Knee

Question 1

standard projections for Knee

Answer 1

AP
Latera
Skyline/Axial

Question 2

centre for AP knee

Answer 2

Centre 1cm distal to apex of patella-middle of joint

Question 3

Patient position for AP knee

Answer 3

Pt supine with both legs extended
Imaging plate is behind the affected knee
Femoral condyles equidistant to imaging plate
Leg is slightly rotated inward (internally rotate) to place knee in a true AP position.

Question 4

Criteria for AP Knee

Answer 4

Regional anatomy included – distal
femur and proximal tibia and fibula,
including soft tissue
>Femorotibial joint space open
>Patella superimposed on midline of
femur

Question 5

what is the patient position for intercondylar knee

Answer 5

Pt supine- Flex affected knee by 40-45 degrees
Ensure no rotation of the leg internally /externally
Get the imaging plate as close to the posterior side of the knee as possible- place
sponges/other support needed

Question 6

Criteria for intercondylar Knee

Answer 6

Intercondylar fossa open (not
superimposed by apex of patella)
>Femorotibial joint space open
>Intercondylar eminence separated
and in the center of the intercondylar
fossa
>No rotation- Femoral and tibial
condyles appear symmetrical

Question 7

centring for lateral knee

Answer 7

2cm distal to medial epicondyles

Question 8

patient position for lateral knee

Answer 8

> Pt to roll onto affected side, to superimpose the femoral epicondyles
Flex knee 20-30deg
Place a sponge under the ankle so the long axis of the tif/fib is parallel to Imaging plate
Other leg can be either behind or in front of affected leg
Angle central ray 5deg cephalad (to head)

Question 9

Criteria for lateral knee

Answer 9

Femoropatellar joint space open
>Femoral condyles should appear
superimposed
>Patella in profile
>Fibular head only slightly
superimposed over tibia

Question 10

centring for skyline knee view

Answer 10

Centre to apex of patella

Question 11

patient position for Skyline knee

Answer 11

> Pt supine with affected leg extended
Bend affected knee 45deg
Imaging plate resting on mid-thigh and tilted so perpendicular to central ray
Pt can hold the imaging plate in position for a supine position
Angle central ray so it’s parallel to the patella and travelling through the joint space

Question 12

criteria for skyline knee

Answer 12

Base and apex of patella
superimposed
>Femoropatellar joint space open
>Patella in profile
>Femoral condyles appear
symmetrical

Question 13

how to determine what is the medial and lateral epicondyles for the femur

Answer 13

Using the adductor tubercle (on the medial condyle ) and lateral femoral notch

if medial to far out = externally rotate
if lateral to far out = internally rotate

Question 14

what is osteoarthritis

Answer 14

• narrowing space between bones as cartilage goes away
• seen on weightbearing

Question 15

valgus deformity

Answer 15

legs angled inwards

Question 16

Bi-partite and tripartite

Answer 16

ossification failure on patella
BI = 2 parts
TRI =3 parts

Question 17

Osgood schlatter

Answer 17

patella tendon pulls of growth plate

Question 18

how would you angle the beam for a lateral knee

Answer 18

5 degrees cephalad

Question 19

how would you angle the beam for a horizontal lateralmedial knee

Answer 19

5 Degrees caudal (down)

Question 20

how to fix this

Answer 20

internally rotate

Question 21

how to fix this

Answer 21

externally rotate