DPM Foot & Ankle Anatomy 3 — Questions and Answers
Question 1: The anterior talofibular ligament (ATFL) resists which primary motion at the ankle?
- Eversion and dorsiflexion
- Inversion and plantarflexion (Correct answer)
- External rotation and eversion
- Dorsiflexion and abduction
Correct answer: Inversion and plantarflexion
The ATFL is the weakest lateral ankle ligament and primarily resists anterior talar displacement combined with inversion and plantarflexion.
Question 2: Which nerve provides sensory innervation to the web space between the first and second toes (dorsal aspect)?
- Medial plantar nerve
- Deep peroneal nerve (Correct answer)
- Superficial peroneal nerve
- Saphenous nerve
Correct answer: Deep peroneal nerve
The deep peroneal nerve provides sensory innervation to the first dorsal web space (between hallux and second toe) and motor supply to the extensor digitorum brevis.
Question 3: The sustentaculum tali is a shelf-like projection of which bone?
- Talus
- Navicular
- Calcaneus (Correct answer)
- Tibia
Correct answer: Calcaneus
The sustentaculum tali is a medial shelf projection of the calcaneus that supports the talus and provides a groove for the flexor hallucis longus tendon.
Question 4: Which artery is the primary blood supply to the talus, entering through the tarsal canal?
- Posterior tibial artery
- Peroneal artery
- Artery of the tarsal canal (from posterior tibial) (Correct answer)
- Dorsalis pedis artery
Correct answer: Artery of the tarsal canal (from posterior tibial)
The artery of the tarsal canal, a branch of the posterior tibial artery, is the dominant blood supply to the talar body, explaining avascular necrosis risk after fractures.
Question 5: The plantar fascia originates from which specific calcaneal landmark?
- Posterior calcaneal tuberosity
- Medial process of calcaneal tuberosity (Correct answer)
- Lateral process of calcaneal tuberosity
- Anterior calcaneal process
Correct answer: Medial process of calcaneal tuberosity
The plantar fascia (aponeurosis) originates primarily from the medial process of the calcaneal tuberosity and fans out to the five metatarsal heads.
Question 6: Which muscle is responsible for inversion of the foot and is innervated by the deep peroneal nerve?
- Tibialis posterior
- Peroneus longus
- Tibialis anterior (Correct answer)
- Extensor hallucis longus
Correct answer: Tibialis anterior
Tibialis anterior inverts and dorsiflexes the foot and is innervated by the deep peroneal nerve; tibialis posterior also inverts but is innervated by the tibial nerve.
Question 7: At the ankle mortise, the fibula contributes what percentage of the lateral tibiotalar surface?
- 10%
- 25% (Correct answer)
- 40%
- 50%
Correct answer: 25%
The fibula contributes approximately 25% of the tibiotalar contact surface, providing lateral stability to the ankle mortise.
DPM Foot & Ankle Anatomy 3
The anterior talofibular ligament (ATFL) resists which primary motion at the ankle?