Injuries Of The Knee And Patella

Question 1

What is the anatomy of the knee?
(6)

Answer 1

Femur

Tibia and fibula

Patella

Cartilage that covers the articular surface of each bone

Ligaments that hold the bone together (elastic bands of tissue)

Tendons that attach a muscle to the bone (tough cords)

Question 2

What are common knee injuries?
(5)

Answer 2

Fractures

Dislocation

Ligament and tendon injuries- tear, sprain

Joint problems- cartilage/meniscus damage, arthritis

Bone diseases

Question 3

How do we get knee fractures?

Answer 3

Direct blow- RTC, fall, impact

Question 4

Which parts of the knee need to be on an x-ray after a knee fracture?
(3)

Answer 4

Distal femur

Proximal tibia/fibula

Patella

Question 5

What x-ray projections should be done for a knee fracture?
(2)

Answer 5

AP

HBL (for demonstration of lipohaemarthrosis)

Question 6

What is the largest sesamoid bone in the body?

Answer 6

The patella

Question 7

Label the AP knee:

Answer 7

Question 8

What are the features of the patella?
(3)

Answer 8

It’s the largest sesamoid bone in the body

It protects the anterior of the knee

It acts as an insertion for the quadricep tendon and a fulcrum for extension

Question 9

What can patella fractures look like?

Answer 9

Question 10

What projections would we do for a patella fracture?
(2)

Answer 10

AP

Lateral

Question 11

Which projection WON’T we do for a patella fracture?

Answer 11

Skyline

Question 12

How do we x-ray for patella fractures?
(4)

Answer 12

AP and lateral

Don’t ask the patient to move/flex their knee

Consider a HBL

Depending on the extent of injury, they can be surgically fixed

Question 13

How do we tend to get distal femur fractures?
(2)

Answer 13

Blunt trauma- usually in young people, e.g. RTC

Low energy causing a fall- usually in the elderly

Question 14

What are the features of the tibial plateau?
(3)

Answer 14

It’s concave

There’s 2- medial plateau and lateral plateau

It’s central (non-articular)

Question 15

How does a tibial plateau fracture look like?

Answer 15

Question 16

How do knee fractures get fixed?
(2)

Answer 16

Femoral nail

Tibial plate and screws

Question 17

What does a fibula head fracture look like?
(2)

Answer 17

Bony ring type structure

Normally breaks in more than 1 place

Question 18

How should we perform an x-ray for a fibula head fracture?
(3)

Answer 18

Perform an x-ray of the rest of the tibia/fibula if painful

Ankle up images

AP and lateral

Question 19

Which projections should we use for a dislocated knee joint?
(2)

Answer 19

AP

HBL

Question 20

What does a dislocated knee joint look like?

Answer 20

Question 21

If the x-ray request forms says ? Bony involvement, should we x-ray?

Answer 21

Yes

Question 22

What projections should we use when x-raying for ligament and tendon injuries?
(2)

Answer 22

AP

Turned lateral

Question 23

What joint pathologies can we get?
(2)

Answer 23

Cartilage damage

Meniscus damage

Question 24

What projections should we do when x-raying for joint pathologies?
(3)

Answer 24

AP

Lateral

HBL if trauma is recent

Question 25

What is osteoarthritis?

Answer 25

When the protective cartilage breaks down

Question 26

What are the symptoms of osteoarthritis? (2)

Answer 26

Bony growths/spurs can appear Pain and swelling

Question 27

How does osteoarthritis look like?

Answer 27

Question 28

What projections should we use when looking at osteoarthritis? (2)

Answer 28

AP weight bearing Lateral turned

Question 29

What projections should we use on a knee with knee replacements/plates? (2)

Answer 29

AP- centred lower than normal to get the full prosthesis Lateral- also centred lower than normal