132 - Joints of Upper Limb 2. Elbow & Radioulnar Joints

Question 1

Type of joint that elbow joint it

Answer 1

Hinge joint.

Question 2

Type of joint that radio-ulner joint is

Answer 2

Pivot joint

Question 3

Part of humerus that radius articulates with

Answer 3

Capitulum

Question 4

Part of humerus that ulna articulates with

Answer 4

Trochlea

Question 5

Part of elbow joint that prevents hyperextension

Answer 5

Olecranon, from ulna

Question 6

Fossa on humerus that ulna fits into during flexion

Answer 6

Coronoid fossa that coronoid (on ulna) fits into.

Question 7

What limit lateral movement of elbow joint?

Answer 7

Medial and lateral collateral ligaments

Question 8

What join the medial epicondyle on the elbow?

Answer 8

Superficial flexors of the forearm.

Medial collateral ligament

Question 9

What join the lateral epicondyle on the elbow?

Answer 9

Superficial extensors of the forearm.

Lateral collateral ligament

Question 10

Location of insertion of biceps

Answer 10

Antero-medial part of proximal radius

Question 11

Elbow complex
1
2

Answer 11

• Elbow joint
• Proximal radioulnar joint
- both joints share one synovial cavity

Question 12

Location of elbow complex capsule

Answer 12

Goes above fossae on humerus.

Attaches anteriorly above radial articulation.

Question 13

Things that reinforce elbow joint
1
2
3
4
5

Answer 13

Ligaments:
-collateral
-medial/ ulnar (MCL)
-lateral/ radial (LCL)
-annular*
-attachment between
LCL & annular ligament permits pronation/ supination

Question 14

*Things that reinforce elbow joint

Answer 14

ELBOWCOMPLEX

Question 15

Ligaments that allow pronation and supernation of forearm

Answer 15

Lateral collateral ligament and annular ligament

Question 16

How do the lateral collateral ligament and annular ligament allow pronation and supernation of forearm?

Answer 16

Lateral collateral ligament attaches to annular ligament (which is on the ulna)

Question 17

Non-communicating bursa in elbow

Answer 17

Olecranon bursa

Question 18

Stability of elbow joint

Answer 18

Very stable

Question 19

Angles of joints in the elbow

Answer 19

Medial epicondyle, olecranon process, lateral epicondyle are all in alignment.

At flexion these form an isosceles triangle

Question 20

Valgus displacement of forearm

Answer 20

At extension, forearm is angled at about 15 degrees to arm.

This disappears in flexion.

Question 21

What happens if there is an increase in valgus angle of forearm?

Answer 21

Puts additional tension on structures on medial aspect of elbow.
EG: Ulnar nerve

Question 22

Name for interior of elbow

Answer 22

Cubital fossa

Question 23

Where does brachial artery split?

Answer 23

At head of radius, in cubital fossa (into radial and ulnar arteries)

Question 24

What fill fossae in elbow when not occupied by bone?

Answer 24

Fat pads

Question 25

Effect of annular ligament on elbow capsule in flexion

Answer 25

Makes capsule bend laterally with flexion

Question 26

Types of epiphyses in elbow

Answer 26

Traction epiphyses

Question 27

Radio-ulnar joints 1 2

Answer 27

Two synovial picot joints. 1) Superior RU Joint - Within elbow complex 2) Inferior RU joint - With triangular fibrocartilaginous complex (disc)

Question 28

Ligament around which radio-ulnar joint rotates

Answer 28

Annular ligament on ulnar

Question 29

Reason for direction of fibres in interosseous membrane in radioulnar joint 1 2

Answer 29

1) Provide sites of attachment for deep flexor and extensor muscles in forearm. 2) Transmit force from radius to ulnar

Question 30

What separates ulnar bone from articulating with the wrist?

Answer 30

Triangular interosseous disc

Question 31

Quadrate ligament

Answer 31

Vestigial ligament in the radio-ulnar interosseous membrane

Question 32

Relationship between fractured radius and ulnar bones

Answer 32

If one is fractured, the other normally fractures

Question 33

Effect of age on triangular interosseous ligament in wrist

Answer 33

Disc increasingly perforated with age (7% in 3rd decade, 50+% in 6th decade)

Question 34

Pronator muscles 1 2

Answer 34

1) Pronator teres (power pronation) | 2) Pronator quadratus (more fine movement)

Question 35

Supinator muscles

Answer 35

Biceps brachii

Question 36

'Student's elbow'

Answer 36

Olecranon bursitis (in elbow)

Question 37

Pulled elbow

Answer 37

Annular ligament is weaker in children. | Pulling on a fully-extended elbow can pull the radial head out of annular ligament

Question 38

Most common direction of elbow dislocation

Answer 38

Posterior

Question 39

Volkmann's ischaemia

Answer 39

When a supracondylar fracture occurs (on humerus), brachial artery can be endangered. Stretch, spasm of brachial artery can lead to ischaemia of forearm musculature.

Question 40

Structure at risk when there is a fracture of the medial epicondyle

Answer 40

Ulnar nerve

Question 41

On which bone is the annular ligament located?

Answer 41

Radius