Elbow and joints of forearm

Question 1

What type of joint is the elbow?

Answer 1

-Hinge-type synovial joint

Question 2

At full extension of the forearm, what is the angle of the humerus with the ulna?

Answer 2

-170 degrees

Question 3

What is the carrying angle?

Answer 3

-The angle between the forearm and the trunk at rest

Question 4

What muscles are responsible for flexion at the elbow?

Answer 4

• Biceps Brachii
• Brachialis
• Brachioradialis
• Palmaris Longus (weak)

Question 5

What muscles are responsible for extension of the elbow?

Answer 5

-Triceps Brachii

Question 6

-What does the fibrous capsule cover at the elbow?

Answer 6

• The elbow joint

- The proximal radioulnar joint

Question 7

Why is the capsule of the elbow weak anteriorly and posteriorly?

Answer 7

-To allow movement

Question 8

What are the collateral ligaments?

Answer 8

-Ligaments on the medial and lateral sides of the capsule (ulnar and radial, respectively) which provide strength

Question 9

What is beneath the fibrous capsule?

Answer 9

-Synovial membrane (secreting lubricating fluid)

Question 10

Describe the ulnar collateral ligament

Answer 10

-Has 3 bands
anterior -> strongest, cord-like band
posterior -> fan-like band
oblique-> deepens the socket for trochlea and provides additional stength

Question 11

Describe the radial collateral ligament

Answer 11

• Fan-like
• Blends with the annular ligament
• Prevents dislocation

Question 12

What are the two most clinically relevant bursae?

Answer 12

• Subcutaneous olecranon bursa

- Subtendinous olecranon bursa

Question 13

Where does the radial nerve pass the elbow?

Answer 13

-Anterior to lateral epicondyle

Question 14

Where does the ulnar nerve pass the elbow?

Answer 14

-Posterior to medial epicondyle

Question 15

Describe the blood supply to the elbow

Answer 15

-Arterial anastamoses surround the elbow formed by collateral arteries and recurrent branched of the ulnar, radial and interosseous arteries

Question 16

What are the three joints in the forearm?

Answer 16

• Proximal radioulnar
• Interosseous membrane
• Distal radioulnar

Question 17

What do the joints of the forearm allow?

Answer 17

-Pronation and supination

Question 18

What type of joint is the proximal radioulnar joint?

Answer 18

-Pivot joint

Question 19

What articulations are involved in the proximal radioulnar joint?

Answer 19

• Radial head

- Radial notch of ulna

Question 20

What is the anatomical location of the annular ligament, including its insertions?

Answer 20

-A ligament which arises from the ulna, wraps around the head of the radius and attaches posteriorly to the radial notch of the ulna to form a ligamentous collar

Question 21

What is pulled elbow?

Answer 21

-A common sublaxation of radial head from annular ligament

Question 22

Why is pulled elbow common in children?

Answer 22

-Annular ligamentt hasnt yet adapted funnel-like arrangement and isnt taut

Question 23

What type of joint is the interosseous membrane?

Answer 23

-Fibrous joint

Question 24

In which direction do the fibres of the membrane run? Why is this important?

Answer 24

• Inferio-medially

- Allows distribution of force from radius to ulna as the radius recieves force first as it lays more distal

Question 25

What articulations are involved in the proximal radioulnar joint?

Answer 25

-Head of ulna with ulnar notch of radius

Question 26

What is the function of the articular disk of the distal radioulnar joint?

Answer 26

- To maintain structure and joint integrity during pronation and supination - Separates cavity of distal radioulnar joint from wrist cavity

Question 27

What are the articulations at the elbow?

Answer 27

- Olecronon fossa with olecranon - Trochlea with trochlear notch - Coronoid process with coronoid fossa - Radial head with capitulum - Radial head with radial fossa

Question 28

What is the sacciform recess?

Answer 28

-A superior extension of the synovial capsule which allows twisting of the capsule during movement

Question 29

What muscles are responsible for supination?

Answer 29

- Biceps brachii | - Supinator

Question 30

What musclees are responsible for pronation?

Answer 30

- Pronator quadratus | - Pronator teres

Question 31

What articulations occur at the wrist?

Answer 31

-Distal radius and articular disk with scaphoid, lunate and triquitrum

Question 32

Name the ligaments of the wrist

Answer 32

- Radial collateral ligament - Ulnar collateral ligament - Palmar radiocarpal ligaments -> ensures hand follows raduis in supination - Dorsal radiocarpal ligaments-> ensures had follows radius during pronation

Question 33

What are the movements of the wrist?

Answer 33

- Flexion/Extension - ABduction (Radial deviation) - ADduction (ulnar deviation)

Question 34

What is a colles fracture?

Answer 34

-Fracture which occurs in distal radius causing posterior displacement of the distal fragment (dinnerfork deformity)

Question 35

What is a possible complication of fracture of scaphoid? Why?

Answer 35

-Avascular necrosis as blood supply comes distally

Question 36

Where would you clinically examine for tenderness if a scaphoid fracture was suspected?

Answer 36

-Over the anatomical snuff box