Patella Study

PA Projection

1. Patient in prone position;
2. Tip of the foot supported in the table (patella parallel with the plane of the IP).

Central ray perpendicular to the middle of the popliteal area.

Evaluation Criteria:

• Patella superimposed by the femur;
• No rotation;
• Visualization of the knee joint;
• Appropriate exposure values (visualization of the all bony trabeculation and soft tissue).

Lateral projection

1. Patient in the lateral recumbent position;
2. Flex the knee at 30º.

Central ray perpendicular to the middle of pattelofemoral joint.

Evaluation Criteria:

• Knee flexed 0º;
• Patellofemural joint open;
• Patella in profile;
• Appropriate exposure values (visualization of the all bony trabeculation and soft tissue).

Tangential Projection

1. Patient in supine position;
2. Flex the knee at 30º, 60º or 90º;
3. Ask to patient hold the IP.

Central ray angled 15º (knee flexed 30º), 20º (knee flexed 60º) or 25º (knee flexed 90º) cephalic and tangential to the patella.

Evaluation Criteria:

• Patella in profile;
• Patellofemural joint open;
• Appropriate exposure values (visualization of the all bony trabeculation and soft tissue).