L6.2 - Joints of the Elbow

Question 1

What type of joint is the elbow joint?

Answer 1

Compound Hinge Synovial Joint

-Compound joint b/n humerus, ulna and radius

Question 2

What two joints does the capsule of the elbow joint consist of?

Answer 2

Humeral ulnar joint (elbow joint) and proximal radioulnar

Question 3

Is there an articular disc (meniscus) in the elbow joint?

Answer 3

No

Question 4

What is a meniscus and where are they found?

Answer 4

Crescent-shaped fibrocartilaginous structure that, in contrast to articular disks, only partly divides a joint cavity.

Present in the knee, wrist, ACJ, SCJ, TMJ

Question 5

Elbow Joint - blood supply?

Answer 5

Branches of the brachial artery as elbow joint is where the cubital fossa is located and where the brachial artery begins to branch off into the ulnar and radial artery.

Question 6

Elbow Joint - nerve supply?

Answer 6

Msc, ulnar, radial

Question 7

During flexion, where does the semilunar notch (upper surface of coronoid process), head of radius make contact with anteriorly?

During extension, where does the olecranon process make contact with posteriorly?

Answer 7

semilunar notch - coronoid fossa
Head of radius - radial fossa

Olecranon process - Olecranon fossa

Question 8

Sacciform recess of elbow joint is?

Answer 8

An extension of the capsule (synovial membrane) of the elbow joint at the neck of the radius - it provides laxity. Also found it Proximal and distal RUJ

Question 9

Fat pads

Answer 9

A pad of fat lying within a joint, covered with synovial membrane and thought to assist in the spreading of synovial lubricant

Question 10

What makes up the ulnar/medial collateral ligament?

Answer 10

Three Bands aka Trivariate band

1) Anterior- starts from CFO to coronoid process
2) Posterior - CFO to olecranon
3) Oblique - Meets up coronoid and olecranon

Question 11

Where does the radial collateral lig. start and end?

Answer 11

Starts at CEO and blends with annular lig. so it doesn’t attach to bone and restrict pronation/supination

Question 12

Where is the elbow joint articular capsule lax?

Answer 12

Ant/Post - allows flex/ex

Question 13

Elbow joint - Where are the fat pads located?

Answer 13

Olecranon, coronoid, radial

Question 14

What layer is the olecranon bursa found it and what is it’s role?

Answer 14

It is found subcutaneously, stopping excessive friction

Question 15

Elbow Joint - What is required for hyperextension to occur?

Answer 15

Enterpicondylar foramen - depression in olecranon fossa

Question 16

Elbow Joint - Position of max stability

Answer 16

Mid prone position - 90 degrees flexion and mid way between pronation/supination

Question 17

What is the carrying angle and is it greater in adults/kids, females/males?

Answer 17

Carrying angle is when the elbow is extended, forearm supinated. The deviation from a straight line occurs in the direction of the thumb. The carrying angle permits the arm to be swung without contacting the hips.

Greater in female adults

Question 18

What is valgus and varus deviation?

Answer 18

VALGUS - 2 structures, distal structure deviates laterally

VARUS - deviates medially

Question 19

What angle does the trochlear have during extension?

Answer 19

Oblique

Question 20

Lateral or medial - which end of trochelea projects more distally?

Answer 20

Medial end

Question 21

Elbow Joint - flexion muscles involved ?

Answer 21

Biceps brachii, brachialis, brachioradialis

Question 22

Elbow Joint - extension muscles involved ?

Answer 22

Triceps brachii, aconeus - working eccentrically

Question 23

Interosseous membrane has ___ fibres - at proximal end only __% through radius. At distal end only __% through radius. Why is it x% for the proximal end? Fracture at one end may lead to _____ at other end.

Answer 23

oblique, 20, 80

At proximal end, by this point - most force already transmitted to ulna.

Dislocation

Question 24

• Proximal RUJ
  1) Where is it found?
  2) What type of joint?
  3) NS
  4) BS
  5) Ligaments

Answer 24

1) B/n head of radius and radial notch of ulna
2) Pivot synovial joint
3) Median, Msc, Radial
4) Branches of deep radial and radial arteries
5) Annular lig, quadrate lig, interossous membrane

Question 25

• Distal RUJ
  1) Where is it found?
  2) What type of joint?
  3) NS
  4) BS
  5) Ligaments

Answer 25

1) B/n head of ulna and ulnar notch of radius
2) Pivot synovial joint
3) Median (ant) and Radial (post) interossesous nerves
4) Ant,post interosseous arteries
5) Ant and post

Question 26

Where is the annular lig. found?

Answer 26

Tight around head of radius, attached to radial notch of ulna, but loosens as it merges with ant/post fibres of elbow joint

Question 27

Where is quadrate ligament found?

Answer 27

It is the extension of annular lig. that attaches to neck of radius - contributes to joint stability by securing the proximal radius against the radial notch, extra support during pro/sup (restricting it).

Question 28

RUJ - Movements, position of max stability

Answer 28

Pro/Sup, midprone position

Question 29

RUJ - Muscles

1) Pronation
2) Supination

Answer 29

1) Pronation
- PT, PQ
- Assisted by FCR, PL, Brachioradialis

2) Supination
- Supinatior, biceps brachii
- Assisted by EPL, ECRL

Question 30

RUJ - Dislocation where? Reduction/treatment?

Answer 30

• Annular lig is lax in children
• Radial head displaced
• Muscles pulls radial head superiorly

REDUCTION/TREATMENT

• Supinate foream
• Push proximally
• Joint in flexion

Question 31

Epicondylitis - Lateral and medial. What sports tend to lead to injury of each side?

Answer 31

Inflammation of tendons surrounding an epicondyle
Lateral - tennis
Medially - golf

Question 32

Supracondylar fracture of humerus could lead to what condition?

Answer 32

Volkmann’s ischemic contracture - permanent flexion contracture of the hand at the wrist, resulting in a claw-like deformity of the hand and fingers. Passive extension of fingers is restricted and painful. It is caused by obstruction on the brachial artery near the elbow.