Trauma Practice Questions

Q: A 22-year-old male is admitted with a fracture of the left femur. Two days later, he becomes mildly confused, has a respiratory rate of 40/min, and a scattered petechial rash on his upper torso. Chest X-ray shows patchy alveolar opacities bilaterally. His arterial blood gas analysis is abnormal. What is the most likely diagnosis?

Fat embolism. **Explanation:** The clinical presentation of a long bone fracture (femur) followed by a **"latent period" of 24–72 hours**, respiratory distress (tachypnea), neurological symptoms (confusion), and a **petechial rash** (typically in the axilla, neck, and conjunctiva) is the classic triad of **Fat Embolism Syndrome (FES)**. 1. **Why Fat Embolism is correct:** In FES, fat globules are released from the bone marrow into the systemic circulation. These globules cause mechanical obstruction and trigger a biochemical inflammatory response (free fatty acid release), leading to endothelial damage. The "Snowstorm appearance" on Chest X-ray (patchy alveolar opacities) and hypoxemia on ABG are hallmark findings. 2. **Why other options are incorrect:** * **Pulmonary Thromboembolism:** Usually occurs later (1–2 weeks post-injury) and does not present with a petechial rash. * **Chest Contusion:** This would present immediately after trauma, not after a 2-day delay, and would be associated with direct thoracic injury. * **Cerebral Edema:** While confusion is present, it does not explain the petechial rash or the bilateral pulmonary opacities. **Clinical Pearls for NEET-PG:** * **Gurd’s Criteria:** Used for diagnosis. Major criteria include axillary/subconjunctival petechiae, hypoxemia ($PaO_2 < 60$ mmHg), and CNS depression. * **Earliest Sign:** Tachycardia and Tachypnea. * **Most Specific Sign:** Petechial rash (found in only 20–50% of cases but highly diagnostic). * **Management:** Primarily supportive (Oxygenation/Ventilation). Early stabilization of the fracture is the best preventive measure. * **Investigation of Choice:** Pulse oximetry (screening); ABG (confirmatory for hypoxemia).

Q: Growth disturbance, nonunion, elbow instability, and late ulnar nerve palsy are commonly seen in which type of fracture?

Fracture of the lateral condyle. **Explanation:** Fracture of the **lateral condyle of the humerus** is the correct answer because it is an **intra-articular fracture** that often involves the growth plate (Salter-Harris Type IV). 1. **Why it is correct:** The lateral condyle is a "fracture of necessity" (usually requiring ORIF) because the fragment is pulled by the extensor muscles, leading to displacement. * **Nonunion:** Synovial fluid inhibits callus formation, and the pull of extensors causes constant motion. * **Growth Disturbance:** Damage to the physis leads to **Cubitus Valgus** deformity. * **Late Ulnar Nerve Palsy (Tardy Ulnar Nerve Palsy):** As the cubitus valgus deformity progresses, the ulnar nerve is chronically stretched over the medial epicondyle, leading to delayed palsy years after the injury. 2. **Why other options are wrong:** * **Supracondylar Humerus:** Most common pediatric elbow fracture. Complications include Volkmann’s Ischemic Contracture and **Cubitus Varus** (Gunstock deformity), but nonunion is rare as it is extra-articular. * **Medial Condyle:** Rare injury. While it can cause ulnar nerve issues, it does not typically result in the classic triad of nonunion, cubitus valgus, and tardy palsy associated with lateral condyle fractures. * **Radial Head:** Common in adults; usually results in restricted forearm rotation (pronation/supination) rather than late ulnar nerve palsy. **Clinical Pearls for NEET-PG:** * **Milch Classification** is used for lateral condyle fractures. * **Tardy Ulnar Nerve Palsy** is most classically associated with **Lateral Condyle Nonunion**. * **Cubitus Varus** = Supracondylar fracture; **Cubitus Valgus** = Lateral condyle fracture.

Q: What is the last step in fracture healing?

Remodeling. **Explanation:** Fracture healing is a continuous biological process typically divided into four distinct histological stages. The correct answer is **Remodeling**, which represents the final and longest phase of bone repair. **1. Why Remodeling is correct:** Remodeling (Phase of Modeling) begins once the fracture has been bridged by firm bone. In this stage, the bulky clinical callus is reshaped. Osteoclasts resorb unnecessary bone (external callus), while osteoblasts lay down lamellar bone along the lines of mechanical stress (**Wolff’s Law**). This process restores the bone to its original shape and restores the medullary canal. It can take months to years to complete. **2. Why other options are incorrect:** * **A. Hematoma:** This is the **first stage** (Inflammation). It occurs within hours of injury, providing a fibrin scaffold for signaling molecules and progenitor cells. * **B. Callus formation:** This occurs in the middle stages. **Soft callus** (cartilage/fibrous tissue) is formed first, followed by **Hard callus** (woven bone), which provides initial structural stability. * **C. Consolidation:** This is the stage where the woven bone of the hard callus is transformed into mature lamellar bone. While it signifies clinical union, it precedes the final structural "fine-tuning" of remodeling. **NEET-PG High-Yield Pearls:** * **Sequence of Healing:** Hematoma → Inflammation → Soft Callus → Hard Callus → Consolidation → Remodeling. * **Primary Bone Healing:** Occurs via absolute stability (e.g., compression plating). There is **no callus formation**; healing happens via "cutting cones." * **Secondary Bone Healing:** Occurs via relative stability (e.g., intramedullary nailing or casts). It involves **callus formation**. * **Wolff’s Law:** Bone grows or remodels in response to the forces or demands placed upon it.

Q: Which nerve is most commonly involved in a fracture of the neck of the humerus?

Axillary nerve. **Explanation:** The **axillary nerve** is the correct answer because of its intimate anatomical relationship with the proximal humerus. It originates from the posterior cord of the brachial plexus (C5, C6) and winds around the **surgical neck of the humerus** through the quadrangular space, accompanied by the posterior circumflex humeral artery. Due to this proximity, any fracture involving the surgical neck or an anterior dislocation of the shoulder joint puts the axillary nerve at high risk of traction or direct injury. **Analysis of Incorrect Options:** * **A. Musculocutaneous nerve:** This nerve pierces the coracobrachialis muscle and is more commonly injured during shoulder surgeries (like the Latarjet procedure) or heavy lifting, rather than humeral neck fractures. * **B. Median nerve:** This nerve runs medially in the arm and is most commonly injured in **supracondylar fractures** of the humerus in children. * **C. Ulnar nerve:** The ulnar nerve is most vulnerable at the elbow as it passes behind the **medial epicondyle**. **NEET-PG High-Yield Pearls:** * **Axillary Nerve Injury:** Clinically presents with weakness in shoulder abduction (Deltoid paralysis) and sensory loss over the lateral aspect of the upper arm (**Regimental Badge area**). * **Radial Nerve:** Most commonly injured in **mid-shaft humerus fractures** (Holstein-Lewis fracture) as it travels in the spiral groove. * **Nerve Injury Rule of Thumb:** * Surgical Neck → Axillary Nerve * Spiral Groove (Shaft) → Radial Nerve * Supracondylar → Median Nerve (specifically AIN) * Medial Epicondyle → Ulnar Nerve

Q: A bucket handle tear occurs at the knee joint due to which of the following injuries?

Injury to the menisci. **Explanation:** A **Bucket Handle Tear** is a specific type of longitudinal, full-thickness tear of the **meniscus** (most commonly the medial meniscus). In this injury, the inner fragment of the torn meniscus displaces centrally into the intercondylar notch, while the peripheral part remains attached. This displaced fragment resembles the handle of a bucket, hence the name. **Why the correct answer is right:** * **Mechanism:** It typically occurs due to a forceful twisting (rotational) injury on a semi-flexed, weight-bearing knee. * **Clinical Presentation:** The hallmark sign is **"locking" of the knee joint**, where the patient is unable to fully extend the knee because the displaced meniscal fragment mechanically blocks the joint movement. **Why the incorrect options are wrong:** * **Medial/Lateral Collateral Ligaments (MCL/LCL):** These are extracapsular/capsular ligaments. Injuries here lead to joint instability (valgus/varus stress) and localized pain, but they do not cause "bucket handle" mechanical blocks. * **Ligamentum Patellae:** Injury to this structure (patellar tendon rupture) results in a failure of the extensor mechanism, meaning the patient cannot actively extend the knee against gravity; it does not cause a meniscal-style tear. **High-Yield Clinical Pearls for NEET-PG:** 1. **Medial vs. Lateral:** Bucket handle tears are **3 times more common in the Medial Meniscus** because it is less mobile and more firmly attached to the joint capsule. 2. **The "Unhappy Triad" (O'Donoghue):** Often tested alongside meniscal injuries; it involves injury to the **ACL, MCL, and Medial Meniscus**. 3. **Diagnosis:** **MRI** is the gold standard investigation. On MRI, the "Double PCL sign" is a classic indicator of a bucket handle tear. 4. **Treatment:** Definitive management is usually via **Arthroscopic repair** or partial meniscectomy.

Q: What is the most important sign of Volkmann's ischemia?

Stretch pain. **Explanation:** Volkmann’s Ischemia is the precursor to Volkmann’s Ischemic Contracture (VIC), resulting from untreated **Compartment Syndrome**, most commonly following a supracondylar fracture of the humerus. **Why "Stretch Pain" is the correct answer:** The hallmark of early compartment syndrome is **pain out of proportion to the injury**. Specifically, **pain on passive stretching** of the finger extensors (for the forearm) is the **earliest and most sensitive clinical sign**. This occurs because the increased intracompartmental pressure compromises microcirculation to the muscles; stretching these ischemic muscles triggers intense nociceptive signals before nerve or skin changes occur. **Analysis of Incorrect Options:** * **B. Pallor:** This is a late sign indicating severe arterial compromise. In many cases of compartment syndrome, the limb remains pink because the capillary refill may still be present. * **C. Numbness (Paresthesia):** While an important sign of nerve ischemia, it usually appears after the onset of ischemic muscle pain. * **D. Obliteration of radial pulse:** This is the **least reliable and latest sign**. Compartment pressure rarely exceeds systolic arterial pressure; therefore, a palpable distal pulse does not rule out Volkmann’s ischemia. **NEET-PG High-Yield Pearls:** * **The 5 P’s:** Pain (earliest), Pallor, Paresthesia, Pulselessness (latest), and Paralysis. * **Most sensitive sign:** Pain on passive stretch. * **Gold Standard Diagnosis:** Measurement of intracompartmental pressure (using a Stryker monitor). A **Delta pressure** (Diastolic BP – Compartment Pressure) **< 30 mmHg** is diagnostic. * **Immediate Management:** Remove tight casts/bandages; if no improvement, urgent **Fasciotomy**.

Q: A 22-year-old man is brought to the emergency department following a rugby injury. Which of the following statements is false regarding the fracture shown?

Closed fracture. ***Closed fracture*** - This statement is **FALSE** - the fracture is actually an **open (compound) fracture** with visible bone fragments through the skin. - Open fractures require immediate **surgical debridement** and **antibiotic prophylaxis** to prevent infection and are classified using the **Gustilo-Anderson system**. *Comminuted fracture of the tibia* - This statement is **TRUE** - the fracture shows **multiple bone fragments** characteristic of a comminuted pattern. - Common in **high-energy trauma** like sports injuries, requiring complex surgical fixation with **intramedullary nailing** or **external fixation**. *Does not involve the articular surface* - This statement is **TRUE** - the fracture is located in the **mid-shaft (diaphysis)** of the tibia, sparing the joint surfaces. - **Diaphyseal fractures** have better healing potential compared to **intra-articular fractures** which can lead to post-traumatic arthritis. *Posteriorly displaced fracture* - This statement is **TRUE** - the **distal fragment** is displaced posteriorly relative to the proximal fragment. - Posterior displacement can compromise the **popliteal artery** and **posterior tibial nerve**, requiring vascular and neurological assessment.

Question 1

A 22-year-old male is admitted with a fracture of the left femur. Two days later, he becomes mildly confused, has a respiratory rate of 40/min, and a scattered petechial rash on his upper torso. Chest X-ray shows patchy alveolar opacities bilaterally. His arterial blood gas analysis is abnormal. What is the most likely diagnosis?

Accepted Answer

Fat embolism

Answer

Cerebral edema with early neurogenic pulmonary edema

Answer

Pulmonary thromboembolism

Answer

Chest contusion

Question 2

Growth disturbance, nonunion, elbow instability, and late ulnar nerve palsy are commonly seen in which type of fracture?

Accepted Answer

Fracture of the lateral condyle

Answer

Fracture of the supracondylar humerus

Answer

Fracture of the medial condyle

Answer

Fracture of the head of the radius

Question 3

What is the change in Gissane's angle in an intra-articular fracture of the calcaneum?

Accepted Answer

Increased

Answer

Reduced

Answer

Not changed

Answer

Variable

Question 4

What is the last step in fracture healing?

Accepted Answer

Remodeling

Answer

Hematoma

Answer

Callus formation

Answer

Consolidation

Question 5

Which nerve is most commonly involved in a fracture of the neck of the humerus?

Accepted Answer

Axillary nerve

Answer

Musculocutaneous nerve

Answer

Median nerve

Answer

Ulnar nerve

Question 6

A bucket handle tear occurs at the knee joint due to which of the following injuries?

Accepted Answer

Injury to the menisci

Answer

Injury to the medial collateral ligament

Answer

Injury to the lateral collateral ligament

Answer

Injury to the ligamentum patellae

Question 7

Which of the following are considered non-rigid fixation devices?

Accepted Answer

Both transosseous wire and Kirschner wire

Answer

Transosseous wire

Answer

Kirschner wire

Answer

None of the above

Question 8

What is the most important sign of Volkmann's ischemia?

Accepted Answer

Stretch pain

Answer

Pallor

Answer

Numbness

Answer

Obliteration of radial pulse

Question 9

A 22-year-old man is brought to the emergency department following a rugby injury. Which of the following statements is false regarding the fracture shown?

Accepted Answer

Closed fracture

Answer

Comminuted fracture of the tibia

Answer

Does not involve the articular surface

Answer

Posteriorly displaced fracture

Question 10

What is the maximum weight typically allowed in skeletal traction?

Accepted Answer

20 kg

Answer

5 kg

Answer

10 kg

Answer

30 kg

Trauma — MCQs

Trauma — MCQs

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