Normal knee plain radiographs: AP, lateral, oblique, and sunrise views

(A) Normal adult knee in the frontal AP projection.
(B) Normal adult knee seen in lateral projection. Lateral radiograph of a normal adult knee. The positioning is nearly perfect, as judged by the superimposition of the femoral condyles. The slight concavity (small arrow) is the lateral (condylar) sulcus. The normal lucency of the suprapatellar recess (asterisk) identifies the deep surface of the quadriceps tendon (arrow). The infrapatellar space (thick arrows) is also normally lucent.
(C) Normal adult knee seen in externally oblique projection.
(D) Normal adult knee seen in internally rotated oblique projection.
(E) Axial ("sunrise") view of the normal patella. The lateral femoral condyle (arrowheads) and the long lateral facet (dashed arrows) of the patella are less steep than their medial counterparts.