5. R. knee radiograph, AP projection

In this projection the patella is superimposed on the distal end of the femur, with the center of the patellar shadow lying approximately at the level of the adductor tubercle when the leg is fully extended at the knee. The radiolucent space between the femoral and tibial condyles on both the medial and lateral sides of the knee represents the apposition of the articular cartilages of the condyles with each other and with the partially intervening meniscus.