Scaphoid fracture

Question 1

What is the etymology of scaphoid?

Answer 1

From “skaphos” (G) = boat

Question 2

What is the most common carpal bone fracture?

Answer 2

Scaphoid

Question 3

Which sex and age group are scaphoid fractures most common in?

Answer 3

Men

Aged 20-30 years

Question 4

Which type of injuries can cause scaphoid fractures?

Answer 4

High energy

10% have an associated fracture

Question 5

What percent of patients referred to orthopaedics actually have a scaphoid fracture?

Answer 5

10%

Patient over-referred due to diagnostic uncertainty

Question 6

What are the 3 parts of the scaphoid?

Answer 6

Proximal pole

Waist

Distal pole

Question 7

What is the blood supply to the scaphoid?

Answer 7

Dorsal branch of radial artery - supplies 80% of blood

Enters in the distal pole and travels retrogradely towards the proximal pole

Question 8

How can scaphoid fractures affect the blood supply?

Answer 8

Compromise blood supply

Leads to avascular necrosis (AVN)

The more proximal the scaphoid fracture, the higher the risk of AVN

Question 9

What are the clinical features of a scaphoid fracture?

Answer 9

Often follows high energy trauma

Sudden onset wrist pain and bruising may be present

Tenderness in the floor of the anatomical snuffbox

Pain on palpating the scaphoid tubercle

Pain on telescoping the thumb (i.e., push thumb into wrist)

Question 10

What is the anatomical snuffbox?

Answer 10

a.k.a. radial fossa

Triangular depression found on the lateral aspect of the dorsum of the hand

Located at the level of the carpal bones

Question 11

What are the borders of the anatomical snuffbox?

Answer 11

Lateral - abductor pollicis longus + extensor pollicis brevis tendons (1st extensor compartment)

Medial - extensor pollicis longus tendon (3rd extensor compartment)

Floor - scaphoid + trapezium (distally), radial styloid (proximally)

Question 12

What are the contents of the anatomical snuffbox?

Answer 12

Radial artery

Superficial radial nerve

Cephalic vein

Question 13

What are the main DDx for radial wrist pain?

Answer 13

Distal radial fracture

Alternative carpal bone fracture

Fracture of the base of the 1st metacarpal

Ulnar collateral ligament injury

Wrist sprain

De Quervains tenosynovitis

Question 14

What investigations would you request?

Answer 14

Serial plain radiographs - as scaphoid fractures not always detected by initial radiographs

Patient should have wrist immobilised in a thumb splint and repeat plain radiographs in 10-14 days for further evaluation

If repeat radiographs -ve, but clinical features in keeping with scaphoid fracture do MRI of the wrist - definitive investigations

So interim fracture Mx whilst waiting for MRI

Question 15

What is the Mx of a scaphoid fracture?

Answer 15

Undisplaced = strict immobilisation in a plasta with a thumb spica splint

Displaced = surgery - percutaneous variable-pitched screw; can be placed across the fracture site to compress it

Question 16

What are the complications of a scaphoid fracture?

Answer 16

Avascular necrosis - increased risk the more proximal the fracture

Non-union - most commonly due to poor blood supply ; managed with internal fixation + bone grafts but morbidity is high even with surgical repair

Question 17

Sources

Answer 17

https://teachmesurgery.com/orthopaedic/wrist-and-hand/scaphoid-fractures/