Anatomy of Calcaneus and Tibia

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Questions and Answers

What is the correct angling direction of the central ray (CR) for the plantodorsal axial projection of the calcaneus?

40˚ from vertical (correct)

60˚ from vertical

30˚ from vertical

50˚ from vertical

When performing an axial calcaneus view, how should the patient's foot be positioned?

Turned inwards towards the other foot

Dorsiflexed so plantar surface is near perpendicular to IR (correct)

Plantar flexed with toes pointing downward

In a neutral position

What is an essential consideration when performing procedures on geriatric patients?

They do not require any special handling

Always position them standing

Use standard positioning without modification

Check for signs of hip fracture (correct)

To ensure optimal evaluation of the plantodorsal calcaneus projection, which criterion must be met?

Entire calcaneus visualized with no rotation Signup and view all the answers

Why should the ankle be elevated on sandbags during the dorsoplantar axial projection?

To better visualize the ankle joint Signup and view all the answers

What is the proper angle for the CR during a dorsoplantar axial calcaneus view?

40˚ to the long axis of the foot Signup and view all the answers

In the lateral calcaneus position, where should the CR be directed?

1 inch inferior to the medial malleolus Signup and view all the answers

Which evaluation criterion is essential for the lateral calcaneus view?

Calcaneus and talus visualized without rotation Signup and view all the answers

What is the proper positioning for a patient during the AP ankle view?

Patient supine with leg fully extended Signup and view all the answers

What structure is best visualized in an AP mortise ankle view?

Ankle joint space Signup and view all the answers

Which structure is referred to as the 'support for the talus'?

Sustentaculum Tali Signup and view all the answers

What is visualized laterally on an axial projection of the calcaneus?

Peroneal Trochlea Signup and view all the answers

How many articulations are present in the calcaneus?

3 Signup and view all the answers

Which of the following bones articulates with the calcaneus?

Talus Signup and view all the answers

Which of the following statements about the projections for calcaneus and ankle radiography is correct?

Routine projections include both axial and lateral views. Signup and view all the answers

Which prominence is part of the fibula anatomy?

Lateral Malleolus Signup and view all the answers

The medial proximal aspect of the calcaneus is best described by which structure?

Sustentaculum Tali Signup and view all the answers

Which projection is specifically used for calcaneal assessment?

Special Axial view Signup and view all the answers

What joint is formed by the Talus and Calcaneus?

Subtalar (Talocalcaneal) joint Signup and view all the answers

What is the name of the deep depression between the Posterior and Middle articular facets of the Calcaneus?

Calcaneal sulcus Signup and view all the answers

Which part of the Tibia is known for bearing weight?

Body (shaft) Signup and view all the answers

What shape is the distal end of the Tibia?

Pyramid Signup and view all the answers

What structure is formed by the inferior portions of the Tibia and Fibula?

Mortise Signup and view all the answers

Which statement about the Fibula is true?

It articulates with the Talus distally. Signup and view all the answers

Which view demonstrates the concave inferior surface of the Tibia?

Axial view Signup and view all the answers

What key anatomical feature does the Lateral Malleolus provide?

Articulation with the Talus Signup and view all the answers

What is the positioning requirement for the AP projection during open reduction surgery of the ankle?

Patient supine with legs fully extended and foot in natural position Signup and view all the answers

Which projection is specifically useful for evaluating fractures of the distal fibula?

Oblique 45˚ Ankle Signup and view all the answers

During the lateral ankle positioning, how should the foot be positioned in relation to the leg?

In a natural position as far as tolerable Signup and view all the answers

What is the correct central ray (CR) direction for the lateral projection of the ankle?

Perpendicular to the IR, directed at the medial malleolus Signup and view all the answers

Which evaluation criterion is NOT required in the lateral ankle projection?

Distal ⅓ of tibia and fibula demonstrated Signup and view all the answers

For AP stress projections, what should be demonstrated to adequately evaluate ankle joint integrity?

Distal aspect of tibia and fibula demonstrated Signup and view all the answers

In what position should the patient be for the lateral weight-bearing ankle projection?

Lateral recumbent position with legs fully extended Signup and view all the answers

Study Notes

Calcaneus

The calcaneus is also known as the os calcis.
It articulates with the talus and cuboid bones.
The talus and calcaneus form the subtalar or talocalcaneal joint.
The calcaneus has 3 articular facets: posterior, middle, and anterior.
The calcaneal sulcus is a deep depression located between the posterior and middle articular facets.
The peroneal trochlea or trochlear process is visualized laterally on an axial projection.
The sustentaculum tali, meaning "support for the talus," is located on the medial proximal aspect of the calcaneus.

Tibia

The tibia is the weight-bearing bone of the lower leg.
It consists of three parts: proximal end, body (shaft), and distal end.
The distal end of the tibia terminates in a short, pyramid-shaped process called the medial malleolus, easily palpated on the medial side of the ankle.
The lateral aspect of the distal tibia forms a flattened notch called the fibular notch, where the distal fibula articulates.
The anterior tubercle is an expanded process at the distal anterior and lateral tibia, articulating with the superolateral talus.
The tibial plafond is the distal tibial joint surface forming the roof of the ankle mortise joint.

Fibula

The fibula is smaller than the tibia and located laterally and posteriorly to it.
It articulates with the tibia proximally and distally, and the talus distally.
The fibula consists of three parts: proximal extremity, body (shaft), and distal extremity.
The distal extremity forms the lateral malleolus.

Ankle Joint

The ankle joint is formed by the tibia, fibula, and talus.
The inferior portions of the tibia and fibula form the mortise, a three-sided opening that accommodates the superior talus.
The mortise is not fully visualized on a true AP projection, requiring a 15° internal rotation of the leg (mortise position).
The posterior half of the distal tibia superimposes the fibula on a lateral view.
An axial view demonstrates the concave inferior surface of the tibia, the tibial plafond.

Calcaneus Radiographic Projections

Plantodorsal Axial:
- CR angled 40° from vertical directed to the base of the third metatarsal.
- Visualizes the entire calcaneus without rotation.
Dorsoplantar Axial:
- Patient in prone position with the ankle elevated on sandbags.
- CR directed to the midpoint of the IR, emerging at the level of the base of the 5th metatarsal.
- CR angled 40° caudally to the long axis of the foot.
Lateral (Mediolateral):
- Patient in lateral recumbent position with the knee flexed 45°.
- CR perpendicular to the IR, directed 1 inch inferior to the medial malleolus.

Ankle Radiographic Projections

AP:
- CR midway between the malleoli.
- Demonstrates distal ⅓ of tibia and fibula, proximal ½ of metatarsals, and the medial and superior aspects of the ankle joint.
AP Mortise:
- Leg and foot internally rotated 15-20°.
- CR perpendicular to IR, midway between the malleoli.
- Visualizes the entire ankle mortise.
Lateral (Mediolateral):
- Patient in lateral recumbent position with the knee flexed 45°.
- CR perpendicular to the IR, directed to the medial malleolus.
- Visualizes the entire talus and calcaneus, with the lateral malleolus superimposed over the posterior half of the tibia.
Oblique 45°:
- Leg and foot rotated medially 45°.
- CR perpendicular to IR, midway between the malleoli.
- Visualizes the distal tibiofibular joint, distal ⅓ of tibia and fibula, and proximal ½ of metatarsals.
AP Stress:
- Performed with inversion and eversion stress to assess ligamentous stability.
AP and Lateral Weight-Bearing:
- Performed with the patient standing for weight-bearing evaluation.

Special Patient Considerations

Pediatric: Parents can assist with positioning.
Geriatric: Handle with care and assess for hip fracture.
Cast Conversions: Utilize a cast conversion chart.

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Description

This quiz explores the anatomical features of the calcaneus and tibia, two crucial bones in the lower extremity. Key aspects include their articulations, individual characteristics, and relevant anatomical landmarks. Test your knowledge on the structures and functions of these bones.