Trauma Practice Questions

Q: What is true about post-traumatic fat embolism syndrome?

Fracture mobility is a risk factor.. **Explanation:** Fat Embolism Syndrome (FES) is a systemic inflammatory response to fat globules released into the circulation, most commonly following fractures of long bones (like the femur) or the pelvis. **Why Option A is correct:** Fracture mobility is a significant risk factor. Movement at the fracture site increases intramedullary pressure and causes mechanical agitation, which forces fat droplets from the bone marrow into the torn venous sinusoids. This is why **early stabilization and internal fixation** of long bone fractures are the most effective ways to prevent FES. **Why other options are incorrect:** * **Option B:** Diabetes is not a recognized risk factor for FES. The primary risk factors are mechanical (multiple fractures, conservative management of long bone fractures) and physiological (hypovolemia/shock). * **Option C:** FES typically presents with **Tachycardia**, not bradycardia. The systemic inflammatory response and hypoxia (due to pulmonary involvement) trigger a sympathetic surge, leading to an increased heart rate. **NEET-PG High-Yield Pearls:** 1. **Gurd’s Criteria:** Used for diagnosis. Major criteria include **Axillary Petechiae** (pathognomonic but seen in only 20-50%), respiratory insufficiency/hypoxia, and CNS depression (confusion/coma). 2. **Classic Triad:** Dyspnea, Confusion, and Petechial rash (usually appearing 24–72 hours post-injury). 3. **Snowstorm Appearance:** Characteristic finding on Chest X-ray (diffuse bilateral pulmonary infiltrates). 4. **Treatment:** Primarily **supportive** (Oxygenation and maintenance of intravascular volume). Corticosteroids are controversial and not routinely recommended.

Q: Which nerve is most commonly damaged in posterior dislocation of the hip?

Sciatic nerve. **Explanation:** **1. Why Sciatic Nerve is Correct:** The **sciatic nerve** is the most commonly injured nerve in posterior hip dislocations (occurring in approximately 10–20% of cases). This is due to its anatomical proximity; the nerve exits the pelvis through the greater sciatic foramen and descends directly **posterior** to the acetabulum and the femoral head. When the femoral head is forced posteriorly out of the acetabulum (typically via a "dashboard injury"), it directly compresses or stretches the sciatic nerve. Specifically, the **peroneal division** of the sciatic nerve is more frequently affected than the tibial division. **2. Why Other Options are Incorrect:** * **Femoral Nerve:** Located **anterior** to the hip joint. It is more likely to be injured in *anterior* hip dislocations, which are much less common than posterior ones. * **Obturator Nerve:** Located **medially** and passes through the obturator canal. It is rarely injured in hip trauma but may be affected in medial wall acetabular fractures or anterior-inferior dislocations. * **Superior Gluteal Nerve:** Runs superior to the piriformis muscle. While it can be injured during surgical approaches (like the Hardinge approach), it is not typically damaged by the displacement of the femoral head in a posterior dislocation. **3. NEET-PG High-Yield Pearls:** * **Mechanism of Injury:** Most common is a "Dashboard Injury" (force applied to a flexed knee with the hip flexed and adducted). * **Clinical Presentation:** The limb is held in **Flexion, Adduction, and Internal Rotation** (F-AD-IR). * **Complications:** Avascular Necrosis (AVN) of the femoral head is the most serious late complication; Sciatic nerve palsy is the most common early neurological complication. * **Management:** Emergency closed reduction (e.g., Allis maneuver) should be performed within 6 hours to minimize AVN risk.

Q: Positive Trendelenburg's sign is seen in all EXCEPT?

Paralysis of gluteus Maximus. **Explanation:** The **Trendelenburg sign** is a clinical indicator of a dysfunctional **hip abductor mechanism**. For a stable pelvis during the single-leg stance phase of walking, three components must be intact: the **Power** (Gluteus medius and minimus), the **Fulcrum** (Head of the femur in the acetabulum), and the **Lever arm** (Neck of the femur). **Why Option A is the Correct Answer:** The Trendelenburg sign specifically tests the **Gluteus medius and minimus** (supplied by the Superior Gluteal Nerve). The **Gluteus maximus** (supplied by the Inferior Gluteal Nerve) is a primary extensor of the hip, not an abductor. Its paralysis leads to a "Gluteus Maximus Lurch" (extensor lurch) but does **not** result in a positive Trendelenburg sign. **Analysis of Other Options:** * **Option B (Paralysis of Gluteus medius/minimus):** This directly eliminates the "Power" source of the abductor mechanism, causing the pelvis to drop on the unsupported side. * **Option C (Fracture neck femur):** This disrupts the "Lever arm" and the structural integrity of the fulcrum, making it impossible for the abductors to stabilize the pelvis. * **Option D (Intertrochanteric fracture):** Similar to neck fractures, this causes a loss of the stable lever arm and painful inhibition of the abductor muscles, leading to a positive sign. **NEET-PG High-Yield Pearls:** * **The Sign:** When standing on the affected limb, the pelvis **drops** on the normal (unsupported) side. * **The Gait:** A compensated Trendelenburg sign results in a **Lurching gait** (the trunk shifts toward the affected side to maintain the center of gravity). * **Other Causes:** Congenital Dislocation of the Hip (CDH/DDH), Coxa Vara, and Slipped Capital Femoral Epiphysis (SCFE) all produce a positive Trendelenburg sign due to fulcrum or lever arm disruption.

Q: An elderly female presents with a history of a fall and inability to move. Following the fall, her leg was noted to be in an externally rotated position. There is tenderness in Scarpa's triangle, and limb movement is significantly limited due to pain. Initial X-ray ruled out hip fracture. What is the next diagnostic step?

MRI. **Explanation:** The clinical presentation of an elderly patient with a fall, external rotation of the limb, and tenderness in **Scarpa’s triangle** is highly suggestive of a **hip fracture** (specifically a femoral neck fracture). However, in elderly patients with osteoporosis, fractures can be **occult** (not visible on initial radiographs). 1. **Why MRI is Correct:** MRI is the **gold standard** for diagnosing occult hip fractures. It has nearly 100% sensitivity and can detect bone marrow edema and fracture lines within 24 hours of injury. When clinical suspicion is high but X-rays are negative, MRI is the immediate next step to prevent fracture displacement or avascular necrosis (AVN). 2. **Why other options are incorrect:** * **Repeat X-ray after one week:** While callus formation might eventually show a fracture, delaying diagnosis in an elderly patient leads to prolonged immobilization, increasing the risk of DVT, pneumonia, and pressure sores. * **Joint aspiration:** This is primarily used to diagnose septic arthritis or crystal arthropathy, not trauma-related fractures. * **Analgesics and manipulation:** Attempting manipulation without a diagnosis is dangerous and may displace an undisplaced fracture, compromising the blood supply (medial circumflex femoral artery). **Clinical Pearls for NEET-PG:** * **Occult Fracture:** A fracture that is clinically suspected but not visible on initial X-rays. * **Imaging Hierarchy:** If MRI is unavailable or contraindicated (e.g., pacemaker), a **CT scan** or **Bone Scan** (after 48-72 hours) are alternatives. * **Scarpa’s Triangle Tenderness:** A classic sign of intracapsular hip fractures. * **Positioning:** Femoral neck fractures typically present with **shortening and external rotation**.

Q: What is the characteristic position of the arm in an anterior shoulder dislocation?

By the side. In an anterior shoulder dislocation—the most common type of shoulder dislocation (95%)—the humeral head is displaced anteriorly and inferiorly out of the glenoid fossa. **Explanation of the Correct Answer:** The characteristic clinical presentation of a patient with an acute anterior shoulder dislocation is the arm held **by the side** (slightly abducted) and supported by the opposite hand. While the initial mechanism of injury often involves abduction and external rotation, once the dislocation is established, the patient typically presents with the arm fixed in **slight abduction and external rotation**, but functionally held close to the body (by the side) to minimize pain and muscle spasms. **Analysis of Incorrect Options:** * **In Abduction:** While the arm is slightly abducted (the "Hamilton Ruler Test" is positive because the arm cannot touch the side), it is not held in significant or overhead abduction. * **In Adduction:** This is incorrect because the displaced humeral head prevents the arm from being fully adducted to the side of the chest (Dugas Test). * **In External Rotation:** Although the arm is externally rotated, the most defining "positional" description in clinical exams is the arm being held by the side/slightly abducted. **NEET-PG High-Yield Clinical Pearls:** 1. **Flattening of the Shoulder:** Loss of the normal rounded contour of the deltoid (Square shoulder/Epaulette sign). 2. **Dugas Test:** The patient is unable to touch the opposite shoulder with the hand of the affected side. 3. **Hamilton Ruler Test:** A straight edge can touch both the acromion and the lateral epicondyle simultaneously. 4. **Associated Nerve Injury:** The **Axillary nerve** is the most commonly injured nerve (check for "regimental badge" anesthesia). 5. **Common Lesions:** Bankart lesion (labral tear) and Hill-Sachs lesion (compression fracture of the posterolateral humeral head).

Q: Which statement is not true regarding the Langenbeck-Kocher operation?

Superior exposure is very well achieved.. The **Kocher-Langenbeck (K-L) approach** is the standard posterior surgical approach to the acetabulum. Understanding its anatomical limitations is crucial for NEET-PG. ### **Explanation of the Correct Option** **Option C is the correct answer (the false statement)** because the K-L approach provides **limited superior exposure**. While it offers excellent access to the posterior column and posterior wall, it does not allow for adequate visualization of the superior aspect of the acetabulum (the "dome" or weight-bearing roof) or the iliac wing. To access the superior or anterior regions, an extended iliofemoral or a combined approach is often required. ### **Analysis of Other Options** * **Option A (True):** It is the "workhorse" approach for the **posterior segment**, providing direct access to the posterior column and posterior wall of the acetabulum. * **Option B (True):** The **anterior segment** (anterior wall and column) cannot be visualized through this posterior incision. Access is blocked by the femoral head and the pelvic anatomy. * **Option D (True):** **Sciatic nerve injury** is a well-documented complication of this approach, occurring in approximately **10%** of cases (range 2-10%). This is usually due to intraoperative traction on the nerve, particularly the peroneal division. ### **High-Yield Clinical Pearls for NEET-PG** * **Patient Positioning:** Usually performed in the prone or lateral position. * **Nerve Protection:** To minimize sciatic nerve tension during the procedure, the **knee must be kept flexed** (90°) and the **hip extended**. * **Structures at Risk:** Sciatic nerve, Superior Gluteal Artery (at the greater sciatic notch), and Inferior Gluteal Artery. * **Indications:** Posterior wall fractures, posterior column fractures, and certain transverse fractures of the acetabulum.

Question 1

What is true about post-traumatic fat embolism syndrome?

Accepted Answer

Fracture mobility is a risk factor.

Answer

Associated diabetes poses a risk.

Answer

Bradycardia occurs.

Answer

All of the above.

Question 2

A person is hit from behind by a scooter. The rider is thrown off and lands with their head hitting the kerb. They do not move, complain of severe pain in the neck, and are unable to turn their head. Well-meaning bystanders attempt to make them sit up. What is the best course of action in this situation?

Accepted Answer

Turn the individual onto their back, place a support behind their neck, and transport them to the nearest hospital.

Answer

Prop the individual up and give them water to drink.

Answer

Do not prop the individual up; turn them onto their face and rush them to the hospital.

Answer

Do not move the individual at all; carry them to the nearest hospital in the same position they have been in since their fall.

Question 3

What is the treatment of choice for a linear, non-displaced fracture of the body of the mandible in a patient with a full complement of teeth?

Accepted Answer

Interdental fixation

Answer

Kirschner wire

Answer

Circumferential wiring

Answer

External pin fixation

Question 4

What is the treatment for a severely comminuted fracture of the patella that cannot be reduced?

Accepted Answer

Patellectomy

Answer

Insertion of screws and wires

Answer

Physiotherapy alone

Answer

Removal of the smallest piece only

Question 5

Which nerve is most commonly damaged in posterior dislocation of the hip?

Accepted Answer

Sciatic nerve

Answer

Femoral nerve

Answer

Obturator nerve

Answer

Superior gluteal nerve

Question 6

Positive Trendelenburg's sign is seen in all EXCEPT?

Accepted Answer

Paralysis of gluteus Maximus

Answer

Paralysis of gluteus medius and minimus

Answer

Fracture neck femur

Answer

Intertrochanteric fracture

Question 7

Trendelenburg test would be positive in which of the following conditions?

Accepted Answer

L4-L5 disc herniation

Answer

L5-S1 disc herniation

Answer

Synovitis of the hip

Answer

Femoroacetabular impingement syndrome

Question 8

An elderly female presents with a history of a fall and inability to move. Following the fall, her leg was noted to be in an externally rotated position. There is tenderness in Scarpa's triangle, and limb movement is significantly limited due to pain. Initial X-ray ruled out hip fracture. What is the next diagnostic step?

Accepted Answer

MRI

Answer

Repeat X-ray after one week

Answer

Joint aspiration

Answer

Administer analgesics and attempt manipulation

Question 9

What is the characteristic position of the arm in an anterior shoulder dislocation?

Accepted Answer

By the side

Answer

In abduction

Answer

In adduction

Answer

In external rotation

Question 10

Which statement is not true regarding the Langenbeck-Kocher operation?

Accepted Answer

Superior exposure is very well achieved.

Answer

Provides adequate exposure of the posterior segment.

Answer

The anterior segment is not visualized adequately.

Answer

Sciatic nerve injury occurs in 10% of cases.

Trauma — MCQs

Trauma — MCQs

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