Osteology (Part 3): Calcaneus

Question 1

Calcaneus

Answer 1

• Largest bone in the foot
• Forms the heel
• Length > width

Question 2

Calcaneus angulation

Answer 2

• Long axis is directed superiorly and laterally
• Superior angulation is referred to as calcaneal pitch
• ~ 30 - 35⁰ between long axis of talus and calcaneus

Question 3

Structures of calcaneal superior surface

Answer 3

• Anterior/middle/posterior facet of calcaneus (anterior/middle/posterior talar facet)
• Calcaneal sulcus (sulcus calcanei)

Question 4

Anterior/middle facet of calcaneus (anterior/middle talar facet)

Answer 4

• Concave facets located on the anterior 1/3 of superior surface
• Articulates with anterior and middle facets of the talus
• Anterior is the smallest facet
• Middle is most medial facet, rest on sustentaculum tali

Question 5

Posterior facet of calcaneus (posterior talar facet)

Answer 5

• Middle 1/3 of superior surface
• Steep inclination
• Convex
• Articulates with the posterior facet of talus
• Larger than anterior and medial

Question 6

Calcaneal sulcus (sulcus calcanei)

Answer 6

• Anterior to posterior facet of calcaneus
• Located on the anterior 1/3 of superior surface
• Oriented anterolaterally
• Aligns with sulcus tali to form the sinus tarsi
• Forms inferior aspect
• More wide laterally

Question 7

Posterior 1/3 of superior surface

Answer 7

• Kager (pre-Achilles) fat pad is located superior

Question 8

Medial calcaneal surface structures

Answer 8

• Sustentaculum tali

Question 9

Sustentaculum tali

Answer 9

• Medial projection on calcaneus

- Ligament attachment; pulley for FHL

Question 10

Lateral calcaneal structures

Answer 10

• Peroneal trochlea (tubercle)
• Retrotrochlear eminence
• Peroneal spine

Question 11

Peroneal trochlea (tubercle)

Answer 11

• Projection on lateral surface
• Attachment of inferior fibular retinaculum
• Separates tendons of fibularis longus and brevis
• Groove for fibularis longus (below)
• Groove for fibularis brevis (above)

Question 12

Retrotrochlear eminence

Answer 12

• Posterior to peroneal tubercle

- Peroneus quartus can insert here (if so it is usually prominent)

Question 13

Peroneal spine

Answer 13

• Superior to retrotrochlear eminence

- Attachment of calcaneofibular ligament

Question 14

Anterior calcaneal surface structures

Answer 14

• Articular facet for cuboid

- Anterior process of calcaneus

Question 15

Articular facet for cuboid

Answer 15

• Articulates with cuboid
• Saddle shaped
• Concave superior to inferior
• Convex medial to lateral

Question 16

Anterior process of calcaneus

Answer 16

• Junction of anterior, superior and lateral surfaces
• Projects over cuboid
• Visible on lateral radiograph

Question 17

Inferior calcaneal surface structures

Answer 17

• Calcaneal tubercle (anterior calcaneal tuberosity)
• Calcaneal tuberosity (posterior calcaneal tuberosity)
• Trigonum plantare
• Coronoid fossa

Question 18

Calcaneal tubercle (anterior calcaneal tuberosity)

Answer 18

• Attachment of short plantar ligament (plantar calcaneocuboid)

Question 19

Calcaneal tuberosity (posterior calcaneal tuberosity)

Answer 19

• Large inferior projection
• Located posteriorly
• Weight-bearing during gait
• Site of muscle attachment
• Medial tubercle or process (larger than lateral)
• Lateral tubercle or process

Question 20

Medial tubercle or process (posterior calcaneal tuberosity)

Answer 20

• Site of heel spurs

Question 21

Trigonum plantare

Answer 21

• Area between calcaneal tubercle and calcaneal tuberosity
• Triangular shaped
• Muscle and ligament attachment

Question 22

Coronoid fossa

Answer 22

• Between calcaneal tubercle and sustentaculum tali
• Part of spring ligament attaches here
• Beak (coronoid process) of cuboid approximates this fossa

Question 23

Posterior surface of calcaneus

Answer 23

• Superior 1/3 (Trigonum Achilleum)
• Middle 1/3
• Inferior 1/3

Question 24

Superior 1/3 (Trigonum Achilleum) of posterior surface of calcaneus

Answer 24

• Smooth

- Deep retrocalcaneal bursa located here

Question 25

Middle 1/3 of posterior surface of calcaneus

Answer 25

- Rough area | - Achilles tendon insertion

Question 26

Inferior 1/3 of posterior surface of calcaneus

Answer 26

- Covered by fatty heel pad | - Weight-bearing

Question 27

Sinus tarsi formed by

Answer 27

- Sulcus tali | - Sulcus calcanei

Question 28

Attachments in the sinus tarsi

Answer 28

- Extensor digitorum/hallucis brevis - Intermediate and medial roots of frondiform ligament (stem of inferior extensor retinaculum) - Cervical ligament - Bifurcate ligament (calcaneonavicular and calcaneocuboid ligaments) - Interosseous talocalcaneal ligament

Question 29

Sinus tarsi

Answer 29

- Trumpet shaped - Lateral part is wide, medial is narrow - Lateral opening is immediately anterior to lateral malleolus

Question 30

Tarsal canal (canalis tarsi)

Answer 30

- Medial end of sinus tarsi

Question 31

Blood supply of calcaneus

Answer 31

- Medial/lateral calcaneal arteries - Anastomosis between medial/lateral calcaneal branches - Arteries of tarsal sinus and tarsal canal - Lateral tarsal artery - Medial/lateral plantar arteries

Question 32

Medial calcaneal arteries

Answer 32

- Branches from lateral plantar and posterior tibial arteries - Supplies posterior, medial and plantar heel

Question 33

Lateral calcaneal arteries

Answer 33

- Branches from fibular | - Supplies posterior, lateral, plantar aspect of heel

Question 34

Anastomosis between medial and lateral calcaneal branches

Answer 34

- Supplies superior posterior calcaneus

Question 35

Arteries of tarsal sinus and tarsal canal

Answer 35

- Supply anterosuperior calcaneus

Question 36

Lateral tarsal artery

Answer 36

- Supplies anterolateral calcaneus

Question 37

Medial and lateral planar arteries

Answer 37

- Supply plantar aspect