Calcaneous

Question 1

AP Calcaneus: Clinical indications:

Answer 1

Pathologies or fractures with medial or lateral displacement.

Question 2

AP Calcaneus: Technical factors:

Answer 2

40"
8x10" lengthwise
No grid
Analog 70 plus or minus 5 kV range
Digital 70-75 kV range

Question 3

AP Calcaneus: Pt position:

Answer 3

Place pt supine or seated on table with leg fully extended.

Question 4

AP Calcaneus: Part position:

Answer 4

Center and align ankle joint to CR and to portion of IR being exposed.
Dorsiflex foot so that plantar surface is near perpendicular to IR.

Question 5

AP Calcaneus: CR:

Answer 5

• Direct CR to base of third metatarsal to emerge at a level just distal to lateral malleolus.
• Angle CR 40º cephalad from long axis of foot (which also would be 40º from vertical if long axis of foot is perpendicular to IR.)

Question 6

AP Calcaneus: CR angulation must be increased if:

Answer 6

long axis of plantar surface of foot is not perpendicular to IR.

Question 7

AP Calcaneus: Anatomy demonstrated:

Answer 7

Entire calcaneus should be visualized from tuberosity posteriorly to talocalcaneal joint anteriorly.

Question 8

AP Calcaneus: Evaluation criteria (position)

Answer 8

• No rotation; a portion of the sustentaculum tali should appear in profile medially.
• With the foot in proper 90º flexion, correct alignment and angulation of CR are evidenced by open talocalcaneal joint space, no distortion of the calcaneal tuberosity, and adequate elongation of the calcaneus.

Question 9

AP Calcaneus: Exposure:

Answer 9

Optimal density and contrast with no motion demonstrate sharp bony margins and trabecular markings and at least fairly visualize talocalcaneal joint without overexposing distal tuberosity area.

Question 10

Lateral-Mediolateral projection of the Calcaneus: Clinical indications:

Answer 10

Bony lesions involving calcaneus, talus, and talocalcaneal joint.
Demonstrate extent and alignment of fractures.

Question 11

Lateral-Mediolateral projection of the Calcaneus: Technical factors:

Answer 11

40" SID
8x10" IR lengthwise
No grid
Analog 60 plus or minus 5 kV range.
Digital 60-70 kV range

Question 12

Lateral-Mediolateral projection of the Calcaneus: Pt position:

Answer 12

Place pt in lateral recumbent position, affected side down. Provide a pillow for pt’s head. Flex knee of affect limb about 45º; place opposite leg behind injured limb.

Question 13

Lateral-Mediolateral projection of the Calcaneus: Part position:

Answer 13

• Center calcaneus to CR and to unmasked portion of IR, with long axis of foot parallel to plane of IR.
• Place support under knee and leg as needed to place plantar surface perpendicular to IR.
• Position ankle and foot for a true lateral, which places the lateral malleolus about 1 cm posterior to the medial malleolus.
• Dorsiflex foot so that plantar surface is at right angle to leg.

Question 14

Lateral-Mediolateral projection of the Calcaneus: CR:

Answer 14

Cr perpendicular to IR, directed to a point 1 inch inferior to medial malleolus.

Question 15

Lateral-Mediolateral projection of the Calcaneus: Evaluation criteria: Anatomy demonstrated:

Answer 15

Calcaneus is demonstrated in profile with talus and distal tibia-fibula demonstrated superiorly and navicular and open joint space of the calcaneus and cuboid demonstrated distally.

Question 16

Lateral-Mediolateral projection of the Calcaneus: Evaluation criteria: Position:

Answer 16

No rotation as evidenced by superimposed superior portions of the talus, open talocalcaneal joint, and lateral malleolus superimposed over posterior half of the tibia and talus.
Tarsal sinus and calcaneocuboid joint space should appear open.
Four-sided collimation should include ankle joint proximally and talonavicular joint and base of fifth metatarsal anteriorly.

Question 17

Lateral-Mediolateral projection of the Calcaneus: Evaluation criteria: Exposure:

Answer 17

Optimal exposure visualizes some soft tissue and more dense portions of calcaneus and talus. Outline of the distal fibula should be faintly visible through the talus.