Femur lateral

Question 1

How should the patient be positioned for a lateral projection of the femur?

Answer 1

• Lie the patient on the affected side.
• Flex the knee of the injured side approximately 45°, and align the femur to the midline of the x-ray couch or image receptor.
• Place the unaffected leg behind the affected leg to prevent over-rotation.

Question 2

How should the image receptor be adjusted for a lateral projection of the femur?

Answer 2

• Adjust the image receptor to include the knee joint (lower image receptor margin should be approximately 5 cm below the knee joint).
• A second x-ray examination should be done to include the proximal femur and hip if the whole femur didn’t fit on one image receptor.

Question 3

What is the centering point for a lateral projection of the femur?

Answer 3

Medial aspect of the femur to the midpoint of the image receptor.

Question 4

What is the direction of the central ray for a lateral projection of the femur?

Answer 4

Vertical at 90° to the image receptor.

Question 5

What should be done if the patient has severe trauma and cannot lie on the injured side for a lateral projection of the femur?

Answer 5

• Place support under the affected leg and knee and support the foot and ankle in a true AP position.
• Place the image receptor on edge against the medial aspect of the thigh to include the knee, with a horizontal x-ray beam directed from the lateral side.

Question 6

What are the evaluation criteria for a lateral femur image?

Answer 6

• Evidence of proper collimation.

*Most of the femur and the joint nearest to the pathologic condition or site of injury (a second radiograph of the other end of the femur is recommended).
* Any orthopedic appliance in its entirety.
* Soft tissue and bony trabecular detail.

Question 7

What should be clearly shown in a lateral femur image with the knee included?

Answer 7

• Superimposed anterior surface of the femoral condyles.
• Patella in profile.
• Open patellofemoral space.
• Inferior surface of the femoral condyles not superimposed because of divergent rays.

Question 8

Trauma Lateromedial Projection

Answer 8

• Place support under affected leg and knee
  and support foot and ankle in true AP
  position.
• Place image receptor on edge against medial
  aspect of thigh to include knee, with
  horizontal x-ray beam directed from lateral
  side

Question 9

What should be clearly shown in a lateral femur image with the hip included?

Answer 9

• Opposite thigh not over the proximal femur and hip joint.
• Greater trochanter superimposed over the distal femoral neck.
• Lesser trochanter visible on the medial aspect.