In a true lateral knee radiograph, which feature indicates proper positioning?

In a true lateral knee radiograph, which feature indicates proper positioning?

• A. Superimposition of the femoral condyles
• B. Alignment of the femur and patella
• C. Malleoli on the same transverse plane
• D. Superimposition of the tibia and fibula

Answer: (B)

For a true lateral knee view, the key sign is that the thigh and the patella line up in the same plane, showing no rotation. When the femur and patella are aligned, the knee is truly lateral, allowing the patella to project in profile against the femur and the distal femoral condyles to appear properly superimposed. This alignment confirms the view is taken with the knee in true lateral and the patellofemoral joint visible without rotational distortion. Other cues can help support a lateral view, but they’re not as direct a single indicator of proper rotation. For example, the tibia and fibula are often overlapped in a lateral knee, but rotation can sometimes still produce this overlap with an imperfect view. The malleoli relate to the ankle, not the knee, so they don’t indicate knee positioning.

For a true lateral knee view, the key sign is that the thigh and the patella line up in the same plane, showing no rotation. When the femur and patella are aligned, the knee is truly lateral, allowing the patella to project in profile against the femur and the distal femoral condyles to appear properly superimposed. This alignment confirms the view is taken with the knee in true lateral and the patellofemoral joint visible without rotational distortion.

Other cues can help support a lateral view, but they’re not as direct a single indicator of proper rotation. For example, the tibia and fibula are often overlapped in a lateral knee, but rotation can sometimes still produce this overlap with an imperfect view. The malleoli relate to the ankle, not the knee, so they don’t indicate knee positioning.