Knee (AP Obliques), Patella, and Intercondylar Fossa Assessment

What is the entry point for the CR for both AP oblique projections of the knee?

1/2” inferior to the apex of the patella

If the pt’s ASIS to tabletop is 18cm, how will you direct your CR for the AP oblique projection of the knee with lateral rotation?

3-5 degrees caudad

For the AP oblique projection of the knee with lateral rotation, how is the extremity positioned

Externally rotated 45 degrees

For the AP oblique projection of the knee with lateral rotation, how should the fibula be visualized with respect to the tibia?

Superimposed over the lateral half of the tibia

For the AP oblique projection of the knee with lateral rotation, how should the patella appear?

With the margin of the patella projected slightly beyond the edge of the lateral femoral condyle

For the AP projection of the knee with medial rotation, if the ASIS to tabletop measures 25cm, how will you direct your CR?

3-5 degrees cephalad

For the AP oblique projection of the knee with medial rotation, how is the extremity positioned?

Medially rotated 45 degrees

For the AP oblique projection of the knee with medial rotation, how should the fibula be visualized with respect to the tibia?

Separated at the proximal articulation

For the AP oblique projection of the knee with medial rotation, how should the patella appear?

With the margin of the patella projected slightly beyond the edge of the medial femoral condyle

For the PA axial projection of the intercondylar fossa (Camp-Coventry method), how is the central ray directed with the knees flexed 40 degrees

Angled 40 degrees, perpendicular to the long axis of the lower leg

For the Camp-Coventry method, where does the central ray enter and exit?

Enters the popliteal fossa and exits at the patellar apex

How should the intercondylar fossa by demonstrated on the image in a properly positioned Camp-Coventry method?

open

How should the apex of the patella appear in a properly positioned Camp-Coventry method?

Not superimposing the intercondylar fossa

How do you assess for rotation on a PA axial projection of the intercondylar fossa (Camp-Coventry method)

slight tibiofibular overlap and centered intercondylar eminence

for the tangential projection of the patella (Settegast method) what is the typical angulation?

15-20 degrees cephalad

By using an angle for the tangential projection of the patella (Settegast method), we are trying to maintain the relationship of the CR so that its perpendicular to which structure?

perpendicular to the joint space between the patella and the femoral condyles

The tangential projection of the patella (Settegast method) is very helpful for identifying which type of patellar fracture?

Vertical fracture of the patella

How should the patella be demonstrated in a properly positioned tangential projection of the patella (Settegast method)?

In profile

How should the patellofemoral joint be demonstrated in a properly positioned tangential projection of the patella (Settegast method)? Open