Knee Xray

CPT 73564-26 (Professional component only. Xrays must not have already been interpretted.)

CPT 73564-TC (Technical component only.)

• Demonstrates: femorotibial articulation
• Helpful for: Knee Arthritis, Tibial Plateau Fracture, Distal Femur Fracture,

Position: Standing with knees flexed 45° with grid in front of knees

Beam directed 10° caudal from the horizontal plane through the knee joint.

• Demonstrates: femorotibial articulation.
• Helpful for:Knee Arthritis, Tibial Plateau Fracture, Distal Femur Fracture,

Position: supine with cassette under knee and femoral condyles parelll to cassette.

Beam directed to point 1-2cm distal to the patella.

• Demonstrates: femorotibial articulation, patellofemoral articulation. Femoral condyles should be superimposed.
• Helpful for:Knee Arthritis, Tibial Plateau Fracture, Distal Femur Fracture, Patellar Fracture, Patellofemoral Arthritis

Position: lateral with affected side down and flexed 30° at the knee. The contralateral leg is shifted posteriorly out of the way.

Beam directed at knee joint with 5°cephalad angulation.

• Demonstrates: posterior aspect of femoral condyles, intercondylar notch, intercondylar eminence of tibia
• Helpful for:Tibial Eminence Fx, Tibial Spine Fx, Distal Femur Fracture,

Position: prone, knee flexed 40°

Beam directed caudally toward the knee joint at a 40° angle from vertical.

• Demonstrates: tangential view of patella; femoropatellar articulation
• Helpful for: Patellofemoral Arthritis, Patellar Fracture, Patellofemoral Pain.

Position: Prone; knee flexed 115°

Beam directed toward patella with 15° cephalad angulation

• Demonstrates: patellofemoral articulation. Centrial ridge of patella should lie at or medial to the bisector of the trochlear angle. 
• Helpful for: Evaluating patellar tilt. Not very sensitive, Patellofemoral Arthritis, Patellar Fracture, Patellofemoral Pain.

Position:supine knee flexed 45°;

Beam directed caudally toward patella at a 60° angle (30° from the horixontal plane).

(Merchant A, JBJS 1974; 56A:1391)

• Insall-Salvati Ratio
• Blackburne-Peel Ratio: <0.8=patella baja, >1.2=patella alta.

Image= lateral view of  patient with patellar tendon rupture demonstrating patella alta.

• Frank ED, Merrill's Atlas of Radiographic Positioning and Procedures, 2007