Lecture 13: Lower Extremity part 5 (ankle joint)

Question 1

1) What type of joint is the ankle joint?
2) Which bone is weight bearing? What else does it do? What does the non-weight bearing bone do?
3) What form the malleolar “mortise” with trochlea of the talus (talar dome)?

Answer 1

1) Hinge synovial joint
2) Tibia is weight bearing, medial stability via medial malleolus; fibula = lateral stability via lateral malleolus.
3) Tibia and fibula

Question 2

1) Fibula via _______________ contributes _______ stability to mortise [of ankle]
2) When is the ankle most stable? Why?

Answer 2

1) lateral malleolus; lateral
2) During dorsiflexion; wide anterior trochlea moves posterior, pushes tib-fib apart

Question 3

When is the ankle joint the most unstable?

Answer 3

During plantar flexion, while the narrower posterior trochlear moves anterior and is looser in mortise

Question 4

Inversion injury can result in what?

Answer 4

Ligament injury or fracture of lateral and/or medial malleolus

Question 5

What 3 ligaments are found on the lateral aspect of the foot?

Answer 5

Anterior and posterior talofibular ligament, calcaneofibular ligament

Question 6

What area is commonly injured with inversion injury (“ankle sprain”)?

Answer 6

Lateral aspect[’s 3 ligaments]: Anterior and posterior talofibular ligament, calcaneofibular ligament

Question 7

What does the deltoid ligament of the medial ankle do?

Answer 7

Same thing as the 3 lateral ligaments

Question 8

Define Acquired pes planus

Answer 8

Flat feet [that aren’t congenital]

Question 9

Loss of longitudinal arch can occur because of what 3 things?

Answer 9

1) TP/TA tendons
2) Spring ligament
3) Plantar aponeurosis: plantar fascia

Question 10

What is the subtalar joint also called?

Answer 10

Talocalcaneal

Question 11

What is the calcaneocuboid and talonavicular joint also called?

Answer 11

Transverse tarsal joint

Question 12

Long plantar ligament is deep to what?

Answer 12

Plantar aponeurosis

Question 13

1) The fibularis longus tendon inserts where?
2) What ligament runs from posterior to anterior on the bottom of the foot?
3) What ligament attaches to both the tibia, fibula, and the bottom of the midfoot?

Answer 13

1) 1st metatarsal
2) Long plantar ligament
3) Tibialis posterior

Question 14

Based on force vectors, the distal fibula bares ~_____% of weight

Answer 14

15%

Question 15

What 2 things are a part of the weight bearing axis of the foot?

Answer 15

Tibia and talus

Question 16

1) The weight bearing axis is transmitted posteriorly to the _____________ bone and anteriorly to the ________ of the foot… …..sesamoids of 1st MT and head of 2nd MT….then shared with heads of MT 3-4-5

Answer 16

Calcaneus; ball of the foot

Question 17

1) What form the framework of the longitudinal arch of the foot?
2) What provide support?

Answer 17

1) Bones
2) Fascia, ligaments, and tendon

Question 18

What condition should be considered in any patient with diabetes and unilateral swelling of the lower extremity and/or foot?

Answer 18

Charcot foot [diabetic condition]

Question 19

Bony destruction, fragmentation, joint subluxation and bony remodeling are considered radiographic hallmarks of what disease?

Answer 19

Charcot foot

Question 20

1) What is Hallux valgus and painful bunion?
2) Give a differential diagnosis for this

Answer 20

1) Lateral or valgus drift of first ray; prominent medial MTP
2) DDX gout