Scaphoid Fractures

Question 1

Most common carpus to fracture

Answer 1

Scaphoid

Question 2

Epidemiology

Answer 2

Men aged 20-30 years with high-energy injury.

10% have associated fractures as well

Question 3

Scaphoid fractures are very commonly referred to orthopaedics.

Why?

Answer 3

Due to diagnostic uncertainty and only 1 in 10 referred patients will actually have a fracture

Question 4

Scaphoid is divided into what?

Answer 4

Three parts

Proximal pole

Waist

Distal pole

Question 5

Explain blood supply to scaphoid.

Answer 5

Braches of radial artery

Dorsal branch of radial artery supplies 80% of the blood and enters at the distal pole leading to retrograde arterial supply

This means that fractures can compromise blood supply and cause avascular necrosis

The more proximal the scaphoid fracture is -> more risk of avascular necrosis

Question 6

Clinical features

Answer 6

Following trauma

Sudden onset of wrist pain and pain in anatomical snuffbox

Bruising might be present

Question 7

Examination findings

Answer 7

Tenderness in floor of the anatomical snuffbox

Pain on palpating the scaphoid tubercle and pain on telescoping of the thumb (pushing thumb into wrist)

Question 8

Tendons of anatomical snuffbox

Answer 8

From lateral to medial

Abductor pollicis longus

Extensor pollicis brevis

Extensor pollicis longus

Question 9

Contents of snuffbox

Answer 9

Radial artery

Superficial radial nerve

Cephalic vein

Question 10

Floor of snuffbox

Answer 10

Scaphoid + trapezium (distally) + radial styloid (proximally)

Question 11

Dx

Answer 11

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 12

Ix

Answer 12

Plain radiographs

MRI scan of wrist if series of X-ray is negative and clinical findings are still suggestive of scaphoid fracture. The MRI will be the definitive diagnosis and interim management will be commenced while awating scan.

Question 13

Explain how X-rays are done in scaphoid fractures.

Answer 13

Scaphoid series with AP, lateral and oblique views

Scaphoid fracture are not always detected on the first X-ray.
Wrist should be immobilised in a thumb splint and X-ray should be repeated 10-14 days for further evaluation

Question 14

What is management determined by?

Answer 14

Location of fracture and degree of fracture

Question 15

Treatment of undisplaced fracture

Answer 15

Strict immobilsation in a plaster with thumb spica splint.

Question 16

When should an undisplaced fracture be treated surgically?

Answer 16

Undisplaced fracture of proximal pole due to high risk of AVN.

Especially warranted if it is a dominant hand in a working-age patient

Question 17

Indications for surgical intervention

Answer 17

Displaced fractures

Question 18

Surgical intervention of displaced scaphoid fractures

Answer 18

Percutaneous variable-pitched screw

Question 19

Complications of scaphoid fracture

Answer 19

Avascular necrosis (30%) and more common in proximal fractures

Non-union where bone fail to heal properly due to poor blood supply (particularly common if the fracture goes undiagnosed)

Question 20

If non-union happens due to an undiagnosed fracture, what can be done?

Answer 20

Internal fixation and bone grafts