Trauma Practice Questions

Q: Tardy ulnar nerve palsy is caused by which of the following?

Fracture of the lateral epicondyle of the humerus. **Explanation:** **Tardy Ulnar Nerve Palsy** is a delayed-onset neuropathy that occurs years after an elbow injury. The primary mechanism is **Cubitus Valgus** (increased carrying angle). **Why Option A is Correct:** The most common cause is a non-union of a **fracture of the lateral epicondyle** (or lateral condyle) of the humerus sustained in childhood. When the lateral condyle fails to unite, the lateral side of the distal humerus stops growing while the medial side continues. This leads to a progressive **Cubitus Valgus deformity**. This deformity stretches the ulnar nerve as it travels behind the medial epicondyle, leading to chronic friction and eventual palsy. **Why Other Options are Incorrect:** * **B. Fracture of the medial epicondyle:** While this can cause *acute* ulnar nerve injury (due to its proximity), it does not typically result in the progressive valgus deformity required for "tardy" (delayed) palsy. * **C. Elbow dislocation:** This usually results in acute nerve injuries (most commonly the median or ulnar nerve) rather than a delayed presentation years later. * **D. Supracondylar fracture:** This is the most common pediatric elbow fracture. It typically leads to **Cubitus Varus** (Gunstock deformity) if malunited. Cubitus varus does not stretch the ulnar nerve; in fact, it may occasionally lead to tardy *posterolateral instability* but not classic tardy ulnar palsy. **Clinical Pearls for NEET-PG:** * **Latency:** The symptoms (wasting of intrinsic hand muscles, clawing) usually appear **10–20 years** after the initial injury. * **Deformity:** Always associate Tardy Ulnar Nerve Palsy with **Cubitus Valgus**. * **Treatment:** The procedure of choice is **Anterior Transposition of the Ulnar Nerve**, where the nerve is moved from its posterior groove to the front of the medial epicondyle to relieve tension.

Q: Which of the following is NOT a type of displacement seen in a Colles fracture?

Ventral tilt. A **Colles fracture** is a distal radius fracture occurring within 2.5 cm of the wrist joint, typically resulting from a fall on an outstretched hand (FOOSH). The hallmark of this fracture is the **dorsal (posterior)** displacement of the distal fragment, which creates the classic "Dinner Fork Deformity." ### Why "Ventral Tilt" is the Correct Answer: In a Colles fracture, the distal fragment tilts **dorsally** (backwards). A **ventral (volar/anterior) tilt** is the defining characteristic of a **Smith’s fracture**, often referred to as a "Reverse Colles." Therefore, ventral tilt is NOT seen in a Colles fracture. ### Explanation of Incorrect Options: The distal fragment in a Colles fracture typically undergoes six types of displacement: * **Dorsal Tilt (Option A):** The articular surface faces posteriorly instead of its normal slight volar tilt. * **Dorsal Displacement (Option C):** The fragment moves toward the back of the hand. * **Lateral Displacement (Option D):** The fragment moves toward the radial side. * *Other displacements include:* Lateral tilt (radial tilt), impaction, and supination. ### High-Yield Clinical Pearls for NEET-PG: * **Deformity:** Dinner fork deformity (due to dorsal displacement). * **Smith’s Fracture:** Garden spade deformity (due to ventral displacement). * **Barton’s Fracture:** Intra-articular fracture-dislocation of the wrist (can be dorsal or volar). * **Chauffeur’s Fracture:** Intra-articular fracture of the radial styloid process. * **Complication:** The most common late complication of a Colles fracture is **Malunion**; the most common tendon involved is the **Extensor Pollicis Longus (EPL) rupture**.

Q: What is a bumper fracture?

Fracture of lateral tibial plateau. ### Explanation **1. Why the Correct Answer is Right:** A **Bumper Fracture** (also known as a Fender fracture) refers to a fracture of the **lateral tibial plateau**. It occurs due to a high-energy **valgus strain** (force applied to the lateral side of the knee). The name originates from a classic mechanism of injury: a pedestrian being struck by the front bumper of a car. When the bumper hits the lateral aspect of the knee, the femur acts as a hammer, driving the lateral femoral condyle into the softer articular surface of the lateral tibial plateau, causing a crush or split fracture. **2. Why the Incorrect Options are Wrong:** * **A. Fracture of fibula:** While the neck of the fibula may be fractured simultaneously due to direct impact, the term "Bumper fracture" specifically refers to the intra-articular tibial plateau injury. * **B. Fracture of distal tibia:** Fractures of the distal tibia (near the ankle) are known as **Pilon fractures** (axial loading) or **Pott’s fractures** (malleolar injuries). * **C. Fracture of medial tibial plateau:** Medial plateau fractures are less common and usually result from a **varus** force. They are often associated with higher energy and more severe ligamentous damage. **3. Clinical Pearls for NEET-PG:** * **Classification:** Tibial plateau fractures are classified using the **Schatzker Classification** (Type II is the most common: split + depression of the lateral plateau). * **Associated Injury:** Always check for **Peroneal nerve** injury (foot drop) and **Lateral Collateral Ligament (LCL)** tears. * **Complication:** The most common early complication is **Compartment Syndrome**; the most common late complication is **Secondary Osteoarthritis**. * **Imaging:** CT scan is the gold standard for preoperative planning to assess the degree of articular depression.

Q: A 62-year-old woman presents with a 3-month history of progressive right shoulder pain, limiting her ability to lift her arm for daily activities. She denies neurological symptoms. Physical examination reveals weakness in abduction and external rotation with a normal passive range of motion. She cannot maintain 90 degrees of abduction. There is no motor deficit in the forearm or hand, and pulses and sensation are normal. Which of the following muscles constitute the injured structure?

Supraspinatus, infraspinatus, teres minor, subscapularis. **Explanation:** The clinical presentation describes a classic case of a **Rotator Cuff Tear**. The patient exhibits the "Drop Arm Sign" (inability to maintain 90 degrees of abduction) and weakness in external rotation, while maintaining a normal passive range of motion. This dissociation between active and passive movement is hallmark for a tendon/muscle tear rather than adhesive capsulitis (where both are restricted). The **Rotator Cuff** is a functional unit of four muscles that stabilize the glenohumeral joint. The correct anatomical components are: 1. **Supraspinatus:** Initiates abduction (0-15°). 2. **Infraspinatus:** Primary external rotator. 3. **Teres Minor:** External rotator and adductor. 4. **Subscapularis:** Primary internal rotator. **Analysis of Options:** * **Option D (Correct):** Correctly identifies the four SITS muscles (Supraspinatus, Infraspinatus, Teres minor, Subscapularis). * **Options A & B:** Incorrect because they include the **Teres Major**. While the Teres Major helps in adduction and internal rotation, it is *not* part of the rotator cuff. * **Options A & C:** Incorrect because they include the **Deltoid**. The deltoid is the primary abductor of the arm (after 15°) but is a superficial muscle, not part of the stabilizing rotator cuff. **High-Yield NEET-PG Pearls:** * **Most common muscle injured:** Supraspinatus (due to its location under the acromion). * **Investigation of Choice:** MRI is the gold standard for diagnosing rotator cuff tears. * **Clinical Tests:** Jobe’s Test (Empty Can) for Supraspinatus; Hornblower’s Sign for Teres Minor; Lift-off/Gerber’s test for Subscapularis. * **Nerve Supply:** Suprascapular nerve (Supra/Infraspinatus), Axillary nerve (Teres minor), Upper and Lower Subscapular nerves (Subscapularis).

Q: Which of the following best describes the patient's wrist fracture?

Colles fracture. ***Colles fracture*** - Affects the **distal radius** with **dorsal displacement** and **dorsal angulation**, creating the characteristic **"dinner fork" deformity** on clinical examination. - Most commonly occurs from a **fall on outstretched hand (FOOSH)** mechanism, particularly in elderly patients with **osteoporosis**. *Bennett's fracture* - This is a fracture-dislocation at the **base of the first metacarpal** (thumb), not involving the wrist or radius. - Requires **surgical fixation** due to instability at the **carpometacarpal joint** of the thumb. *Jones fracture* - Occurs at the **5th metatarsal** in the **foot**, specifically at the **metaphyseal-diaphyseal junction**. - Has poor healing potential due to **watershed blood supply** and often requires **surgical intervention**. *Salter-Harris fracture* - This classification applies to **growth plate injuries** in **pediatric patients** with open physes. - Would not be applicable to typical wrist fractures in adults where **growth plates are closed**.

Q: What is the typical position of the distal fragment in a fracture of the upper third of the femur shaft?

Adducted. In a fracture of the **upper third of the femur shaft**, the displacement of fragments is determined by the powerful muscle groups attached to them. **1. Why Adducted is Correct:** The position of the **distal fragment** is primarily influenced by the **Adductor group of muscles** (Adductor longus, brevis, and magnus). These muscles originate from the pelvis and insert along the linea aspera of the femoral shaft. When the bone is fractured in the upper third, these muscles pull the distal fragment medially, resulting in **Adduction**. **2. Analysis of Other Options:** * **Abducted:** This describes the **proximal fragment**. The proximal fragment is abducted by the Gluteus medius and minimus, and flexed by the Iliopsoas. * **Posteriorly displaced:** While the distal fragment may have some posterior tilt due to the pull of the gastrocnemius (more common in supracondylar fractures), the primary characteristic displacement in upper-third fractures is medial/adduction. * **Anteriorly displaced:** The proximal fragment is the one that appears anteriorly displaced (flexed) due to the Iliopsoas muscle. **High-Yield Clinical Pearls for NEET-PG:** * **Proximal Fragment Position:** Flexed (Iliopsoas), Abducted (Glutei), and Externally Rotated (Short rotators). * **Distal Fragment Position:** Adducted (Adductors) and pulled proximally (Shortening due to Hamstrings and Quadriceps). * **Winquist-Hansen Classification:** Used to grade the comminution of femoral shaft fractures. * **Management:** The gold standard treatment for adult femoral shaft fractures is **Intramedullary (IM) Nailing** (antegrade or retrograde).

Q: All of the following are true about dashboard injuries EXCEPT?

The point of impact is on the greater trochanter.. ### Explanation **1. Why Option D is the Correct Answer (The Exception)** In a **dashboard injury**, the point of impact is **not** the greater trochanter. Instead, the force is applied to the **proximal tibia (knee)** while the hip and knee are flexed (as seen in a seated passenger during a head-on collision). This longitudinal force is transmitted along the shaft of the femur toward the hip joint. Because the hip is flexed and adducted in this position, the femoral head is driven posteriorly, out of the acetabulum. Impact on the greater trochanter is typically associated with lateral compression injuries or femoral neck fractures, not classic dashboard dislocations. **2. Analysis of Other Options** * **Option A:** Dashboard injuries are the classic mechanism for **posterior dislocation of the hip** (the most common type of hip dislocation). * **Option B:** The **sciatic nerve** (specifically the peroneal division) lies immediately posterior to the acetabulum. During a posterior dislocation, the femoral head can compress or stretch the nerve, resulting in **foot drop**. * **Option C:** **Avascular Necrosis (AVN)** is a dreaded late complication. The blood supply to the femoral head (via the retinacular vessels) is disrupted during dislocation. The risk of AVN increases significantly if the dislocation is not reduced within 6 hours. **3. NEET-PG Clinical Pearls** * **Position of the Limb:** In posterior hip dislocation, the limb is typically **shortened, adducted, and internally rotated**. (Contrast this with anterior dislocation: abducted and externally rotated). * **Associated Fracture:** Often associated with a fracture of the **posterior lip of the acetabulum**. * **Management:** It is an **orthopaedic emergency**. The first-line treatment is closed reduction (e.g., Allis maneuver or Bigelow's maneuver) under sedation. * **Most Common Nerve Injured:** Sciatic nerve (10-20% of cases).

Question 1

Tardy ulnar nerve palsy is caused by which of the following?

Accepted Answer

Fracture of the lateral epicondyle of the humerus

Answer

Fracture of the medial epicondyle of the humerus

Answer

Elbow dislocation

Answer

Supracondylar fracture of the humerus

Question 2

Which of the following is NOT a type of displacement seen in a Colles fracture?

Accepted Answer

Ventral tilt

Answer

Dorsal tilt

Answer

Dorsal displacement

Answer

Lateral displacement

Question 3

What is the primary action of an intramedullary 'K' nail?

Accepted Answer

Three-point fixation

Answer

Two-point fixation

Answer

Compression

Answer

Weight concentration

Question 4

An 8-year-old boy falls on a flexed left elbow and suffers a closed, fully displaced flexion type supracondylar fracture. He complains of finger numbness, but will not allow examination of his arm. Which of the following is most likely injured in this fracture?

Accepted Answer

Ulnar nerve

Answer

Anterior interosseous nerve

Answer

Radial nerve

Answer

Radial artery

Question 5

What is a bumper fracture?

Accepted Answer

Fracture of lateral tibial plateau

Answer

Fracture of fibula

Answer

Fracture of distal tibia

Answer

Fracture of medial tibial plateau

Question 6

A 62-year-old woman presents with a 3-month history of progressive right shoulder pain, limiting her ability to lift her arm for daily activities. She denies neurological symptoms. Physical examination reveals weakness in abduction and external rotation with a normal passive range of motion. She cannot maintain 90 degrees of abduction. There is no motor deficit in the forearm or hand, and pulses and sensation are normal. Which of the following muscles constitute the injured structure?

Accepted Answer

Supraspinatus, infraspinatus, teres minor, subscapularis

Answer

Supraspinatus, infraspinatus, teres major, deltoid

Answer

Supraspinatus, infraspinatus, teres major, subscapularis

Answer

Supraspinatus, infraspinatus, teres minor, deltoid

Question 7

Which of the following best describes the patient's wrist fracture?

Accepted Answer

Colles fracture

Answer

Bennett's fracture

Answer

Jones fracture

Answer

Salter-Harris fracture

Question 8

What is the typical position of the distal fragment in a fracture of the upper third of the femur shaft?

Accepted Answer

Adducted

Answer

Abducted

Answer

Posteriorly displaced

Answer

Anteriorly displaced

Question 9

All of the following are true about dashboard injuries EXCEPT?

Accepted Answer

The point of impact is on the greater trochanter.

Answer

It is associated with posterior dislocation of the hip.

Answer

Sciatic nerve may be involved, leading to foot drop.

Answer

Avascular necrosis of the hip could be a late complication.

Question 10

A 55-year-old woman presents with severe pain in the flexor muscles of the forearm, fixed flexion of the fingers, and swelling, cyanosis, and anesthesia of the fingers following a car crash. Which of the following is the most likely diagnosis?

Accepted Answer

Volkmann's ischemic contracture

Answer

Colles' fracture

Answer

Scaphoid fracture

Answer

Bennett's fracture

Trauma — MCQs

Trauma — MCQs

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