Bones in elbow joint

Question 1

Distal humerus bony landmarks anterior

Answer 1

Capitulum (articulate with radius head)
Trochlea (articulate with ulna)
Coronoid fossa (for coronoid process of ulna during flexion)
Radial fossa (radial bone during flexion)
Supracondylar ridges

Question 2

Distal humerus posterior landmarks

Answer 2

Olecranon fossa (articulates with olecranon of ulnar during extension)
Trochlea

Question 3

Medial and lateral epicondyles

Answer 3

Lateral - common extensor at elbow origin

Medial - common flexor at elbow origin

Question 4

Proximal ulna parts

Answer 4

Coronoid process
Olecranon
Trochlear notch (trochlea of humerus)
Radial notch (head of radius)
Ulna tuberosity (for brachialis insertion)
Supinator fossa/crest - supinator muscle attaches

Question 5

Where is trochlear notch?

Answer 5

Between olecranon and coronoid process

Question 6

Proximal radius features

Answer 6

Head - covered in articular cartilage, concave (humerus capitulum articulates)
Defined neck
Radial tuberosity - attachment for biceps brachii

Question 7

What is the thickened band around radial head?

Answer 7

Radial notch of ulna articulates here

Question 8

Ulnar shape

Answer 8

Wide and tapers as you go down

Question 9

Elbow joint type

Answer 9

Hinge synovial

Question 10

Elbow joint bones involved

Answer 10

Distal Humerus
Proximal Ulnar
Proximal Radius

Question 11

3 articulations elbow

Answer 11

Humeroradial
Humeroulnar
Radioulnar (proximal)

Question 12

What structure allows for the hinge movements at elbow?

Answer 12

Rounded capitulum

Question 13

What is the main stabilising factor of joint? (bony)

Answer 13

Trochlear notch on ulna

Acts as spanner/wrench gripping onto trochlea of humerus

Question 14

Ligaments stabilising elbow

Answer 14

Radial (lateral) collateral ligament
Ulnar (medial) collateral ligament
Annular ligament

fuse to joint capsule

Question 15

Annular joint function

Answer 15

Stabilise head of radius into radial notch of ulna

Question 16

What does the fibrous capsule cover?

Answer 16

It is continuous with radioulnar joint

Question 17

Where is capsule weak?

Answer 17

Anterior and posterior but strengthened by collateral ligaments

Question 18

Proximal radioulnar joint

Answer 18

pivot synovial

radial head moves + radial notch on ulnar

Question 19

How does annular ligament hold radial head in place?

Answer 19

Collar like
Wraps around radius head allowing rotation
Continuous with fibrous capsule

Question 20

What can occur if annular ligament is damaged?

Answer 20

Subluxation/dislocation of radial head from radial notch

Question 21

Are the radius and ulnar joined anywhere else?

Answer 21

Margins are joined along shaft by interosseus membrane

Question 22

Distal radioulnar joint

Answer 22

Pivot synovial

Radius is the one that moves

Question 23

What is within distal radioulnar joint?

Answer 23

Fibrocartilaginous disc - ‘triangular ligament’

Question 24

What does triangular ligament do?

Answer 24

Separates radioulnar joint from wrist joint

Question 25

What occurs during supination/pronation?

Answer 25

Ulnar is fixed in place
Capitulum of humerus and radial head allow rotation of radius
Radiocarpal joint allows radius to rotate and take hand with it

Question 26

Resting position of hand

Answer 26

Mid-prone

Palm faces towards trunk of body

Question 27

Movements at elbow joint

Answer 27

Flexion and extension

Question 28

when is elbow joint most stable?

Answer 28

When fully flexed (muscles and coronoid process and coronoid fossa stabilise)

When fully extended (olecranon and olecranon fossa stabilise, prevent hyperextension)

Question 29

Features contributing to elbow joint stability

Answer 29

Ligaments
Bony articulations (olecranon and coronoid process)
Muscles (anconeus)

Question 30

Bursae within elbow joint (2)

Answer 30

Subtendinous bursae (between triceps tendon and olecranon, reduce flexion and extension friction)

Subcutaneous bursa (olecranon) - easily inflamed when leaning on elbow

Question 31

Elbow flexors

Answer 31

Biceps Brachii (anterior arm)
Brachialis (anterior arm)
Brachioradialis (posterior forearm)

Question 32

What is brachioradialis known as?

Answer 32

Beer raising muscle

Contributes to flexion when mid pronated

Question 33

brachioradialis O and I

Answer 33

O: supraepicondylar ridge of humerus
I: Distal radius (proximal radial styloid process)

Question 34

Brachioradialis A and I

Answer 34

A: Flexion when mid pronated
I: Radial nerve (posterior)

Question 35

Where does pronation and supination occur?

Answer 35

Radioulnar joint