Elbow conditions

Question 1

What type of fracture is a fracture of the medial epicondyle of the humerus?

Answer 1

An avulsion fracture

Question 2

What is an avulsion fracture?

Answer 2

Fracture where fragment of bone is pulled away from main bone mass

Question 3

What is the mechanism of a medial epicondylar fracture of the humerus?

Answer 3

Arm is extended
Extremely abducted at elbow
Pulls ulnar collateral ligament
Pulls off medial epicondyle from rest of humerus

Question 4

Which nerve is most likely injured by a medial epicondylar fracture of the humerus? Why?

Answer 4

Ulnar nerve

because it runs behind the medial epicondyle

Question 5

What type of injury does the ulnar nerve suffer in a medial epicondylar fracture of the humerus?

Answer 5

Nerve traction - stretching

Question 6

An elbow dislocation is usually what type of dislocation?

Answer 6

Posterior dislocation

Question 7

What are the causes of elbow dislocation?

Answer 7

Falling onto outstretched hand, elbow joint flexes

Hyperextension of elbow joint

Question 8

What happens in an elbow dislocation?

Answer 8

Distal humerus driven through anterior part of joint capsule, the weakest part

Radius and ulna move posteriorly

Question 9

What are the complications of an elbow dislocation?

Answer 9

Tearing of ulnar collateral ligament

Fracture of coronoid process or olecranon

Fracture of head of radius

Ulnar nerve injury

Question 10

What is a pulled elbow?

Answer 10

Subluxation of the elbow joint - incomplete dislocation

Question 11

What is partially dislocated in a pulled elbow?

Answer 11

The head of the radius in the elbow joint and proximal radioulnar joint

Question 12

What is a pulled elbow caused by?

Answer 12

Pulling on extended and pronated forearm

Question 13

What happens in a pulled elbow?

Answer 13

Tearing of annular ligament
Radial head moves distally out of socket formed by annular ligament
Annular ligament becomes trapped between radial head and capitulum of humerus

Question 14

How does a pulled elbow present?

Answer 14

Elbow is flexed

Forearm is pronated

Question 15

What is olecranon bursitis?

Answer 15

Inflammation of the bursa in the elbow joint

Question 16

Which bursae may become inflamed in olecranon bursitis?

Answer 16

Subcutaneous bursa

Subtendinous bursa

Question 17

What causes inflammation of the subcutaneous bursa?

Answer 17

Repeated pressure and friction by falls on elbow

Infection by abrasions over elbow

Question 18

What causes inflammation of the subtendinous bursa?

Answer 18

Excessive friction between triceps brachii tendon and olecranon
due to repeated flexion and extension of elbow

Question 19

Which is more commonly inflamed - subcutaneous bursa or subtendinous bursa?

Answer 19

Subcutaneous bursa

Question 20

When is olecranon bursitis more painful - flexed elbow or extended elbow? Why?

Answer 20

Flexed elbow

More pressure exerted on inflamed bursa

Question 21

How is olecranon bursitis treated?

Answer 21

Compression bandaging
Aspiration
If infected - surgical drainage, washout, antibiotics
If chronic - hydrocortisone injections

Question 22

What is a Colles’ fracture?

Answer 22

Type of fracture of the distal radius and ulna

Question 23

What type of fracture does the distal radius show in a Colles’ fracture?

Answer 23

Transverse fracture

Question 24

What type of fracture does the distal ulnae show in a Colles’ fracture?

Answer 24

Avulsion fracture of ulnar styloid process

Question 25

What causes a Colles' fracture? Give an example

Answer 25

Forced extension of wrist | e.g. falling on outstretched hand

Question 26

How do the bone fragments displace in a Colles' fracture?

Answer 26

Distal bony fragment of radius displaces dorsally

Question 27

Why is there shortening of the forearm with a Colles' fracture?

Answer 27

Distal fragment of radius overrides proximal fragment

Question 28

How does a Colles' fracture present?

Answer 28

Dinner fork deformity - abnormal curvature in distal posterior forearm

Question 29

Do Colles' fractures heal well or not? Why?

Answer 29

Yes they do | rich blood supply to distal radius

Question 30

What is a complication of a Colles' fracture in children?

Answer 30

Fracture may pass through epiphyseal plate of radius may malalign during healing disturbs growth of radius

Question 31

What is a Smith's fracture?

Answer 31

Type of fracture of distal radius and ulna

Question 32

What causes a Smith's fracture? Give an example

Answer 32

Forced flexion of wrist | e.g. falling onto a flexed wrist

Question 33

How do the bone fragments displace in a Smith's fracture?

Answer 33

Distal radius fragment displaces anteriorly

Question 34

What causes a scaphoid fracture? Give an example

Answer 34

Hyperextension of wrist | e.g. falling onto an outstretched hand

Question 35

How does a scaphoid fracture present?

Answer 35

Tenderness in anatomical snuffbox

Question 36

When are scaphoid fractures visible on an X-ray?

Answer 36

Don't show up immediately on X-ray | Take 10-14 days to show up

Question 37

What is a complication of a scaphoid fracture?

Answer 37

Avascular necrosis of proximal bony fragment Predisposes to wrist arthritis in later life

Question 38

Why can avascular necrosis occur with a scaphoid fracture?

Answer 38

Because blood supply is distal to proximal | blood supply to proximal fragment is cut off