An AP knee projection obtained with the central ray angled too cephalically demonstrates
1)symmetrical femoral condyles.
2)a foreshortened fibular head.
3)the fibular head at a position less than 0.5 inch (1 cm) distal to the tibial plateau.
4)a narrowed or closed femorotibial joint space.
A) 1, 3, and 4 only
B) 1, 2, and 4 only
C) 2 and 3 only
D) 1, 2, 3, and 4

Question

Quizplus · Accepted Answer

When the central ray is angled too cephalically in an AP knee projection, it causes foreshortening of the fibular head (option 2) and narrowing or closure of the femorotibial joint space (option 4). Symmetrical femoral condyles (option 1) and the position of the fibular head less than 0.5 inch (1 cm) distal to the tibial plateau (option 3) are not affected by the cephalic angulation of the central ray in an AP knee projection. Therefore, the correct choice is B.

An AP Knee Projection Obtained with the Central Ray Angled