Common Injuries in Radiology of the Upper and Lower Limb

Question 1

Causes of a fractured clavicle

Answer 1

• Indirect trauma (FOOSH or blow to shoulder)
• Direct trauma

Question 2

What penetrating injuries are a worry for a fractured clavicle?

Answer 2

• Pneumothorax
• Skin perforation

Question 3

Which 1/3 of the clavicle is most commonly fractured?

Answer 3

Middle

Question 4

Why is the superior clavicle fragment displaced superiorly?

Answer 4

Sternocleidomastoid pulls it up

Question 5

Associated injuries of a dislocated shoulder

Answer 5

• Injury to axillary neurovascular bundle
• Injury to axillary nerve
• Associated fracture of humeral head

Question 6

Where does the axillary nerve lie in respect to the humerus?

Answer 6

Wraps around neck of humerus from posterior to anterior

Question 7

What does the axillary nerve supply?

Answer 7

• Deltoid + teres minor
• Skin over deltoid (regimental badge area)

Question 8

Which structures are at risk from a proximal, neck and distal humeral fracture?

Answer 8

• P = axillary nerve
• N = radial nerve
• D = median nerve, brachial artery

Question 9

What sign shows radial nerve injury after a humeral shaft fracture?

Answer 9

Wrist drop

Question 10

Are the anterior and posterior fat pads usually visible on X-ray of the elbow, and if not when do they become visible?

Answer 10

• A = yes
• P = no (visible after effusion)

Question 11

What is the anterior humeral line?

Answer 11

Line drawn down anterior humerus passing through middle 1/3 of capitulum

Question 12

When would the anterior humeral line not pass through the middle 1/3 of capitulum?

Answer 12

Supracondylar fracture

Question 13

What is the radiocapitellar line?

Answer 13

Line bisecting radial shaft passing through capitulum

Question 14

What is suspected is the radiocapitellar line does not pass through the capitulum?

Answer 14

Radial head dislocation or capitellar displacement

Question 15

What causes a supracondylar fracture?

Answer 15

Children FOOSH leading to hyperextension

Question 16

Early and late complications of a supracondylar fracture

Answer 16

• Early:
  > Compartment syndrome
  > Brachial artery injury
  > Nerve injury (median, ulnar, radial)
• Late:
  > Stiffness
  > Volkmann’s ischaemic contracture
  > Heterotopic calcification
  > Mal-union (cubitus valgus/varus)

Question 17

What causes a coronoid avulsion fracture?

Answer 17

Avulsion by brachialis muscle

Question 18

What are carpal fractures usually caused by?

Answer 18

• Compressive loads to hyperextended wrist
• Hyperflexion
• Rotation loading against flexed wrist

Question 19

Which carpal bone is most commonly fractured?

Answer 19

Scaphoid

Question 20

Colle’s vs Smith’s fracture

Answer 20

• Colle’s = dorsal displacement of distal fragment
• Smith’s = volar displacement of distal fragment

Question 21

Which aspects of the pelvis/proximal femur are prone to avulsion?

Answer 21

• Iliac crest
• ASIS
• AIIS
• Ischial tuberosity
• Symphysis
• Greater trochanter
• Lesser trochanter

Question 22

Internal vs external rotation of hip

Answer 22

Leg at 90° anteriorly:
- Internal = move foot laterally
- External = move foot medially

Question 23

What does a posterior hip dislocation look like on X-ray?

Answer 23

• Femoral head displaced superiorly
• Femur internally rotated –> less lesser trochanter prominence
• More greater trochanter prominence

Question 24

What does an anterior hip dislocation look like on X-ray?

Answer 24

• Femoral head displaced superiorly
• Lesser trochanter more prominent (external rotation of femur)

Question 25

Which arteries are at risk in a femoral shaft fracture?

Answer 25

• Superficial femoral artery
• Popliteal artery (if displaces into popliteal fossa)