Trauma Practice Questions

Q: What is a straddle fracture?

Pelvis fracture. ### Explanation **Correct Answer: C. Pelvis fracture** A **Straddle Fracture** is a specific type of pelvic ring injury characterized by **bilateral fractures of the superior and inferior pubic rami**. It is typically caused by a direct blow to the midline of the bony pelvis (e.g., falling astride a beam or a motorcycle accident). From a biomechanical perspective, it is considered an **unstable** injury because it results in a "floating" anterior segment of the pelvis. The most significant clinical concern in straddle fractures is the high incidence of associated **genitourinary injuries** (up to 20%), particularly ruptures of the posterior urethra or bladder. --- ### Why other options are incorrect: * **A. Shoulder fracture:** Shoulder injuries are classified by specific eponyms like Bankart or Hill-Sachs lesions, but "straddle" refers specifically to the pelvic anatomy. * **B. Wrist fracture:** Common wrist fractures include Colles’, Smith’s, or Barton’s fractures, which involve the distal radius. * **D. Ankle fracture:** Ankle fractures are usually classified by the Lauge-Hansen or Danis-Weber systems based on the mechanism of rotation and fibular involvement. --- ### NEET-PG High-Yield Pearls: * **Mechanism:** Direct vertical impact to the perineum. * **Key Association:** Always rule out **urethral injury** (look for blood at the meatus, high-riding prostate, or inability to void). * **Radiology:** X-ray shows four fractures (bilateral superior and inferior rami). * **Malgaigne Fracture:** Another high-yield pelvic fracture involving vertical shear (fracture through the pubic rami and ipsilateral SI joint/sacrum). * **Open Book Fracture:** Results from Antero-posterior compression (APC), leading to symphysis pubis diastasis.

Q: Complications of supracondylar fracture of humerus include all of the following except:

Nonunion. **Explanation:** Supracondylar fracture of the humerus is the most common pediatric elbow fracture. The correct answer is **Nonunion** because this fracture occurs through the metaphyseal region of the distal humerus. Metaphyseal bone is highly vascular and has a robust healing potential; consequently, nonunion is extremely rare in supracondylar fractures. **Analysis of Options:** * **Nonunion (Correct):** As mentioned, the excellent blood supply to the metaphysis ensures rapid healing. If a distal humerus fracture fails to unite, it is more likely a fracture of the **lateral condyle** (which is intra-articular and bathed in synovial fluid). * **Elbow Stiffness:** This is the **most common** complication. It results from prolonged immobilization or soft tissue fibrosis following the trauma. * **Malunion:** Very common, typically resulting in a **Cubitus Varus** (Gunstock deformity) due to inadequate reduction of the medial tilt or rotation. It is primarily a cosmetic deformity rather than a functional one. * **Myositis Ossificans:** This occurs due to heterotopic ossification in the brachialis muscle, often triggered by forceful passive stretching or vigorous massage post-injury. **Clinical Pearls for NEET-PG:** 1. **Most common complication:** Elbow stiffness. 2. **Most common deformity:** Cubitus Varus (Malunion). 3. **Most serious immediate complication:** Volkmann’s Ischemic Contracture (VIC) due to brachial artery injury or Compartment Syndrome. 4. **Most common nerve injured:** Anterior Interosseous Nerve (AIN) in extension type; Ulnar nerve in flexion type.

Q: Mallet finger is due to avulsion of the extensor tendon of which structure?

Distal phalanx. **Explanation:** **Mallet Finger** (also known as baseball finger) is a common hand injury caused by the disruption of the **extensor digitorum tendon** at its insertion point. 1. **Why the Distal Phalanx is correct:** The extensor tendon inserts into the dorsal aspect of the **base of the distal phalanx**. When a sudden forceful flexion occurs at the Distal Interphalangeal (DIP) joint while the finger is extended (e.g., being struck by a ball), the tendon is either ruptured or avulses a small bone fragment from the distal phalanx. This results in an inability to actively extend the DIP joint, leading to a characteristic "droop" of the fingertip. 2. **Why other options are incorrect:** * **Proximal Phalanx:** This is the site of insertion for the primary extensors of the MCP joint; injury here does not cause a mallet deformity. * **Middle Phalanx:** The **central slip** of the extensor expansion inserts here. Rupture of the central slip leads to a **Boutonnière deformity**, not Mallet finger. * **Metacarpals:** These are located in the palm/hand; extensor injuries here affect the MCP joint or wrist extension. **Clinical Pearls for NEET-PG:** * **Clinical Feature:** The patient presents with a flexed DIP joint and an inability to actively straighten the fingertip. * **Management:** Most cases are treated conservatively with a **Mallet splint** (holding the DIP joint in continuous slight hyperextension) for 6–8 weeks. * **Radiology:** An X-ray is essential to rule out a "Bony Mallet" (avulsion fracture). * **Complication:** If left untreated, it may progress to a **Swan-neck deformity** due to dorsal displacement of the lateral bands.

Q: What is the most common complication of a scaphoid fracture?

Avascular necrosis. **Explanation:** The scaphoid is the most commonly fractured carpal bone. The correct answer is **Avascular Necrosis (AVN)** due to the bone's unique **retrograde blood supply**. **1. Why Avascular Necrosis is correct:** The blood supply to the scaphoid enters primarily through the distal pole via the radial artery branches and flows proximally. When a fracture occurs—especially at the **proximal pole** or the **waist**—this retrograde flow is interrupted. The proximal fragment is left without a blood supply, leading to AVN in approximately 15-30% of cases. This is a classic "high-yield" anatomical concept in orthopaedics. **2. Why other options are incorrect:** * **Malunion:** While it can occur (leading to a "humpback" deformity), it is less frequent than AVN or non-union. * **Wrist Stiffness:** This is a common *sequela* of prolonged casting or surgery, but it is considered a functional outcome rather than the primary pathological complication of the fracture itself. * **Arthritis:** Specifically, **SNAC (Scaphoid Non-union Advanced Collapse)** is a long-term complication, but it usually occurs secondary to untreated non-union or AVN. **Clinical Pearls for NEET-PG:** * **Most common site:** Scaphoid waist (60-70%). * **Highest risk of AVN:** Proximal pole fractures (nearly 100% risk due to total ischemia). * **Clinical Sign:** Tenderness in the **Anatomical Snuffbox**. * **Radiology:** If initial X-rays are negative but clinical suspicion is high, repeat X-rays in 10-14 days or perform an **MRI** (the most sensitive investigation). * **Management:** Undisplaced fractures are treated with a **Scaphoid cast** (Glass-holding position); displaced fractures require internal fixation with a **Herbert screw**.

Q: In the management of long bone fractures, which of the following procedures can be performed?

All of the above. **Explanation:** The management of long bone fractures (such as the femur, tibia, and humerus) is guided by the fracture personality, the patient’s physiological status, and the condition of the surrounding soft tissues. There is no "one-size-fits-all" approach; rather, surgeons choose from several fixation methods based on specific indications. * **Intramedullary (IM) Nailing:** This is the **gold standard** for most diaphyseal (shaft) fractures of long bones (especially the femur and tibia). It provides internal splintage and allows for early weight-bearing by sharing the load with the bone. * **Plating (Open Reduction and Internal Fixation - ORIF):** This is preferred for fractures involving the **metaphysis or epiphysis** (articular surfaces) where anatomical reduction is crucial. It is also used in the forearm (radius/ulna) to maintain rotational stability. * **External Fixation:** This is the treatment of choice for **Grade III open fractures** with severe soft tissue injury, polytrauma patients (Damage Control Orthopaedics), or when there is active infection. It provides stability without placing bulky hardware in a contaminated or compromised wound. Since all three methods are standard surgical interventions depending on the clinical scenario, **Option D** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard for Femur Shaft:** Antegrade Intramedullary Nailing. * **Forearm Fractures:** Plating is superior to nailing because it preserves the interosseous space and rotational function. * **Damage Control:** External fixation is used to "stabilize and move on" in hemodynamically unstable patients. * **Primary Bone Healing:** Occurs with absolute stability (Plating); **Secondary Bone Healing** (with callus) occurs with relative stability (Nailing/Ex-Fix).

Q: Malunited supracondylar humerus fracture causes which deformity?

Cubitus varus. **Explanation:** Supracondylar fractures of the humerus are the most common pediatric elbow fractures. The most frequent late complication of a malunited supracondylar fracture (specifically the extension type) is **Cubitus Varus**, also known as **"Gunstock Deformity."** **Why Cubitus Varus is correct:** The deformity occurs due to the malalignment of the distal fragment, primarily caused by **coronal plane tilt (medial tilt)**, often combined with internal rotation and posterior displacement. While it is primarily a cosmetic issue and rarely affects the range of motion or joint function, it is a classic hallmark of poor reduction in these fractures. **Analysis of Incorrect Options:** * **Dinner Fork Deformity:** This is characteristic of a **Colles’ fracture** (distal radius fracture with dorsal displacement), not elbow trauma. * **Cubitus Valgus:** While less common in supracondylar fractures, cubitus valgus is the classic complication of a **Non-union of the Lateral Condyle** of the humerus. Chronic cubitus valgus can lead to tardy ulnar nerve palsy. **High-Yield Clinical Pearls for NEET-PG:** * **Most common complication:** Stiffness (overall); Cubitus varus (most common deformity). * **Most serious complication:** Volkmann’s Ischemic Contracture (VIC) due to injury to the brachial artery or compartment syndrome. * **Nerve Injuries:** The **Anterior Interosseous Nerve (AIN)** is the most commonly injured nerve in extension-type fractures, while the **Ulnar nerve** is most commonly injured in flexion-type fractures or during percutaneous pinning (iatrogenic). * **Treatment of Cubitus Varus:** If cosmetically unacceptable, it is corrected using a **French Osteotomy** (Lateral closed-wedge osteotomy).

Q: Maximum shortening of limbs occurs in which condition?

Post-dislocation of the hip. **Explanation:** The degree of limb shortening in hip injuries depends on the extent of proximal migration of the femoral head or shaft relative to the acetabulum. **1. Why Posterior Dislocation of the Hip is Correct:** In a posterior dislocation, the femoral head is forced out of the acetabulum and driven superiorly and posteriorly onto the ilium. Because the head is completely displaced from its socket and rests significantly higher on the pelvic bone, it results in the **maximum clinical shortening** (typically 2–4 cm). This is classically associated with a "Dashboard injury" and presents with a limb that is **shortened, adducted, and internally rotated.** **2. Analysis of Incorrect Options:** * **Trochanteric Femur Fracture:** While shortening occurs due to the pull of the gluteal and hip flexor muscles, it is generally less than in a posterior dislocation because the capsule and some bony contact often limit the proximal migration. * **Femoral Neck Fracture:** Shortening is a feature (due to muscle spasm), but it is usually **minimal to moderate** (about 1–2 cm). The limb is typically abducted and externally rotated. * **Anterior Dislocation of the Hip:** This condition usually presents with a limb that appears **lengthened** (or of normal length) because the femoral head is displaced inferiorly and anteriorly (obturator type). The limb is classically abducted and externally rotated. **3. Clinical Pearls for NEET-PG:** * **Posterior Dislocation:** Shortened + Adducted + Internally Rotated (Mnemonic: **S**hort **A**nd **I**n). * **Neck of Femur Fracture:** Shortened + Abducted + Externally Rotated (Mnemonic: **S**hort **A**nd **E**x). * **Nerve Injury:** Posterior dislocation is most commonly associated with **Sciatic nerve** palsy (specifically the peroneal component). * **Emergency:** Hip dislocations are orthopedic emergencies due to the high risk of **Avascular Necrosis (AVN)** of the femoral head.

Question 1

What is a straddle fracture?

Accepted Answer

Pelvis fracture

Answer

Shoulder fracture

Answer

Wrist fracture

Answer

Ankle fracture

Question 2

Complications of supracondylar fracture of humerus include all of the following except:

Accepted Answer

Nonunion

Answer

Elbow stiffness

Answer

Malunion

Answer

Myositis ossificans

Question 3

Mallet finger is due to avulsion of the extensor tendon of which structure?

Accepted Answer

Distal phalanx

Answer

Proximal phalanx

Answer

Middle phalanx

Answer

Metacarpals

Question 4

Which of the following is a true statement regarding posterior dislocation of the shoulder joint?

Accepted Answer

Internal rotation

Answer

External rotation

Answer

Axillary nerve palsy

Answer

Anterior hollowness

Question 5

What is the consequence of weakness of the Vastus Medialis?

Accepted Answer

Lateral dislocation of the patella

Answer

Patellar Clunk Syndrome

Answer

Medial dislocation of the patella

Answer

Weakness in abduction at the hip joint

Question 6

Burst fracture of the cervical spine is typically caused by which mechanism of injury?

Accepted Answer

Vertical compression injury

Answer

Hyperextension and hyperflexion forces (whiplash)

Answer

Axial loading (fall of weight on the head)

Answer

High-energy impact from a car accident

Question 7

What is the most common complication of a scaphoid fracture?

Accepted Answer

Avascular necrosis

Answer

Malunion

Answer

Wrist stiffness

Answer

Arthritis

Question 8

In the management of long bone fractures, which of the following procedures can be performed?

Accepted Answer

All of the above

Answer

Intramedullary nailing

Answer

Plating

Answer

External fixation

Question 9

Malunited supracondylar humerus fracture causes which deformity?

Accepted Answer

Cubitus varus

Answer

Dinner fork deformity

Answer

Cubitus valgus

Answer

None

Question 10

Maximum shortening of limbs occurs in which condition?

Accepted Answer

Post-dislocation of the hip

Answer

Trochanteric femur fracture

Answer

Femoral neck fracture

Answer

Anterior dislocation of the hip

Trauma — MCQs

Trauma — MCQs

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