerus, and upper surface of radial head)

Question 2

What reinforces the elbow capsule?

Answer 2

Laterally - radial collateral ligament
Medially - ulnar collateral ligament
(Thin post/ant - allows flexion/extension)

Question 3

What type of dislocation of the elbow occurs 80-90% of the time?

Answer 3

Posterior.

-humerus goes ant, radius and ulnar project post

Question 4

What are the 2 main causes of posterior dislocation of the elbow?

Answer 4

FOOSH -elbow flexed

-Hyperextension

Question 5

What are 3 findings with post elbow dislocation?

Answer 5

• Ulnar collateral ligament torn
• Fractures to radial head, coronoid procees & olecranon process
• Ulnar nerve injury

Question 6

Where does the ulnar nerve pass in the elbow joint?

Answer 6

Between the olecranon process(ulnar) and medial epicondyle(humerus)

Question 7

What muscle in the wrist is supplies by the ulnar nerve?

Answer 7

FCU

Question 8

What is the sensory supply of the ulnar nerve?

Answer 8

Med palm & med 1 1/2 digits

Question 9

What are symptoms of ulnar nerve damage?

Answer 9

• Numb med palm and 1 1/2 digits

- Weak flexion and adduction of the wrist

Question 10

What is the difference between a simple and comple elbow dislocation?

Answer 10

Simple - normally ligamentous, not bone fracture

Complex - associated with bone fracture

Question 11

What normally prevent hyperextension at elbow?

Answer 11

Olecranon contact with olecranon fossa.

NB. some people have olcranon FORAMEN - can hyperextend elbow

Question 12

What are the 3 flexors of the elbow joint?

Answer 12

• brachialis
• biceps brachii
• brachioradialis (when forearm is mid-pronated)

Question 13

What is the extensor at the elbow?

Answer 13

Triceps brachii

Question 14

Why is brachioradialis unusual?

Answer 14

Classified as extensor compartment, but passes ant to elbow

Question 15

What is the origin of triceps brachii? (3)

Answer 15

Long head - infraglenoid tubercle on the scapula
Lateral head - Posterolateral humerus above spinal groove
Medial head - posteromedial humerus below spinal groove

Question 16

What is the common insertion of triceps brachii?

Answer 16

Olecranon process (ulna)

Question 17

Innervation of triceps brachii?

Answer 17

Radial nerve (C5-T1)

Question 18

What is the olecranon bursa?

Answer 18

Synovial fluid sac around olecranon process

Question 19

What is bursitis of the elbow and what causes it?

Answer 19

Inflammation of olecranon bursa.

-Excess repeated pressure/friction

Question 20

What is the annular ligament?

Answer 20

Wraps around head of radius - allows rotation of humerus (pronation/supination)
-NB. weak in childhood - more likely to dislocate

Question 21

What is ‘nursemaids’/pulled elbow syndrome?

Answer 21

Dislocation of radius laterally due to biceps brachii. Common in children (parents swinging arms).

Question 22

What is the proximal radioulnar joint and where is it located?

Answer 22

Articulation between radius head and radial notch (ulnar).

-located in elbow capsule

Question 23

What are the movements of the prox radio-ulnar joint?

Answer 23

Pronation/supination

Question 24

What happens to the radial tuberosity during pronation?

Answer 24

Moves from med to lat

Question 25

What 2 muscles contract to move the forearm from the supinated to pronated position, and what nerve innervates them?

Answer 25

- Pronator teres - Pronator quadratus Innervated by median nerve

Question 26

Which 2 muscles contract to move the forearm from the pronated to suppinated position and what nerves innervate them?

Answer 26

- Supinator - Biceps brachii Innervated by radial nerve/musculocutaneous

Question 27

What is the 1* function of biceps?

Answer 27

Supination (arm)

Question 28

What is golfer's elbow?

Answer 28

Flexor tendon inflammation at med epicondyle

Question 29

What is tennis elbow?

Answer 29

Flexor tendon inflammation at lat epicondyle | Treatment; coritcosteroid injection

Question 30

What is avulsion of the medial epicondyle? | What is a big risk involved?

Answer 30

Medial epicondyle is pulled out of position. - Med epicondyle ossifies separate to humerus - Risk; ulnar nerve stretching

Question 31

What is a common humeral fracture in the elderly? What nerve is often damaged?

Answer 31

Fracture to surgical neck. | -Axillary nerve as it wraps around the surgical neck (test deltoid function and badge area sensation)

Question 32

What commonly occurs in a humeral shaft fracture and what is the possible nerve damage associated?

Answer 32

Bone fractures along radial groove, then deltoid pulls it laterally. Radial nerve may be damaged (>wrist extensor paralysed)

Question 33

What is a supracondylar fracture of the humerus?

Answer 33

Fracture just above condylar; humerus pushed anteriorly. | Common in chiildren.

Question 34

Which vessels and nerves are at risk of damage in a supracondylar fracture?

Answer 34

Median nerve and brachial artery (anterior to humerus). | -hand goes blue (necrosis risk)

Question 35

What are the 4 wrist flexor muscles?

Answer 35

- pronator teres - FCR - palmaris longus - FCU