Femur

Question 1

What are the clinical indications for an x-ray of the femur?

Answer 1

• Mid- and distal femur, including knee joint for detection and evaluation of fractures and/or bone lesions.
• If the site of interest is in the area of the proximal femur, a unilateral hip routine or pelvis is recommended.

Question 2

How should the patient be positioned if only the knee is included on the image receptor?

Answer 2

• Rotate the patient’s limb 5° medially to place it in true AP position.
• Put the lower end of the image receptor 5 cm below the knee joint.

Question 2

What is the direction of the central ray for an antero-posterior projection of the femur?

Answer 2

Vertical 90° to the image receptor.

Question 2

What is the centering point for an antero-posterior projection of the femur?

Answer 2

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

Question 2

How should the patient be positioned if only the hip is included on the image receptor?

Answer 2

• Place the upper end of the image receptor at the level of the anterior superior iliac spine (ASIS).
• Rotate the limb internally 10° to 15° to place the femoral neck in profile.

Question 3

What should be shown in the AP image of the femur for the joint nearest the pathologic condition or site of injury?

Answer 3

Most of the femur and the joint nearest to the pathologic condition or site of injury; a second projection of the other joint is recommended.

Question 4

How should the femoral neck appear in the AP image of the proximal femur?

Answer 4

The femoral neck should not be foreshortened.

Question 5

Should the lesser trochanter be visible beyond the medial border of the femur in the AP image of the proximal femur?

Answer 5

The lesser trochanter should not be seen beyond the medial border of the femur, or only a very small portion should be visible.

Question 5

How should the knee appear in the AP image of the distal femur?

Answer 5

• There should be no knee rotation;
• Femoral and tibial condyles should appear symmetric in size and shape with the outline of the patella slightly toward the medial side of the femur.

Question 6

What should be included in the AP image of the femur if an orthopedic appliance is present?

Answer 6

The orthopedic appliance should be included in its entirety.

Question 6

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

Answer 6

• Lie the patient on the affected side,
• Flex the knee of the injured side approximately 45°,
• 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 7

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

Answer 7

• Adjust the image receptor to include the knee joint.
• The 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 8

Where is the centering point for the lateral projection of the femur?

Answer 8

The medial aspect of the femur to the midpoint of the image receptor

Question 9

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

Answer 9

Vertical at 90° to the image receptor.