Foot and Ankle Surgery Practice Questions

Q: Avascular necrosis is commoner in which of the following bones?

Talus. **Explanation:** The **Talus** is highly susceptible to Avascular Necrosis (AVN) due to its unique anatomical and vascular characteristics. Approximately **60% of the talus is covered by articular cartilage**, leaving a limited surface area for nutrient arteries to enter. Furthermore, it lacks any muscular or tendinous attachments. Its blood supply is **retrograde** (flowing from the neck to the body), primarily derived from the artery of the tarsal canal (branch of the posterior tibial artery). Fractures of the talar neck frequently disrupt this precarious blood supply, leading to a high incidence of AVN (Hawkins’ Classification). **Analysis of Options:** * **Cuboid & Calcaneum:** These bones have a robust, multi-directional blood supply and are surrounded by significant soft tissue and muscular attachments. AVN in these bones is extremely rare. * **Navicular:** While the navicular can undergo AVN (known as **Kohler’s disease** in children or **Mueller-Weiss syndrome** in adults), it is statistically less common than post-traumatic AVN of the talus. **Clinical Pearls for NEET-PG:** * **Hawkins’ Sign:** A subchondral radiolucent line seen on an X-ray of the talus 6–8 weeks post-fracture. It indicates intact vascularity (active resorption of bone) and is a **good prognostic sign** (rules out AVN). * **Other bones prone to AVN:** Scaphoid (proximal pole), Femoral head, and Capitate. These all share the common feature of **retrograde blood flow**. * **Most common site of AVN in the body:** Head of the Femur.

Q: Which mechanism of injury is most commonly associated with ankle joint injuries?

Inversion of the foot. **Explanation:** **1. Why Inversion is Correct:** Ankle sprains are among the most common musculoskeletal injuries, and approximately **85% of all ankle injuries** result from an **inversion mechanism**. This typically occurs when the foot is in a position of plantarflexion and the ankle rolls inward. The primary anatomical reason for this is the relative weakness of the lateral ligament complex compared to the medial (Deltoid) ligament. In an inversion injury, the **Anterior Talofibular Ligament (ATFL)** is the first and most common ligament to be torn, followed by the Calcaneofibular Ligament (CFL). **2. Analysis of Incorrect Options:** * **B. Eversion of the foot:** This mechanism is much less common because the **Deltoid ligament** on the medial side is extremely strong and thick. Eversion injuries often result in an avulsion fracture of the medial malleolus rather than a ligamentous tear. * **C. Internal rotation:** While internal rotation can occur during trauma, it is rarely the primary isolated mechanism for common ankle sprains. * **D. External rotation:** This mechanism is specifically associated with **syndesmotic injuries** (High Ankle Sprains) and certain types of Weber/Lauge-Hansen fractures (e.g., Supination-External Rotation), but it is statistically less frequent than simple inversion sprains. **3. Clinical Pearls for NEET-PG:** * **Most common ligament injured:** Anterior Talofibular Ligament (ATFL) – "Always Torn First." * **Ottawa Ankle Rules:** Used to determine if an X-ray is required (tenderness at the posterior edge of malleoli or inability to bear weight). * **Lauge-Hansen Classification:** The most common type of ankle fracture is the **Supination-External Rotation (SER)** injury. * **Treatment:** Most inversion sprains are managed conservatively with the **RICE** protocol (Rest, Ice, Compression, Elevation).

Q: What is the treatment for this condition?

Surgical exploration and repair. ***Surgical exploration and repair*** - **Surgical repair** is the gold standard treatment for **acute Achilles tendon rupture**, especially in active patients, providing superior functional outcomes and lower re-rupture rates. - **Direct suturing** of the torn tendon ends restores **anatomical continuity** and allows for optimal healing with proper rehabilitation protocols. *Physiotherapy* - **Conservative management** with physiotherapy alone results in **higher re-rupture rates** (10-15%) and inferior functional outcomes compared to surgical repair. - While suitable for **elderly** or **sedentary patients**, it leads to permanent **weakness** and **reduced plantarflexion strength** in active individuals. *Arthrodesis of ankle and subtalar joint* - **Joint fusion** is reserved for **end-stage degenerative conditions** or severe **post-traumatic arthritis**, not acute tendon ruptures. - This procedure results in **permanent loss of motion** and is inappropriate for a condition that can be successfully repaired with preserved function. *Tendon transfer* - **Tendon transfers** (like FHL or peroneus longus) are indicated for **chronic Achilles ruptures** (>6 weeks old) where primary repair is not feasible due to **tendon retraction** and **gap formation**. - In acute ruptures, the **tendon ends** can be approximated directly, making transfer procedures unnecessarily complex and associated with donor site morbidity.

Q: Bohler's angle is measured in fractures involving which tarsal bone?

Calcaneum. **Explanation:** **Bohler’s Angle** (also known as the Tuber-joint angle) is a crucial radiological parameter used in the assessment of **Calcaneum fractures**. It is formed by the intersection of two lines: 1. A line drawn from the highest point of the anterior process to the highest point of the posterior facet. 2. A line drawn from the highest point of the posterior facet to the highest point of the calcaneal tuberosity. The **normal range is 25° to 40°**. In intra-articular calcaneal fractures (the most common tarsal bone fracture), the angle **decreases** or may even become negative, signifying a collapse of the posterior facet and loss of calcaneal height. **Analysis of Incorrect Options:** * **Talus:** Fractures here are assessed using Hawkins’ classification. The key radiological sign is "Hawkins’ Sign" (subchondral lucency indicating intact vascularity). * **Navicular:** Fractures are often stress-related or part of midfoot injuries (Kohler’s disease in children). Bohler’s angle does not involve this bone. * **Cuboid:** Fractures (like "Nutcracker fractures") are rare and evaluated for lateral column shortening, not by Bohler’s angle. **NEET-PG High-Yield Pearls:** * **Gissane’s Angle:** Also called the "Critical Angle," it is the other major angle measured in calcaneal fractures (Normal: 120°–145°). It *increases* in fractures. * **Mondor’s Sign:** Ecchymosis extending to the sole of the foot, pathognomonic for calcaneal fracture. * **Associated Injuries:** Always rule out **compression fractures of the Lumbar spine (L1)** in patients with calcaneal fractures (Don Juan Syndrome/Lover's High Leap fracture) due to axial loading. * **Gold Standard Investigation:** CT scan (Broden’s views are the specific X-ray views).

Q: Amputation marked at level of 'C' is:

Lisfranc. ***Lisfranc*** - **Lisfranc amputation** occurs at the **tarsometatarsal joint level**, which corresponds to level 'C' in standard anatomical diagrams of foot amputation levels. - This amputation preserves the **midfoot** including the navicular, cuboid, and cuneiform bones, allowing better weight-bearing function. *Chopart* - **Chopart amputation** is performed at the **midtarsal joint** (calcaneocuboid and talonavicular joints), which is more **proximal** than level 'C'. - This level preserves the **calcaneus and talus** but removes the midfoot and forefoot structures. *Symes* - **Symes amputation** is an **ankle-level** amputation that removes the foot while preserving the **heel pad** for end-bearing. - This is the most **proximal** foot amputation level, well above the level 'C' marking. *Boyd* - **Boyd amputation** involves **ankle arthrodesis** with **calcaneal-tibial fusion**, creating an end-bearing stump. - This is also an **ankle-level** procedure, more proximal than the tarsometatarsal joint level indicated by 'C'.

Q: A 32-year-old athlete presents with posterior heel pain. Which of the following could be a differential diagnosis?

All of the above. **Explanation:** Posterior heel pain in an athlete is a common clinical presentation, typically involving the **Achilles tendon complex** or its associated bursae. The correct answer is **All of the above** because these three conditions share a similar anatomical location and clinical presentation. 1. **Achilles Tendinopathy:** This is the most common cause of posterior heel pain in athletes. It can be *insertional* (at the calcaneal attachment) or *non-insertional* (2–6 cm proximal to the insertion). It presents with localized pain and stiffness that worsens with activity. 2. **Achilles Tendon Rupture:** This is an acute injury, often described by the patient as a "pop" or a feeling of being "kicked in the heel." It results in immediate pain, a palpable gap, and a positive **Thompson (Simmonds) test**. 3. **Retrocalcaneal Bursitis:** This involves inflammation of the bursa located between the anterior aspect of the Achilles tendon and the posterior calcaneus. It is often associated with **Haglund’s deformity** (a prominent posterosuperior calcaneal tuberosity). **NEET-PG High-Yield Pearls:** * **Thompson Test:** Squeezing the calf fails to produce plantarflexion; diagnostic for complete Achilles rupture. * **Haglund’s Triad:** Retrocalcaneal bursitis, Achilles tendinosis, and a prominent calcaneal bursal projection. * **Imaging:** MRI is the gold standard for soft tissue assessment, though Ultrasound is a cost-effective initial tool for identifying tears or tendinosis. * **Treatment:** Most chronic tendinopathies respond to eccentric loading exercises, while acute ruptures in athletes may require surgical repair.

Q: What is the optimal position of the ankle to prevent ankylosis?

Slight plantar flexion. The goal of preventing ankylosis (joint stiffness/fusion) is to maintain the joint in a position of function. For the ankle, the optimal position is slight plantar flexion (approx. 5–10°). **Why Slight Plantar Flexion?** In the neutral (90°) position, the wider anterior part of the trochlea of the talus fits tightly into the mortise formed by the tibia and fibula. This provides maximum bony stability but places significant tension on the collateral ligaments and the Achilles tendon. Maintaining a position of slight plantar flexion relaxes the posterior compartment muscles and allows for a more natural gait during recovery. If the joint were to fuse in this position, it allows the patient to wear shoes with a slight heel, which facilitates the "toe-off" phase of walking. **Analysis of Incorrect Options:** * **B. Slight plantar extension:** This is a confusing term; "extension" of the ankle is technically dorsiflexion. Regardless, excessive extension is not functional. * **C. Slight dorsiflexion:** This position puts the Achilles tendon under constant stretch and makes the joint "locked" and unstable for weight-bearing if ankylosis occurs. It also makes walking in standard footwear difficult. * **D. Slight inversion:** Inversion or eversion are non-neutral coronal plane deviations. Ankylosis in inversion leads to painful weight-bearing on the lateral border of the foot (varus deformity). **High-Yield NEET-PG Pearls:** * **Position of Function (Ankle):** 5–10° Plantar flexion. * **Stability:** The ankle is most stable in **dorsiflexion** (talus is wedged into the mortise) and most mobile/unstable in **plantar flexion**. * **Ligament Injury:** Most ankle sprains occur in **plantar flexion and inversion**, commonly affecting the **Anterior Talofibular Ligament (ATFL)**—the weakest ligament of the ankle.

Q: The Hawkins Classification is used for which type of fracture?

Talus fracture. The **Hawkins Classification** is the gold-standard system used to categorize **talar neck fractures**. It is clinically significant because it predicts the risk of **Avascular Necrosis (AVN)** of the talus, which has a tenuous retrograde blood supply (primarily via the artery of the tarsal canal). ### **Classification Breakdown:** * **Type I:** Undisplaced fracture (AVN risk: 0–15%). * **Type II:** Displaced fracture with subluxation/dislocation of the **subtalar joint** (AVN risk: 20–50%). * **Type III:** Displaced fracture with dislocation of both **subtalar and tibiotalar joints** (AVN risk: nearly 100%). * **Type IV:** Type III plus dislocation of the **talonavicular joint** (Canale and Kelly modification). ### **Analysis of Incorrect Options:** * **A. Tibial fracture:** Commonly classified by the **Schatzker** system (for tibial plateau) or **Lauge-Hansen/Danis-Weber** (for distal tibia/malleoli). * **B. Calcaneum fracture:** The most common classification used is the **Sanders Classification** (based on CT findings) or **Essex-Lopresti**. * **C. Radius head fracture:** Categorized using the **Mason Classification**. ### **High-Yield Clinical Pearls for NEET-PG:** * **Hawkins Sign:** A subcortical radiolucency (osteopenia) seen on X-ray 6–8 weeks post-injury. Its presence indicates intact vascularity (no AVN), while its absence suggests AVN. * **Aviator’s Astragalus:** Another name for talus fractures, historically caused by sudden dorsiflexion during plane crashes. * **Blood Supply:** The **Posterior Tibial Artery** (via the artery of the tarsal canal) provides the major blood supply to the talar body.

Question 1

Avascular necrosis is commoner in which of the following bones?

Accepted Answer

Talus

Answer

Cuboid

Answer

Calcaneum

Answer

Navicular

Question 2

Which mechanism of injury is most commonly associated with ankle joint injuries?

Accepted Answer

Inversion of the foot

Answer

Eversion of the foot

Answer

Internal rotation of the foot

Answer

External rotation of the foot

Question 3

What is the treatment for this condition?

Accepted Answer

Surgical exploration and repair

Answer

Physiotherapy

Answer

Arthrodesis of ankle and subtalar joint

Answer

Tendon transfer

Question 4

Bohler's angle is measured in fractures involving which tarsal bone?

Accepted Answer

Calcaneum

Answer

Talus

Answer

Navicular

Answer

Cuboid

Question 5

A 45-year-old male presents with foot pain after an injury. What is the mechanism of injury associated with the pathology seen in this X-ray?

Accepted Answer

Inversion of the foot producing tension on the peroneus brevis tendon

Answer

Forcible inversion of the foot in plantar flexion, such as in a dancer's injury

Answer

Fall while climbing stairs or falling from a height

Answer

A direct blow

Question 6

Hallux valgus is associated with all of the following except:

Accepted Answer

An exostosis on the medial side of the head of the first metatarsal

Answer

A bunion

Answer

Osteoarthritis of the metatarsophalangeal joint

Answer

Overriding or under-riding of the second toe by the third

Question 7

Amputation marked at level of 'C' is:

Accepted Answer

Lisfranc

Answer

Chopart

Answer

Symes

Answer

Boyd

Question 8

A 32-year-old athlete presents with posterior heel pain. Which of the following could be a differential diagnosis?

Accepted Answer

All of the above

Answer

Achilles tendinopathy

Answer

Tendon rupture

Answer

Retrocalcaneal bursitis

Question 9

What is the optimal position of the ankle to prevent ankylosis?

Accepted Answer

Slight plantar flexion

Answer

Slight plantar extension

Answer

Slight dorsiflexion

Answer

Slight inversion

Question 10

The Hawkins Classification is used for which type of fracture?

Accepted Answer

Talus fracture

Answer

Tibial fracture

Answer

Calcaneum fracture

Answer

Radius head fracture

Foot and Ankle Surgery — MCQs

Foot and Ankle Surgery — MCQs

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