MSK: Trauma and Overuse, Elbow and Forearm

Question 1

What is the most common cause of an elbow joint effusion?

Answer 1

Adults: Radial head fracture
Pediatrics: Supracondylar fracture

Question 2

Answer 2

Elbow joint effusion, suspicious for occult fracture

Note: The posterior fat pad is visible (“sail sign”).

Question 3

Posterior elbow dislocations are often associated with…

Answer 3

Capitellum fracture

Question 4

Which fat pad is more specific for an elbow effusion?

Answer 4

The posterior fat pad

Note: You can see the anterior fat pad sometimes in normal elbows.

Question 5

What can cause a falsely elevated posterior fat pad on a lateral elbow radiograph?

Answer 5

If the radiograph is not a true 90 degree flexed lateral image

Question 6

Next step

Answer 6

If you see a radial head fracture/dislocation, recommend wrist radiographs to look for another fracture/dislocation in the forearm “ring.”

Question 7

Next step

Answer 7

If you see a distal ulna fracture/dislocation, recommend elbow radiographs to look for another fracture/dislocation in the forearm”ring.”

Question 8

What are the major eponymous forearm fractures?

Answer 8

• Monteggia (proximal fracture dislocation)
• Galeazzi (distal fracture dislocation)
• Essex-Lopresti (proximal fracture and distal dislocation)

Question 9

Answer 9

Monteggia fracture (Fracture of the proximal ulna with dislocation of the radial head)

Note:
Proximal forearm fracture/dislocation (monteggiA = proximal alphabet).

“MUgr” (Monteggia = ulnar fracture).

Question 10

Answer 10

Galeazzi fracture (Fracture of the radial shaft with anterior dislocation of the distal ulna)

Note:
Distal forearm fracture/dislocation (galeaZZi = distal alphabet).

“muGR” (Galeazzi = radial fracture).

Question 11

Which eponymous forearm fracture is common in children, but rare in adults?

Answer 11

Monteggia fracture/dislocation

Question 12

What are the components of a Monteggia fracture?

Answer 12

• Fracture of the proximal ulna
• Dislocation of the radial head

Note:
Proximal forearm fracture/dislocation (monteggiA = proximal alphabet).

“MUgr” (Monteggia = ulnar fracture).

Question 13

What are the components of a Galeazzi fracture?

Answer 13

• Fracture of the radial shaft
• Dislocation of the distal ulna

Note:
Distal forearm fracture/dislocation (galeaZZi = distal alphabet).

“muGR” (Galeazzi = radial fracture).

Question 14

What are the components of an Essex-Lopresti fracture?

Answer 14

• Fracture of the radial head
• Dislocation of the distal ulna

Question 15

Is an Essex-Lopresti fracture unstable?

Answer 15

It is unstable if there is rupture of the interosseous membrane

Question 16

Answer 16

Essex-Lopresti fracture (fracture of the radial head with dislocation of the distal ulna)

Note: Unlike Monteggia and Galeazzi fractures, Essex-Lopresti involved both the elbow and wrist.

Question 17

What is a classic cause of cubital tunnel syndrome?

Answer 17

An accessory anconeus muscle

Note: In real life, the most common cause of cubital tunnel syndrome is repetitive valgus stress.

Question 18

Arrow

Answer 18

Accessory anconeus muscle (AKA anconeus epitrochlearis)

Note: This can cause cubital tunnel syndrome. The normal anconeus muscle is on the lateral side of the elbow.

Question 19

Where is the cubital tunnel?

Answer 19

Between the olecranon and the medial epicondyle (deep to the cubital tunnel retinaculum, AKA Osborne’s ligament)

Question 20

What travels in the cubital tunnel?

Answer 20

Ulnar nerve

Question 21

Clinical manifestations of cubital tunnel syndrome

Answer 21

Ulnar nerve paresthesias (affecting the pinky and ulnar aspect of the 4th digit)

Question 22

Answer 22

Cubital tunnel syndrome

Note: Edema and enlargement of the ulnar nerve in the region of the cubital tunnel (olecranon/medial epicondyle).

Question 23

What are the 2 types of epicondylitis? Which is more common?

Answer 23

Lateral epicondylitis (i.e. tennis elbow due to repetitive extension) is more common

Medial epicondylitis (i.e. golfers elbow due to repetitive flexion) is less common

Question 24

What is injured in lateral epicondylitis?

Answer 24

• Extensor tendon (classically the extensor carpi radialis brevis)
• Radial collateral ligament complex

Question 25

What is injured in medial epicondylitis?

Answer 25

• Common flexor tendon
• Ulnar nerve (possible if long term)

Question 26

Answer 26

Lateral epicondylitis (AKA tennis elbow)

Note: The lateral epicondyle is on the radial side.

Question 27

Answer 27

Medial epicondylitis (AKA golfer’s elbow)

Note: The medial epicondyle is on the ulnar side.

Question 28

Answer 28

Partial medial ulnar collateral ligament tear

Note: This is the “T sign” and is common in pitchers.

Question 29

Where does the ulnar collateral ligament attach?

Answer 29

The sublime tubercle on the medial coronoid

Question 30

This injury is most common in what pt population?

Answer 30

Pitchers (due to repeated valgus overload)

Question 31

The ulnar collateral ligament has 3 bundles. Which is the most important?

Answer 31

Anterior bundle

Question 32

Answer 32

Little leaguer elbow (medial epicondyle chronic injury)

Note: This is any repetitive, chronic injury to the medial epicondyle (stress fracture, avulsion, or delayed closure of the medial epicondylar apophysis).

Question 33

Little leaguer elbow

Answer 33

Any repetitive, chronic injury to the medial epicondyle (stress fracture, avulsion, or delayed closure of the medial epicondylar apophysis)

Note: This is often associated with an ulnar collateral ligament injury.

Question 34

Valgus overload syndrome

Answer 34

A chronic elbow injury seen in some pitchers, resulting in:

• Ulnar collateral ligament injury
• Arthritis at the posterior humerus/ulna
• Osteochondral defect at the capitellum

Question 35

Medial epitrochlear ultrasound

Answer 35

If you see medial trochlear lymphadenopathy, think cat-scratch disease (i.e. Bartonella infection)

Question 36

Olecranon bursitis is commonly seen in…

Answer 36

Pts on dialysis (AKA dialysis elbow), due to constant pressure from positioning during dialysis

Question 37

Common cause of biceps tear

Answer 37

Weight lifting (bad deadlift form)

Question 38

What is the most common location for a complete biceps tear?

Answer 38

In the shoulder (with the tendon avulsing off the labrum or at the level of the bicipital groove)

Question 39

Partial biceps tears are often associated with…

Answer 39

Bicipitoradial bursitis

Note: Median nerve injury can also occur.

Question 40

Answer 40

Bicipitoradial bursitis

Note: This is often seen with partial biceps tendon tears.

Question 41

Answer 41

Avulsion of the triceps tendon

Note: This is often associated with a Type 2 Salter Harris fracture of the olecranon in children.

Question 42

Answer 42

Olecranon bursitis

Question 43

Answer 43

Olecranon bursitis

Question 44

Answer 44

Olecranon bursitis

Question 45

What is the second most commonly dislocated large joint in the adult?

Answer 45

Elbow

Note: Shoulder dislocations are the most common.

Question 46

What fractures are commonly associated with elbow dislocations?

Answer 46

• Radial head fracture (most common)
• Coronoid process fracture

Question 47

Answer 47

Posterior elbow dislocation

Question 48

Answer 48

Medial elbow dislocation

Question 49

Posterolateral rotary instability of the elbow

Answer 49

The pattern followed during posterior elbow dislocation that starts in the posterolateral corner due to a lateral ulnar collateral ligament rupture and then leads to dislocation