Trauma Practice Questions

Q: Axillary nerve injury is most likely to be seen in which of the following conditions?

Shoulder dislocation. **Explanation:** The **Axillary nerve (C5, C6)** is the most commonly injured nerve in **Anterior Shoulder Dislocation**. This occurs because the nerve winds around the surgical neck of the humerus in the quadrangular space, placing it in close proximity to the inferior aspect of the glenohumeral joint capsule. When the humeral head displaces antero-inferiorly, it can stretch or compress the nerve (neuropraxia). **Analysis of Options:** * **A. Shoulder Dislocation (Correct):** Specifically, anterior dislocation is the most common cause. Clinical signs include loss of the rounded contour of the shoulder (deltoid atrophy) and sensory loss over the "Regimental Badge" area. * **B. Coracoid Process Fracture:** This is a rare injury usually associated with acromioclavicular joint disruptions. While the musculocutaneous nerve is nearby, axillary nerve involvement is not typical. * **C. Humerus Shaft Fracture:** This is classically associated with **Radial nerve injury** (especially in Holstein-Lewis fractures of the distal third), as the nerve lies in the spiral groove. * **D. Brachial Plexus Injury:** While the axillary nerve is a branch of the posterior cord of the brachial plexus, a global plexus injury involves multiple nerves (e.g., Erb’s or Klumpke’s palsy). Shoulder dislocation is a more specific and frequent cause of isolated axillary nerve palsy. **NEET-PG High-Yield Pearls:** * **Test for Axillary Nerve:** Check for sensation over the lateral aspect of the upper arm (Regimental Badge area) and isometric contraction of the **Deltoid**. * **Surgical Neck Fracture:** This is the second most common cause of axillary nerve injury. * **Most common type of shoulder dislocation:** Anterior (95%). * **Associated Injury:** Always rule out a **Bankart lesion** or **Hill-Sachs lesion** in recurrent dislocations.

Q: If an adolescent boy falls on an outstretched hand, which is the most common bone to be injured?

Scaphoid fracture. **Explanation:** The mechanism of injury—falling on an outstretched hand (FOOSH)—is a classic presentation in orthopaedics, but the specific injury pattern varies significantly with the patient's age. **Why Scaphoid Fracture is correct:** In **adolescents and young adults**, the scaphoid is the most commonly fractured carpal bone. During this developmental stage, the physis (growth plate) of the distal radius is often stronger than the scaphoid bone itself. When force is transmitted through the radial side of the wrist in extension, the scaphoid bears the brunt of the impact, leading to a fracture. **Analysis of Incorrect Options:** * **A. Fracture of the lower end of the radius (Colles’):** This is the most common FOOSH injury in **elderly patients** (especially post-menopausal women) due to osteoporotic changes. * **B. Fracture of both bones of the forearm:** While common in children, it is less frequent than specific physeal or carpal injuries in the adolescent age group. * **C. Supracondylar fracture of the humerus:** This is the most common FOOSH injury in **children (ages 5–10)** because the supracondylar area is the thinnest part of the distal humerus during early childhood. **High-Yield Clinical Pearls for NEET-PG:** * **Age-wise FOOSH injuries:** * Child: Supracondylar fracture. * Adolescent/Young Adult: Scaphoid fracture. * Elderly: Colles’ fracture. * **Clinical Sign:** Tenderness in the **Anatomical Snuffbox** is the hallmark of a scaphoid fracture. * **Complication:** The scaphoid has a **retrograde blood supply** (distal to proximal), making the proximal pole highly susceptible to **Avascular Necrosis (AVN)** and non-union. * **Radiology:** Initial X-rays may be negative; if clinical suspicion persists, repeat X-ray in 10–14 days or perform an MRI.

Q: Which traumatic fracture is most likely to show avascular necrosis?

Femoral neck. **Explanation:** The risk of **Avascular Necrosis (AVN)** is highest in bones with a "precarious" blood supply—specifically those where the blood vessels enter at one end and travel retrograde, or where the bone is largely covered by articular cartilage with limited periosteal entry points. **1. Why Femoral Neck is the Correct Answer:** The femoral neck is an **intracapsular** structure. Its primary blood supply comes from the **medial circumflex femoral artery** via retinacular vessels. A fracture in this region often tears these vessels, leaving the femoral head completely ischemic. Unlike extracapsular fractures (like intertrochanteric), there is no surrounding muscle or robust periosteum to provide collateral circulation, making AVN a very common complication (up to 30-40%). **2. Analysis of Incorrect Options:** * **Surgical neck of humerus:** This is an extracapsular area with a rich blood supply from the anterior and posterior circumflex humeral arteries and surrounding rotator cuff musculature. AVN is rare here compared to the anatomical neck. * **Body of talus:** While the talus is a high-risk site for AVN (Hawkins sign), the question asks which is *most likely*. Statistically, femoral neck fractures are far more common in clinical practice and exams as the classic example of post-traumatic AVN. * **Cuboid:** This is a tarsal bone with excellent ligamentous and vascular attachments; AVN is extremely rare. **Clinical Pearls for NEET-PG:** * **Common sites for AVN:** Femoral head (most common), Scaphoid (proximal pole), Talus (body), and Lunate (Kienbock’s disease). * **Investigation of Choice:** **MRI** is the most sensitive investigation for early detection of AVN (shows changes before X-ray). * **Garden Classification:** Used for femoral neck fractures; Stages III and IV have the highest risk of AVN due to complete displacement.

Q: Pipkin fracture is defined as:

Head of femur fracture. ### Explanation **Correct Answer: B. Head of femur fracture** **Medical Concept:** A **Pipkin fracture** refers specifically to a fracture of the **femoral head** associated with a posterior dislocation of the hip. It is a high-energy injury, typically resulting from a "dashboard injury" where a direct force is transmitted through the femur while the hip is flexed. The Pipkin classification is used to grade these injuries based on the location of the fracture relative to the fovea capitis and the presence of associated femoral neck or acetabular fractures. **Analysis of Incorrect Options:** * **A. Head of radius fracture:** These are common elbow injuries often classified by the **Mason Classification**, not Pipkin. * **C. Fracture dislocation of ankle:** Common eponyms for ankle fractures include **Pott’s fracture**, **Cotton’s fracture** (trimalleolar), or **Lauge-Hansen/Danis-Weber** classifications. * **D. Fracture neck of femur:** These are intracapsular fractures classified by **Garden’s** (based on displacement) or **Pauwels'** (based on verticality of the fracture line) classifications. **High-Yield Clinical Pearls for NEET-PG:** * **Pipkin Classification:** * **Type I:** Fracture inferior to the fovea capitis (small fragment). * **Type II:** Fracture superior to the fovea capitis (large fragment). * **Type III:** Type I or II associated with a femoral neck fracture (high risk of AVN). * **Type IV:** Type I or II associated with an acetabular rim fracture. * **Complications:** The most dreaded complication of Pipkin fractures is **Avascular Necrosis (AVN)** of the femoral head due to disrupted blood supply, followed by post-traumatic arthritis. * **Emergency:** Hip dislocation is an orthopedic emergency; reduction must be performed within 6 hours to minimize AVN risk.

Q: Which treatment plan would lead to rigid fixation of the fracture site?

Eccentric compression plate osteosynthesis. ### Explanation **Concept of Rigid vs. Biological Fixation** In orthopaedics, **rigid (absolute) stability** is achieved when there is no movement at the fracture site under physiological loads. This leads to **primary bone healing** (direct cortical remodeling without callus formation). **Eccentric compression plating** (Option C) achieves this by utilizing the "tension band principle" or specialized plate holes (like the Dynamic Compression Plate) to exert active pressure across the fracture ends, resulting in absolute stability. **Why the other options are incorrect:** * **Direct interdental wiring (Option A):** This provides only **non-rigid** fixation. It stabilizes the teeth but does not provide enough compression or stability to prevent micro-motion at the bone level. * **Miniplates osteosynthesis (Option B):** These provide **semi-rigid** (functionally stable) fixation. They are designed to neutralize forces along the lines of tension (Champy’s lines) but allow for some microscopic movement, usually leading to secondary bone healing with callus. * **Intermaxillary fixation (Option D):** This is a form of **conservative/indirect** stabilization. While it immobilizes the jaw, it does not provide internal rigid compression at the fracture interface. **High-Yield Clinical Pearls for NEET-PG:** * **Primary Bone Healing:** Requires absolute stability (e.g., Compression plates, Lag screws). No callus is seen on X-ray. * **Secondary Bone Healing:** Occurs with relative stability (e.g., IM nails, Casts, External fixators). Callus formation is visible. * **Gold Standard for Mandible:** While miniplates are the most common clinical practice (load-sharing), **compression plates** (load-bearing) are the classic answer for "rigid fixation." * **Absolute Stability Rule:** Always remember: "Compression = Absolute Stability = Primary Healing."

Q: The most serious complication of a pelvic fracture is:

Hypovolemic shock. ### Explanation **Correct Answer: C. Hypovolemic shock** **Why it is correct:** Pelvic fractures, particularly high-energy "open book" or unstable fractures, are associated with massive internal hemorrhage. The pelvis is a highly vascular area containing the **presacral venous plexus** and the **internal iliac arteries**. A fracture can increase the pelvic volume significantly, allowing for the sequestration of up to 4 liters of blood (nearly the entire circulating volume) within the retroperitoneal space. **Hemorrhagic (hypovolemic) shock** is the leading cause of early mortality in these patients, making it the most serious and life-threatening complication. **Why the other options are incorrect:** * **A. Rupture of the urinary bladder:** While urogenital injuries (bladder or urethral rupture) are common in pelvic trauma, they are rarely immediately life-threatening compared to massive hemorrhage. * **B. Neurogenic shock:** This typically occurs in spinal cord injuries due to loss of sympathetic tone. While pelvic fractures can cause nerve root injuries (e.g., sacral plexus), they do not typically cause neurogenic shock. * **D. Malunion:** This is a late/delayed complication. While it leads to chronic pain and gait abnormalities, it does not pose an immediate threat to the patient's life. **High-Yield Clinical Pearls for NEET-PG:** * **Source of Bleeding:** 80–90% of hemorrhage in pelvic fractures is **venous** (Presacral plexus), while 10–20% is arterial (Internal iliac artery branches, most commonly the **Superior Gluteal Artery**). * **Initial Management:** The first step in stabilizing an unstable pelvic fracture in the ER is the application of a **Pelvic Binder** (at the level of the greater trochanters) to decrease pelvic volume and provide tamponade. * **Associated Injury:** The most common site of urethral injury in pelvic fractures is the **membranous urethra** (at the puboprostatic junction).

Question 1

Russell's traction is indicated for which of the following conditions?

Accepted Answer

Inter-trochanteric fracture

Answer

Fracture of the shaft of femur

Answer

Low back ache

Answer

Flexion deformity of the hip

Question 2

Which nerve repair has the worst prognosis?

Accepted Answer

Lateral popliteal

Answer

Ulnar

Answer

Radial

Answer

Median

Question 3

Axillary nerve injury is most likely to be seen in which of the following conditions?

Accepted Answer

Shoulder dislocation

Answer

Coracoid process fracture

Answer

Humerus shaft fracture

Answer

Brachial plexus injury

Question 4

If an adolescent boy falls on an outstretched hand, which is the most common bone to be injured?

Accepted Answer

Scaphoid fracture

Answer

Fracture of the lower end of the radius

Answer

Fracture of both bones of the forearm

Answer

Supracondylar fracture of the humerus

Question 5

Pointing index in a supracondylar fracture is due to which nerve injury?

Accepted Answer

Anterior interosseous nerve

Answer

Radial nerve

Answer

Ulnar nerve

Answer

Musculocutaneous nerve

Question 6

Which traumatic fracture is most likely to show avascular necrosis?

Accepted Answer

Femoral neck

Answer

Surgical neck of humerus

Answer

Body of talus

Answer

Cuboid

Question 7

Pipkin fracture is defined as:

Accepted Answer

Head of femur fracture

Answer

Head of radius fracture

Answer

Fracture dislocation of ankle

Answer

Fracture neck of femur

Question 8

Which treatment plan would lead to rigid fixation of the fracture site?

Accepted Answer

Eccentric compression plate osteosynthesis

Answer

Direct interdental wiring

Answer

Miniplates osteosynthesis

Answer

Intermaxillary fixation (IMF)

Question 9

A Hoffa fracture is defined as:

Accepted Answer

Coronal fracture of the posterior part of the femoral condyles

Answer

Stellate patella fracture

Answer

Metaphyseo-diaphyseal dissociation of the proximal tibia

Answer

Medial collateral ligament avulsion from the femur

Question 10

The most serious complication of a pelvic fracture is:

Accepted Answer

Hypovolemic shock

Answer

Rupture of the urinary bladder

Answer

Neurogenic shock

Answer

Malunion

Trauma — MCQs

Trauma — MCQs

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