Knee Flashcards
At what degree of flexion is the patella demonstrated on the patellar surface?
20 degrees
At what degree of flexion is the patella demonstrated between the patellar surface and the intercondylar fossa?
30-70 degrees
At what degree of flexion is the patella demonstrated within the intercondylar fossa?
90 degrees
What is the positional error if the medial femoral condyle is larger and the tibia superimposes more than 1/2 of the fibular head?
External rotation
What is the positional error if the lateral femoral condyle is larger and the tibia superimposed less than 1/2 of the fibular head?
Internal rotation
What is patellar subluxation?
The patella may be situated more laterally than normal
What tube angulation should be used for a patient thickness of 18cm or less?
5 degrees caudal
What tube angulation should be used for a patient thickness of 19-24cm
Perpendicular (no angle)
What tube angulation should be used for a patient thickness of 25cm or more?
5 degrees cephalad
How do you identify if the cephalad angle was too great?
Fibular head is foreshortened and demonstrated more than .5” distal to plateau
How do you identify if the causes angle was too great?
Fibular head will be elongated and demonstrated less than .5” distal to plateau
What compartment of the knee is narrowed with a valgus deformity?
Lateral compartment
What compartment of the knee is narrowed with a varus deformity?
Medial compartment
How do you identify a properly positioned lateral knee?
•tibia superimposes 1/2 of fib head
•anterior and posterior margins of the medial and lateral femoral condyles are aligned
•open patella femoral joint space
What degree of flexion is needed for a lateral knee?
10-15
20-30
?
Where are the anterior and posterior suprapatellar fat pads located?
Anterior to the patellar surface of the distal femur
What are the anterior and posterior suprapatellar fat pads seperated by?
Suprapatellar bursa
Lateral knee
What is the positional error when the medial condyle (adductor tubercle) is posterior to lateral condyle, and the fibular head is superimposed on the tibia?
Internal rotation
Lateral knee
What is the positional error when the medial condyle (adductor tubercle) is anterior to the lateral condyle and the fibular head is free of tibial superimposition?
External rotation
Lateral knee
What degree of angulation should be used for a patient with a wide pelvis?
7 degrees cephalad
Lateral knee
What degree of angulation should be used for a patient with an average pelvis?
5 degrees cephalad
What projection was completed if the head, neck and shaft of the fibular are aligned with the anterior edge of the tibia and the medial femoral condyle is in profile?
AP oblique - external rotation
What projection was completed if the lateral femoral condyle is in profile and the fibular head is seen free of superimposition?
AP oblique - internal rotation
What is the positional error of a medial oblique knee if the tibia partially superimposed the fibular head?
Insufficient internal rotation
What is the positional error of a medial oblique knee if there is excessive femoral condyle superimposition?
Excessive internal rotation
What is the positional error of a lateral oblique knee if the fibular head is demonstrated without full tibial superimposition?
Insufficient external rotation
What is the positional error of a lateral oblique knee where the fibular head is not aligned with the anterior edge of the tibia but seen posterior?
Excessive external rotation
What tangential projection of the patella demonstrates the lateral femoral condyle slightly higher than the medial condyle?
Inferosuperior projection
What tangential projection of the patella demonstrates the femoral condyles at equal height?
Settegast method
What is the accurate amount of knee flexion for the tangential patella inferosuperior projection?
45 degrees
What is the accurate amount of knee flexion for a tangential patella projection with the Settegast method?
90 degrees
What is the positional error if the femoral condyles are equal height for the inferosuperior tangential patella?
Knee was flexed more than 45 degrees
