Lateral knee (mediolateral)

Patient position

• Turned onto the affected side (right side down); the other leg brought forward over it or behind it.
• Knee flexed 20–30° (no more if a patella fracture is possible).
• Femoral epicondyles directly superimposed, perpendicular to the IR; patella perpendicular to the IR.

Centering

2.5 cm (1″) distal to the medial epicondyle.

Central ray

Angled 5–7° cephalic (the medial condyle projects lower); 0° for a horizontal-beam trauma lateral.

Source-to-image distance

100 cm (40″).

Image evaluation

• Femoral condyles superimposed
• Patellofemoral joint space open
• Fibular head slightly overlapped by the tibia
• Knee flexed 20–30°