Trauma Practice Questions

Q: Which nerve is least likely to be affected by entrapment syndrome?

Femoral. **Explanation:** The correct answer is **Femoral nerve (Option A)**. Nerve entrapment syndromes occur when a peripheral nerve is compressed as it passes through a narrow anatomical space (fibro-osseous tunnels or muscular openings). The **Femoral nerve** is least likely to be affected by entrapment because of its anatomical course. It emerges from the psoas major muscle and enters the thigh deep to the inguinal ligament, where it is relatively well-protected and lies in a wide space. Unlike the other nerves listed, it does not pass through a tight, restrictive osteofibrous canal that is prone to chronic compression. **Why the other options are incorrect:** * **Median Nerve (Option D):** This is the most common nerve involved in entrapment (Carpal Tunnel Syndrome) as it passes through the narrow carpal tunnel at the wrist. * **Ulnar Nerve (Option C):** Frequently entrapped at the elbow (Cubital Tunnel Syndrome) or the wrist (Guyon’s canal). * **Radial Nerve (Option B):** Can be entrapped in the radial tunnel (Radial Tunnel Syndrome) or compressed at the spiral groove (Saturday Night Palsy). **High-Yield NEET-PG Pearls:** * **Most common entrapment neuropathy:** Carpal Tunnel Syndrome (Median nerve). * **Meralgia Paraesthetica:** Entrapment of the *Lateral Femoral Cutaneous Nerve* (not the femoral nerve itself) under the inguinal ligament. * **Tarsal Tunnel Syndrome:** Entrapment of the Posterior Tibial nerve at the ankle. * **Guyon’s Canal:** Site of Ulnar nerve compression at the wrist, often seen in long-distance cyclists.

Q: In a fracture of the femur, which fragment commonly damages the popliteal artery?

Distal fragment. In a **supracondylar fracture of the femur**, the anatomical relationship between the bone and the neurovascular bundle is critical for clinical practice. ### **Why the Distal Fragment is Correct** The popliteal artery is fixed in the popliteal fossa, lying in close proximity to the posterior surface of the femur. When a supracondylar fracture occurs, the **distal fragment** is characteristically tilted **posteriorly**. This displacement is caused by the powerful traction of the **gastrocnemius muscle**, which originates from the femoral condyles. This posterior tilting forces the sharp proximal edge of the distal fragment directly into the popliteal artery, leading to arterial occlusion, transection, or intimal injury. ### **Explanation of Incorrect Options** * **Proximal Fragment:** The proximal fragment is usually displaced anteriorly and laterally due to the pull of the quadriceps and adductors. It is further away from the popliteal vessels. * **Muscle Hematoma & Tissue Swelling:** While these can cause Compartment Syndrome (secondary compression), they do not cause the direct mechanical "piercing" or "kinking" injury to the artery associated with this specific fracture pattern. ### **NEET-PG High-Yield Pearls** * **The "Golden Rule":** Always check the distal pulses (Dorsalis Pedis and Posterior Tibial) in any distal femur or knee injury. * **Associated Nerve Injury:** The peroneal nerve is also at risk, though vascular injury is the most limb-threatening complication. * **Management:** This is a surgical emergency. If pulses are absent, an urgent **Angiography** or surgical exploration is required. * **Fixation:** These fractures are typically managed with a Distal Femoral Nail (DFN) or a Locking Compression Plate (LCP).

Q: Which of the following features is essential in the diagnosis of a fracture of a bone?

Partial or complete loss of continuity of the bone. ### Explanation **Correct Answer: C. Partial or complete loss of continuity of the bone** **Why it is correct:** By definition, a fracture is a **break in the structural continuity of a bone**. This may range from a simple crack (stress fracture or greenstick fracture) to a complex comminution. While clinical signs like pain and swelling suggest an injury, the **essential diagnostic criterion**—both pathologically and radiologically—is the disruption of the bone's cortex or internal architecture. **Analysis of Incorrect Options:** * **A. Deformity:** While common in displaced fractures, many fractures (such as impacted, hairline, or undisplaced fractures) present with no visible deformity. Conversely, joint dislocations can cause significant deformity without an actual bone fracture. * **B. Crepitus:** This is the grating sensation/sound produced by the friction of fractured bone ends. Although it is a **pathognomonic** sign of a fracture, it is not "essential" for diagnosis. In fact, seeking crepitus is discouraged clinically as it causes significant pain and can worsen soft tissue injury or neurovascular damage. It is also absent in impacted or incomplete fractures. **High-Yield Clinical Pearls for NEET-PG:** * **Pathognomonic signs of fracture:** Abnormal mobility and crepitus (but these are not essential for diagnosis). * **Standard Imaging:** Always obtain at least two views (**Anteroposterior and Lateral**) and include the **joint above and the joint below** the injury site (Rule of Two). * **Tenderness:** Localized "point tenderness" over a bone is the most sensitive clinical sign for a fracture in a conscious patient. * **Greenstick Fracture:** A common pediatric fracture where the continuity is only partially lost (one side of the cortex remains intact).

Q: Fracture of the shaft of the humerus is most commonly associated with injury to which of the following nerves?

Radial nerve. **Explanation:** The **Radial nerve** is the most commonly injured nerve in fractures of the humeral shaft, particularly those involving the **middle and distal thirds**. This is due to the intimate anatomical relationship where the nerve winds around the posterior aspect of the humerus in the **spiral groove** (radial groove). In this location, the nerve is in direct contact with the periosteum, making it highly susceptible to injury from displaced fracture fragments or entrapment in the callus. **Analysis of Options:** * **Radial Nerve (Correct):** Its proximity to the spiral groove makes it the primary nerve at risk. Injury typically results in **wrist drop** and loss of sensation over the first dorsal web space. * **Ulnar Nerve:** Usually injured in fractures of the **medial epicondyle** or supracondylar fractures (Tardy Ulnar Palsy). * **Median Nerve:** More commonly associated with **supracondylar fractures** of the humerus (along with the brachial artery) rather than shaft fractures. * **Musculocutaneous Nerve:** Rarely injured in humeral fractures as it is well-protected by the biceps and brachialis muscles. **Clinical Pearls for NEET-PG:** 1. **Holstein-Lewis Fracture:** A spiral fracture of the **distal 1/3rd** of the humeral shaft specifically associated with radial nerve neuropraxia. 2. **Management:** Most radial nerve palsies associated with closed humeral shaft fractures are **neuropraxias** and resolve spontaneously (85-90% recovery rate). Immediate exploration is generally not indicated unless it is an open fracture or a nerve palsy develops *after* manipulation. 3. **Splinting:** The **Sarmiento brace** (functional bracing) is the gold standard for definitive non-operative management of humeral shaft fractures.

Q: A patient sustained a left knee injury in a road traffic accident, and the Dial test was positive. What is the most likely cause?

Posterolateral Corner Injury. **Explanation:** The **Dial Test** (also known as the Tibial External Rotation Test) is the clinical gold standard for diagnosing injuries to the **Posterolateral Corner (PLC)** of the knee. **1. Why Option B is Correct:** The PLC consists of the popliteus tendon, fibular (lateral) collateral ligament, and popliteofibular ligament. These structures primarily resist **external rotation** of the tibia. During the Dial Test, the patient is prone, and the clinician externally rotates the feet. * An increase in external rotation of **>10°** compared to the normal side at **30° of knee flexion** indicates an isolated **PLC injury**. * If the instability persists or increases at **90° of flexion**, it suggests a combined injury of the PLC and the **Posterior Cruciate Ligament (PCL)**. **2. Why Other Options are Incorrect:** * **Option A (MCL):** Evaluated using the Valgus Stress Test. MCL injuries cause medial joint line opening, not isolated rotational instability. * **Options C & D (Meniscal Tears):** Diagnosed via McMurray’s test, Apley’s Grind test, or Thessaly test. While meniscal tears cause clicking or locking, they do not result in the specific rotational laxity seen in a positive Dial test. **Clinical Pearls for NEET-PG:** * **Components of PLC:** Popliteus muscle/tendon, LCL, and Popliteofibular ligament (The "Unholy Trio" of the lateral side). * **Common Nerve Injury:** PLC injuries are frequently associated with **Peroneal Nerve (Common Fibular Nerve)** palsy, leading to foot drop. * **Gait Sign:** Patients with chronic PLC deficiency often exhibit a **varus thrust gait**.

Q: Bankart lesion occurs in patients with which of the following?

Anterior shoulder dislocation. **Explanation:** A **Bankart lesion** is the most common pathological finding in recurrent **anterior shoulder dislocation**. It involves an avulsion of the **anteroinferior glenoid labrum** from the underlying glenoid bone. This occurs when the humeral head is forced anteriorly and inferiorly, tearing the labrum and the attached inferior glenohumeral ligament (IGHL) complex. If a fragment of the glenoid bone is also fractured, it is termed a "Bony Bankart." **Analysis of Options:** * **Anterior shoulder dislocation (Correct):** This is the most common type of shoulder dislocation (95%). The mechanism involves forced abduction and external rotation, leading to the Bankart lesion and the associated **Hill-Sachs lesion** (compression fracture of the posterolateral humeral head). * **Posterior shoulder dislocation:** This is associated with a **Reverse Bankart lesion** (detachment of the posterior labrum) and a **Reverse Hill-Sachs lesion** (McLaughlin lesion), typically seen after seizures or electric shocks. * **Posterior elbow dislocation:** This typically involves injury to the medial collateral ligament and potential fractures of the coronoid process or radial head (Terrible Triad), but not a Bankart lesion. * **Posterior hip dislocation:** This is associated with acetabular posterior wall fractures and sciatic nerve injuries. **NEET-PG High-Yield Pearls:** * **Gold Standard Investigation:** MRI Arthrography is the best modality to visualize a Bankart lesion. * **Associated Lesion:** Hill-Sachs lesion (found in ~80% of cases). * **Treatment:** Recurrent cases often require surgical repair (Bankart repair), which can be done arthroscopically or via open surgery (e.g., Putti-Platt or Bristow-Latarjet procedure if there is significant bone loss).

Q: Traumatic myositis ossificans is also known as:

All of the above. **Explanation:** **Traumatic Myositis Ossificans (MO)** refers to the formation of heterotopic lamellar bone within soft tissues (usually muscles) following trauma. It is a non-neoplastic condition where a hematoma undergoes organization and subsequent ossification rather than resorption. The correct answer is **D (All of the above)** because the condition is often named based on the specific occupational or repetitive trauma that triggers it: 1. **Drill Bone:** Occurs in the **deltoid** or pectoral muscles of infantry soldiers due to the repetitive recoil of a rifle during drill practice. 2. **Rider’s Bone:** Occurs in the **adductor muscles** of the thigh (specifically Adductor Longus) in horseback riders due to chronic friction and strain against the saddle. 3. **Exercise Bone:** A general term used when ossification occurs in muscles subjected to heavy, repetitive athletic strain or acute injury during vigorous exercise. **Clinical Pearls for NEET-PG:** * **Common Site:** The most common site for traumatic MO is the **Brachialis** muscle (following supracondylar fracture or elbow dislocation) and the **Quadriceps**. * **Pathophysiology:** It follows the "Zoning Phenomenon"—the lesion is more mature (calcified) at the periphery and immature (cellular) in the center. This distinguishes it from Osteosarcoma, which is more mature at the center. * **Management:** The most important rule is **never to massage** a recent injury or perform forceful passive stretching, as this increases the risk of MO. * **Treatment:** Initial management is rest and NSAIDs (Indomethacin). Surgery is only indicated after the bone has "matured" (usually 6–12 months), evidenced by a well-defined cortex on X-ray and a cold bone scan.

Q: All of the following are true about intertrochanteric fracture of the femur except:

Intracapsular.. ### Explanation **Intertrochanteric (IT) fractures** are extracapsular fractures occurring between the greater and lesser trochanters. **1. Why Option D is the Correct Answer (The "Except"):** The hip joint capsule attaches anteriorly to the intertrochanteric line and posteriorly to the femoral neck (medial to the intertrochanteric crest). Therefore, IT fractures occur **outside the joint capsule (extracapsular)**. This is a critical distinction because, unlike intracapsular neck of femur fractures, IT fractures have a rich blood supply and do not typically lead to avascular necrosis (AVN). **2. Analysis of Other Options:** * **Option A (Commoner than neck of femur):** IT fractures are generally more common than neck of femur fractures, especially in the elderly population with osteoporosis. * **Option B (Treatment):** The gold standard for stable IT fractures is the **Dynamic Hip Screw (DHS)**. For unstable or reverse oblique patterns, the **Proximal Femoral Nail (PFN)** is preferred as it is an intramedullary device providing better biomechanical stability. * **Option C (Malunion):** Because the trochanteric region is composed of cancellous bone with an excellent blood supply, these fractures almost always heal (non-union is rare). However, they frequently heal in a deformed position, most commonly **coxa vara** and shortening, leading to malunion. **Clinical Pearls for NEET-PG:** * **Clinical Presentation:** The affected limb shows marked **shortening and external rotation** (often up to 90 degrees, touching the bed), which is more pronounced than in neck of femur fractures. * **Blood Loss:** Being extracapsular and involving cancellous bone, IT fractures are associated with significant concealed blood loss (up to 1–1.5 liters). * **Evans Classification:** Used to grade the stability of IT fractures. * **Complication:** The most common complication is **malunion**; the rarest is AVN.

Question 1

Which of the following is NOT typically done in a patient presenting with Volkmann's ischemia?

Accepted Answer

Sympathetic ganglion blockade

Answer

Split open the plaster of Paris cast and bandage

Answer

Decompression by fasciotomy

Answer

Exploration

Question 2

Which nerve is least likely to be affected by entrapment syndrome?

Accepted Answer

Femoral

Answer

Radial

Answer

Ulnar

Answer

Median

Question 3

In a fracture of the femur, which fragment commonly damages the popliteal artery?

Accepted Answer

Distal fragment

Answer

Proximal fragment

Answer

Muscle hematoma

Answer

Tissue swelling

Question 4

Which of the following features is essential in the diagnosis of a fracture of a bone?

Accepted Answer

Partial or complete loss of continuity of the bone

Answer

Deformity

Answer

Crepitus

Answer

None of the above

Question 5

Fracture of the shaft of the humerus is most commonly associated with injury to which of the following nerves?

Accepted Answer

Radial nerve

Answer

Ulnar nerve

Answer

Median nerve

Answer

Musculocutaneous nerve

Question 6

A patient sustained a left knee injury in a road traffic accident, and the Dial test was positive. What is the most likely cause?

Accepted Answer

Posterolateral Corner Injury

Answer

Medial Collateral Ligament Injury

Answer

Lateral Meniscus Tear

Answer

Medial Meniscal Injury

Question 7

Which of the following statements about post-traumatic fat embolism syndrome are true?

Accepted Answer

Fracture mobility, thrombocytopenia, and PaO2 on ABG are true; associated diabetes and bradycardia are false.

Answer

Fracture mobility, associated diabetes, and bradycardia are true; thrombocytopenia and PaO2 on ABG are false.

Answer

All statements are false.

Answer

All statements are true.

Question 8

Bankart lesion occurs in patients with which of the following?

Accepted Answer

Anterior shoulder dislocation

Answer

Posterior shoulder dislocation

Answer

Posterior elbow dislocation

Answer

Posterior hip dislocation

Question 9

Traumatic myositis ossificans is also known as:

Accepted Answer

All of the above

Answer

Drill bone

Answer

Rider's bone

Answer

Exercise bone

Question 10

All of the following are true about intertrochanteric fracture of the femur except:

Accepted Answer

Intracapsular.

Answer

Commoner than fracture of the neck of the femur.

Answer

Treatment is proximal femoral nail or dynamic hip screw.

Answer

Associated with malunion.

Trauma — MCQs

Trauma — MCQs

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