The Elbow and Radioulnar Joint

Question 1

Describe the actions of the elbow joint

What flexes and extends the elbow

Answer 1

Hinge joint,
-distal end of humerus articulates w proximal radius and ulna

In extension

• triceps brachii, anconeus
• olecranon on ulna articulates with olecranon fossa on humerus
• epicondyles and olecranon aligned

In flexion

• brachialis, biceps brachii, brachioradialis
• olecranon not deep in fossa, forms triangle
• olecranon aligned with humerus

Question 2

Describe the movements of the radius and the ulna in supination and pronation

Answer 2

Head of radius surrounded by anular radial ligament,
-ligament attaches to olecranon and trochlea articulation

Rotation of radius pivots around the ulnar

Question 3

Describe the osteology of the radius and ulnar in terms of their proximal and distal ends

Answer 3

Radius

• thinner proximal head
• thicker distal head

Ulna

• thicker proximal head
• thinner distal head

Question 4

What are the muscles that cause pronation in the radius and ulna

Answer 4

Pronator teres and pronator quadratus

Some contribution from flexor carpi radials and palmaris long’s when mid pronated

Question 5

What are the muscles that cause supination

Answer 5

Mainly by supinator

Biceps brachii involved if more power needed

Question 6

Describe the syndesmosis found between the radius and ulnar
How does it act during supination and pronation
What is its function

Answer 6

Transfers forces from radius to ulna
As forearm supinates, fibres start relaxed => tense (neutral) => relaxed (supine)

Separates ant and post comp
Limits over rotation

Question 7

Describe the ligaments at the proximal radioulnar joint (pivot synovial)

Answer 7

Anular ligament, holds radial head in space

Radial and ulnar collateral ligaments

Proximal radioulnar joint
-articular cavity of joint continuous with elbow joint

Question 8

Name the 2 muscles that articulate at the elbow for flexion

Answer 8

Brachialis

Biceps brachii

Question 9

What are the attachments and actions associated with the

• brachialis
• biceps brachii

Answer 9

Brachialis

• Med and lat humerus => ulna coronoid process
• Forearm flexor
• Unaffected by supination/pronation

Biceps brachii

• Corocoid process (SH), supraglenoid tubercle (LH) => Radius tuberosity
• Forearm flexor when supine
• Supinator when prone

Question 10

Name the 2 muscles that articulate at the elbow for extension

Answer 10

Triceps brachii

Anconeus

Question 11

What are the attachments and actions associated with the

• triceps brachii
• anconeus

Answer 11

Triceps brachii

• Humerus and infraglenoid tubercle => olecranon
• Forearm extensor
• Unaffected by pronation/supination

Anconeus

• Lateral humerus epicondyle => lateral olecranon
• Helps forearm extension

Question 12

Describe the osteology of the elbow joint

Answer 12

Anterior of humerus

• Radial fossa superior to capitulum (articulates with radius)
• Coronoid fossa superior to trochlea (articulates with ulna)

Posterior of humerus
-Olecranon fossa (articulates with olecranon on ulna

Question 13

Name the 3 articulating surfaces of the synovial elbow joint

What is also found at the synovial joint for added protection

Answer 13

Humeroradial, capitulum => fovea of radius
Humeroulnar, trochlea => ulnar trochlear notch
Proximal radioulnar, radius head => radius ulnar notch

Fat pads found in olecranon fossa and coronoid fossa

Question 14

Describe the shape of the ligaments found on the lateral side of the elbow joint

What movements occur here

Answer 14

Fan like radial collateral blends with radial anular ligament

Radial anular ligament, holds radial head in radial notch => pronation and supination

Question 15

Describe the shape of the ligaments found on the medial side of the elbow joint

Answer 15

Oblique cord, band between the ulna and radius
-Deepens trochlea socket

Ulnar collateral ligament

• Anterior band between medial epicondyle and coronoid
• Posterior and oblique band also found here

Question 16

What is the function of the elbow joint

Answer 16

Elbow joint stability

• Hold and encapsulate elements, deepens socket
• Trade off between mobility and stability

Question 17

What is the cubital fossa?
What structures are found superficially here
What structures are found deep here

What is the clinical significance of this area of the arm

Answer 17

Area on the anterior surface of the elbow

Cephalic and median cubital vein superificially

Brachial artery, vein, median nerve, ulnar and radial artery, biceps tendon deep

IV into superficial veins
Catheters in brachial artery
Surgical access to distal humerus

Question 18

Describe the location of the ulnar nerve and its significance

Answer 18

Ulnar nerve exposed, on medial epicondyle of humerus, posterior

Funny bone

Question 19

Name the bursae found at the elbow joint

What pathologies can occur here

Answer 19

Subcutaneous of medial epicondyle
Subcutaneous of lateral epicondyle

Subtendinous bursa of triceps brachii

Infratendinous
Subcutaneous, both part of olecranon bursa
All 3 under tendons of elbow joint

Bursa of anconeous

Trauma => bursitis

Olecranon bursa most likely

Question 20

What is an olecranon fracture

How would you treat this

Answer 20

Attachment for triceps brachii =＞avulsion of olecranon

Surgery, realign and hold with pins, wires, screws

Question 21

What else can happen in a distal humerus/suprachondylar fracture
How would you treat this

Answer 21

Radial nerves/arteries also associated with the fractures

Needs surgical repair with plates and screws

Question 22

What is tennis elbow

Answer 22

Repetitive strain injuries => inflammation of tendons around lateral epicondyle

Question 23

What is golfers elbow

Answer 23

Repetitive strain injuries => inflammation of tendons around medial epicondyle

Question 24

What else can happen in an elbow dislocation

Answer 24

Ulnar collateral torn/or fracture to radial head, coronoid process or olecranon