Knee And Shin Imaging

Question 1

How do we check alignment of an AP knee? (3)

Answer 1

1. Patella should be slightly lateral to midline
2. The fibular should be slightly superimposed on tibia
3. Femoral and Tib condyles should be symmetrical

Question 2

How do we check alignment on a lateral knee x ray?

Answer 2

1. Femoral condyles superimposed
2. Adductor tubercle not visible
3. Fibula head should only slightly superimpose on the tibia
4. Plane of patella should be perpendicular
5. Tib fem joint spaces open

Question 3

What does Blumensaat’s line show us?

Answer 3

Height of patella - can indicate quad or patella tendon rupture depending on height changes

Question 4

On a lateral knee x ray, The distance from the inferior pole of the patella to the tibial tubercle should be what?

Answer 4

1.1 of the vertical patella height

Question 5

What is a fabella?

Answer 5

Accessory sesamoid bone in the lateral Gastroc head

Question 6

Why might you get a horizontal beam x ray of the knee?

Answer 6

To look for a lipohaemarthrosis, which can indicate intra articular fracture

Question 7

What is a Segond fracture?

Answer 7

An Avulsion fragment of the lateral tibial plateau

Question 8

What two injuries correlate with a Segond fracture?

Answer 8

1. ACL rupture
2. Meniscal tear

Question 9

What is a patellar sleeve fracture and management ?

Answer 9

An Avulsion injury at the inferior pole of the patella

Needs surgical management

Question 10

What is osteochondritis dessicans?

Answer 10

Small segment of bone begins to seperate from its surrounding region due to lack of blood supply

Can occur as a subacute injury after subschondral bone bruising

Question 11

How do we tell the difference between a knee latera and knee cross table view?

Answer 11

The knee is flexed in a lateral

Question 12

Why might you get a knee oblique view ?

Answer 12

1. Subtle tibial plateau fractures
2. Medial sided patella Avulsion fracture post dislocation