Knee

Question 1

Which view is best for viewing patellar positioning?

Answer 1

lateral view

Question 2

Which view is best for looking at the intercondylar fossa?

Answer 2

PA axial “tunnel” view

Question 3

What can you see with the tangential view of the patellofemoral joint?

Answer 3

articular surfaces of the patella femoral joint and relation of the patella to the distal femur

Question 4

What is the sulcus angle? What is normal?

Answer 4

formed by joining two lines from the highest points on the medial and lateral condyles, which meet at the lowest point on the intercondylar groove
- normal is 138 +/- 6 deg

Question 5

What does an increased sulcus angle indicate? Decreased sulcus angle?

Answer 5

increased sulcus angle - shallow patellar groove = increased risk for patellar dislocation

decreased sulcus angle - deep patellar groove

Question 6

What is the congruence angle? What is normal?

Answer 6

describes the relationship between the patella and the trochlear articular surface of the femur
- normal = -6 deg

Question 7

What congruence angle value is associated with lateral subluxation of patella?

Answer 7

+ 16 deg

Question 8

Ottawa Knee Rules

Answer 8

• age 55 or older OR
• isolated tenderness of patella OR
• tenderness of head of fibula OR
• inability to flex knee to 90 deg OR
• inability to weight bear both immediately and in ED for 4 steps

Question 9

chronic knee pain - initial imaging adult or child >/= 5 y/o

Answer 9

radiography knee

Question 10

chronic knee pain - next imaging procedure, adult or child >/= 5 y/o, initial knee radiograph negative or demonstrates joint effusion

Answer 10

MRI

Question 11

chronic knee pain - next imaging procedure, adult or child >/= 5 y/o, initial knee radiographs demonstrates osteochondritis dissecans (OCD), loose bodies, or history of cartilage or meniscal repair

Answer 11

MRI

Question 12

acute trauma to the knee - initial imaging adult or child >/= 5 y/o, fall or acute twisting trauma to knee, no focal tenderness, no effusion, able to walk

Answer 12

No imaging is recommended, however
- radiography may be appropriate

Question 13

acute trauma to the knee - initial imaging adult or child >/= 5 y/o, fall or acute twisting trauma to knee, 1 or more of the following: focal tenderness, effusion, inability to bear weight

Answer 13

radiography

Question 14

What is focal tenderness?

Answer 14

tenderness over patella, head of fibula, and inability to bear weight
- Ottawa Knee Rules

Question 15

acute trauma to the knee - next study, adult or skeletally mature child, fall or acute twisting trauma, no fx seen on radiographs, suspect occult fx or internal derangement

Answer 15

MRI

Question 16

Acutely limping child up to age 5 - initial imaging, acute limp, nonlocalized symptoms, no concern for infection

Answer 16

radiography tibia/fibula

Question 17

Acutely limping child up to age 5 - initial imaging, acute limp, pain, localized symptoms, no concern for infection

Answer 17

radiography lower extremity area of interest