tib fib

Question 1

What are the clinical indications for an X-ray of the tibia and fibula (lower leg)?

Answer 1

Pathologies involving fractures, foreign bodies, or lesions of the bone.

Question 2

What are the basic projections for the tibia and fibula?

Answer 2

a. Antero-posterior projection
b. Lateral projection

Question 3

What equipment and technical factors are required for an antero-posterior projection of the tibia and fibula?

Answer 3

• 35 x 43 cm image receptor lengthwise or diagonal
• Sheet of lead rubber
• Foam pads
• Lead protective waist apron or gonad shield
• FFD 100 cm
• Non-grid (unless lower leg measures >10 cm)

Question 4

How should the patient be positioned for an antero-posterior projection of the tibia and fibula?

Answer 4

• Place patient in the supine position.
• Provide a pillow for the patient’s head.
• Leg should be fully extended.
• Adjust pelvis, knee, and leg into true AP with no rotation.
• Place sandbag against foot if needed for stabilization, and dorsiflex foot to 90° to lower leg if possible.

Question 5

What should be done if the patient’s leg is too long to fit on one image receptor for an antero-posterior projection?

Answer 5

• Place the leg diagonally (corner to corner) on one 35 × 43 cm image receptor to ensure that both joints are included.

Question 5

What is the centring point and direction of the central ray for an antero-posterior projection of the tibia and fibula?

Answer 5

Centering point:
Anterior aspect on the middle of the tibia and fibula (midway between the ankle and knee joints).

Direction of central ray:
Vertical at 90° to the image receptor.

Question 6

How should the patient be positioned for a lateral projection of the tibia and fibula?

Answer 6

• From the antero-posterior position, the patient lies on the affected side with the hip and knee slightly flexed.
• Malleoli superimposed and patella at right angles to the image receptor.
• Place radiolucent pads under the knees and toes.
• Collimate beam and apply radiation protection using the lead protective waist apron or gonad shield.

Question 7

What are the evaluation criteria for an AP projection of the tibia and fibula?

Answer 7

• Entire tibia and fibula must include ankle and knee joints on this projection (or two if needed).
• No rotation as evidenced by demonstration of femoral and tibial condyles in profile with intercondylar eminence centered within intercondylar fossa.
• No motion is present, as evidenced by sharp cortical margins and trabecular patterns.
  Contrast and density (brightness) should be optimum to visualize soft tissue and bony trabeculae.

Question 8

What anatomy should be demonstrated in a lateral projection of the tibia and fibula?

Answer 8

• Entire tibia and fibula must include ankle and knee joints on this projection (or two if needed).
• Exception is alternative routine on follow-up examinations.

Question 9

What are the evaluation criteria for the position in a lateral projection of the tibia and fibula?

Answer 9

• True lateral of tibia and fibula without rotation demonstrates tibial tuberosity in profile, a portion of the proximal head of the fibula superimposed by the tibia, and outlines of the distal fibula seen through posterior half of the tibia.
• Posterior borders of femoral condyles should appear superimposed. Collimation to area of interest.

Question 10

What are the evaluation criteria for exposure in a lateral projection of the tibia and fibula?

Answer 10

• No motion is present, as evidenced by sharp cortical margins and trabecular patterns.
• Correct use of the anode heel effect results in near-equal density at both ends of the image.
• Contrast and density (brightness) should be optimum to visualize soft tissue and bony trabecular markings.