Introduction to musculoskeletal radiology (banks)

Question 1

Answer 1

Question 2

Several diagnostic modalities can be used to evaluate musculoskeletal disorders:

Answer 2

X- Rays, CT and DXA* use ionizing radiation*.
Ultrasound uses high frequency ultrasound waves.
Nuclear Medicine uses gamma rays from isotopes.
MRI uses high magnetic field strength.

• DXA (Dual energy X-ray Absorptiometry) uses a small dose of ionizing radiation to measure bone loss.
• Ionizing radiation and gamma rays - form of high energy capable of removing electrons from an atom or molecule of

Question 3

General Trauma Workup

Answer 3

Start with X-rays, 3 views of the area of concern should be obtained: anterior, lateral and oblique.

To improve sensitivity for subtle/occult fractures, consider contralateral radiographs or more advanced imaging such as a CT or MRI.

Question 4

identify and mechanism

Answer 4

Clavicle fracture
Mechanism of fracture: direct blow to the clavicle
Fracture is most common in the middle portion of the clavicle (65-80%)

Question 5

Identify ligaments

Answer 5

Question 6

Identify and mechanism

Answer 6

Mechanism of AC joint injury:
Fall onto the shoulder
Falling on the outstretched hand (FOOSH)

Classification of AC joint injury:
Types 1-3: Treatment is medical
Types 4-6: Rare/Treatment is surgical

Question 7

Answer 7

Normal Shoulder
The humeral head sits in the middle of the scapula, over the glenoid process.

If the humeral head is under the coracoid process, this is an anterior shoulder dislocation

If the humeral head is under the acromial process this is a posterior shoulder dislocation.

Question 8

Answer 8

Anterior shoulder dislocation

Question 9

Answer 9

Posterior shoulder dislocation
Light bulb sign: internally rotates with posterior dislocation
Trough sign: fx of medial anterior head of humerus, see 2 parallel cortical lines medially indicates a compression fx

Question 10

Answer 10

Calcification in the supraspinatus tendon

Question 11

Answer 11

Degenerative joint disease (DJD)

shoulder impingement with disruption of suprasinatus tendon

Question 12

Answer 12

Humeral shaft fracture

Medial displacement of proximal fragment by the pulling force of the pectoralis major and teres major muscles.

Question 13

Elbow fractures

Answer 13

Most common area in adults is a fracture in radial head/neck
Second most common is in the olecranon process
Mechanism: F O O S H, or direct fall on flexed elbow
Can be associated with dislocation

Question 14

Answer 14

Elbow pain; FOOSH

anterior displacement of the anterior fat and and visualization of the posterior fat pad indicates elbow joint effusion. In a setting of trauma, the cause would be fracture

Question 15

Answer 15

Fat pad “sail sign”

Question 16

Answer 16

Olecranon process fracture

Question 17

Answer 17

elbow posterior fracture dislocation

Question 18

X- Ray of the Hand and Wrist

Answer 18

The most commonly injured body part is the hand
The hand has 27 bones and 29 major joints
In most cases, X-Rays are sufficient
8% of hand fractures are multiple, so look for additional fractures

Question 19

Answer 19

Distal Radius fracture

1/6th of all fractures in the emergency department are distal radial fractures
Mechanism: F O O S H

Question 20

Answer 20

Scaphoid fracture 
Most commonly  fractured carpal bone, anatomic “snuff box”
Location:
Waist: 65%
Proximal: 25%
Distal third: 10%
Incidence of avascular  necrosis (AVN):
13 – 40% (post traumatic)
Almost all in proximal pole to due to limited blood supply

Question 21

Answer 21

scaphoid fractures

Question 22

Answer 22

Boxer fracture

a distal metacarpal fracture that usually invokes the fish metacarpal

Question 23

Answer 23

Proximal femoral fractures

1. femoral neck
2. intertrochanteric
3. subtrochanteric

Question 24

Answer 24

Femoral neck fracture

Complication: A V N is more common with intracapsular fractures than with extracapsular fractures

Question 25

Answer 25

occult fracture

X- ray insensitive for hip fracture
Especially in elderly with osteoporosis
Fracture incomplete or nondisplaced
10% of femoral fractures are occult on X-ray, CT is 85% sensitive, and MRI is almost 100% sensitive

Question 26

Answer 26

occult fracture in the hip

Question 27

Answer 27

proximal femoral intertrochanteric fractures

Question 28

Answer 28

supracondylar fracture

Question 29

Answer 29

Intercondylar fracture of the knee

Question 30

Answer 30

knee dislocation

Question 31

Answer 31

tibial plateau fracture

Question 32

Answer 32

MCL calcification (pellegrini-sieda)
calcification is secondary to old trauma to MCL and/or medical femoral condyle

Question 33

Answer 33

(anterior cruciate ligament) ACL tear causes displacement of the tibia anteriorly (anterior drawer sign)

Question 34

Answer 34

ACL tear, MRI of the knee;

Question 35

Answer 35

posterior cruciate ligament PCL tear causes displacement of the tibia posteriorly (posterior drawer sign)

Question 36

Answer 36

Question 37

Answer 37

calcaneal spur

Question 38

Answer 38

fhl: flexor hallucis longus
a: Achilles tendon

Black arrows: Plantar aponeurosis, rises from the calcaneus. Plantar fasciitis- inflammation of the plantar aponeurosis (fascia).

Question 39

Answer 39

sesamoid/bone

flexor hallucis longus tendon inserts on the plantar aspect of the base of the distal phalanx of the great toe, after traveling between the two sesamoids

Question 40

Answer 40

achilles tendon tear

Question 41

Answer 41

achilles tendon tear

Question 42

compare different radiographic modalities

Answer 42