Common Injuries in Radiology of the Upper and Lower Limb Flashcards
Causes of a fractured clavicle
- Indirect trauma (FOOSH or blow to shoulder)
- Direct trauma
What penetrating injuries are a worry for a fractured clavicle?
- Pneumothorax
- Skin perforation
Which 1/3 of the clavicle is most commonly fractured?
Middle
Why is the superior clavicle fragment displaced superiorly?
Sternocleidomastoid pulls it up
Associated injuries of a dislocated shoulder
- Injury to axillary neurovascular bundle
- Injury to axillary nerve
- Associated fracture of humeral head
Where does the axillary nerve lie in respect to the humerus?
Wraps around neck of humerus from posterior to anterior
What does the axillary nerve supply?
- Deltoid + teres minor
- Skin over deltoid (regimental badge area)
Which structures are at risk from a proximal, neck and distal humeral fracture?
- P = axillary nerve
- N = radial nerve
- D = median nerve, brachial artery
What sign shows radial nerve injury after a humeral shaft fracture?
Wrist drop
Are the anterior and posterior fat pads usually visible on X-ray of the elbow, and if not when do they become visible?
- A = yes
- P = no (visible after effusion)
What is the anterior humeral line?
Line drawn down anterior humerus passing through middle 1/3 of capitulum
When would the anterior humeral line not pass through the middle 1/3 of capitulum?
Supracondylar fracture
What is the radiocapitellar line?
Line bisecting radial shaft passing through capitulum
What is suspected is the radiocapitellar line does not pass through the capitulum?
Radial head dislocation or capitellar displacement
What causes a supracondylar fracture?
Children FOOSH leading to hyperextension
Early and late complications of a supracondylar fracture
- Early:
> Compartment syndrome
> Brachial artery injury
> Nerve injury (median, ulnar, radial) - Late:
> Stiffness
> Volkmann’s ischaemic contracture
> Heterotopic calcification
> Mal-union (cubitus valgus/varus)
What causes a coronoid avulsion fracture?
Avulsion by brachialis muscle
What are carpal fractures usually caused by?
- Compressive loads to hyperextended wrist
- Hyperflexion
- Rotation loading against flexed wrist
Which carpal bone is most commonly fractured?
Scaphoid
Colle’s vs Smith’s fracture
- Colle’s = dorsal displacement of distal fragment
- Smith’s = volar displacement of distal fragment
Which aspects of the pelvis/proximal femur are prone to avulsion?
- Iliac crest
- ASIS
- AIIS
- Ischial tuberosity
- Symphysis
- Greater trochanter
- Lesser trochanter
Internal vs external rotation of hip
Leg at 90° anteriorly:
- Internal = move foot laterally
- External = move foot medially
What does a posterior hip dislocation look like on X-ray?
- Femoral head displaced superiorly
- Femur internally rotated –> less lesser trochanter prominence
- More greater trochanter prominence
What does an anterior hip dislocation look like on X-ray?
- Femoral head displaced superiorly
- Lesser trochanter more prominent (external rotation of femur)
Which arteries are at risk in a femoral shaft fracture?
- Superficial femoral artery
- Popliteal artery (if displaces into popliteal fossa)
