NEET-PG 2013 — Orthopaedics
38 Previous Year Questions with Answers & Explanations
True about proximal fragment in subtrochanteric fracture is?
Pilon fracture is
Which of the following is NOT a complication of elbow dislocation?
In an extension type of supracondylar fracture, what is the usual direction of displacement?
Which type of supracondylar fracture of the femur is classified as extra-articular?
What is a late complication of elbow dislocation?
What is the most common type of shoulder dislocation?
Most commonly recommended cast position for proximal forearm fractures is ?
What is the Essex-Lopresti lesion in the upper limb?
Whiplash injury is a tear of which ligament?
NEET-PG 2013 - Orthopaedics NEET-PG Practice Questions and MCQs
Question 1: True about proximal fragment in subtrochanteric fracture is?
- A. Flexion
- B. Abduction
- C. External rotation
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** - In a subtrochanteric fracture, the **proximal fragment** is under the influence of several strong muscle groups, leading to a characteristic displacement. - The **iliopsoas muscle** causes **flexion**, the **gluteus medius and minimus** cause **abduction**, and the **short external rotators** cause **external rotation**. *Flexion* - The powerful **iliopsoas muscle** inserts on the lesser trochanter and acts to flex the hip. - This muscle pulls the proximal fragment anteriorly and superiorly, resulting in a **flexion deformity**. *Abduction* - The **gluteus medius and minimus muscles** attach to the greater trochanter and exert a strong abducting force. - This action pulls the proximal fragment away from the midline, causing **abduction**. *External rotation* - The **short external rotators** (e.g., piriformis, obturators, gemelli) insert around the greater trochanter. - These muscles collectively cause the proximal fragment to rotate outwards, resulting in **external rotation**.
Question 2: Pilon fracture is
- A. Bimalleolar fracture
- B. Trimalleolar fracture
- C. Distal tibia Intraarticular fracture (Correct Answer)
- D. Proximal tibia fracture
Explanation: ***Distal tibia Intraarticular fracture*** - A **pilon fracture** specifically refers to an **intra-articular fracture of the distal tibia**, involving the weight-bearing surface of the **ankle joint**. - These fractures typically result from high-energy axial loading mechanisms, driving the talus into the plafond and causing extensive articular damage. *Bimalleolar fracture* - A **bimalleolar fracture** involves fractures of both the **medial malleolus** (distal tibia) and the **lateral malleolus** (distal fibula). - While it involves the ankle, it does not necessarily involve the **tibial plafond** articular surface in the same destructive manner as a pilon fracture. *Trimalleolar fracture* - A **trimalleolar fracture** includes fractures of the medial, lateral, and **posterior malleolus** (a portion of the distal tibia). - Like bimalleolar fractures, it primarily describes the involvement of the malleoli rather than the intra-articular surface load-bearing portion of the distal tibia. *Proximal tibia fracture* - This term refers to a fracture occurring in the **upper part of the tibia**, near the knee joint. - It does not involve the **distal end of the tibia** or the ankle joint, which is characteristic of a pilon fracture.
Question 3: Which of the following is NOT a complication of elbow dislocation?
- A. Vascular injury
- B. Median nerve injury
- C. Myositis ossificans
- D. Radial nerve injury (Correct Answer)
Explanation: ***Radial nerve injury*** - The **radial nerve** is rarely injured in an elbow dislocation due to its anatomical course, which is less exposed to the shearing forces involved in this type of injury. - While other nerves like the ulnar and median nerves are more susceptible, significant stretching or compression of the radial nerve is **uncommon** in typical elbow dislocations. *Vascular injury* - The **brachial artery** runs in close proximity to the elbow joint and can be torn or compressed during a dislocation, leading to **ischemia** if not promptly recognized and treated. - This complication can result in **Volkmann's ischemic contracture** if perfusion is not restored. *Median nerve injury* - The **median nerve** passes anterior to the elbow joint and is vulnerable to injury from stretching or direct compression during dislocation. - Injury can manifest as **sensory deficits** in the distribution of the median nerve and **weakness** of forearm pronation and thumb flexion/opposition. *Myositis ossificans* - This is a common chronic complication of elbow dislocations, particularly in cases of **delayed reduction** or aggressive physical therapy. - It involves the **abnormal ossification** of soft tissues around the joint, commonly in the brachialis muscle, leading to **pain and restricted range of motion**.
Question 4: In an extension type of supracondylar fracture, what is the usual direction of displacement?
- A. Posterolateral (Correct Answer)
- B. Anteromedial
- C. Anterolateral
- D. Posteromedial
Explanation: ***Posterolateral*** - In an **extension type supracondylar fracture**, the distal fragment (forearm and hand) is typically displaced **posteriorly and laterally**. - This common displacement pattern is often caused by a **fall on an outstretched hand** with the elbow in extension, forcing the olecranon against the humerus. *Anteromedial* - This is an **uncommon displacement** in supracondylar fractures and is not characteristic of the extension type. - While displacement can have a medial or lateral component, the primary displacement in extension type is posterior. *Anterolateral* - Displacement in an anterior direction is typically seen in **flexion-type supracondylar fractures**, which are much rarer. - Even in flexion-type fractures, the lateral component of displacement is less common than medial. *Posteromedial* - While posterior displacement is characteristic of extension supracondylar fractures, a **posteromedial displacement** is encountered, but **posterolateral** is the *most common* pattern. - The varus force often involved in these injuries tends to promote lateral displacement of the distal fragment.
Question 5: Which type of supracondylar fracture of the femur is classified as extra-articular?
- A. Type B
- B. Type C
- C. Type A (Correct Answer)
- D. Type D
Explanation: ***Type A*** - **Type A supracondylar fractures** are defined as those that do not involve the joint surface, making them **extra-articular**. - These fractures typically occur proximal to the condyles without extending into the knee articulation. *Type B* - **Type B supracondylar fractures** are considered **partial articular**, meaning they involve only a portion of the articular surface. - While they affect the joint, they are not completely intra-articular in nature. *Type C* - **Type C supracondylar fractures** are classified as **complete articular** fractures. - This type implies that the fracture line extends through the entire joint surface and separates the articular segment from the metaphysis. *Type D* - The classification of supracondylar femoral fractures generally uses A, B, and C types to denote extra-articular, partial articular, and complete articular involvement, respectively. - **Type D** is not a standard classification used to define an extra-articular supracondylar femoral fracture in common orthopedic systems like the Orthopaedic Trauma Association (OTA) classification.
Question 6: What is a late complication of elbow dislocation?
- A. Median nerve injury
- B. Brachial artery injury
- C. Myositis ossificans (Correct Answer)
- D. None of the options
Explanation: **Myositis ossificans** - **Myositis ossificans** is the abnormal formation of **heterotopic bone** within muscle or other soft tissues, often developing weeks to months after joint trauma such as an elbow dislocation. - It typically presents as a painful, firm mass with restricted joint movement, especially **flexion** and **extension** at the elbow. *Median nerve injury* - **Median nerve injury** can occur at the time of the initial elbow dislocation (an **acute complication**), but it is not typically considered a late complication that develops over weeks or months. - Symptoms include numbness in the thumb, index, and middle fingers, as well as weakness in **thumb opposition** and **flexion** of the index finger. *Brachial artery injury* - **Brachial artery injury** is an **acute complication** of severe elbow dislocation, leading to compromise of distal blood flow. - Signs include absence of pulses, pallor, paresthesia, and pain in the forearm and hand, requiring immediate surgical intervention. *None of the options* - This option is incorrect because **myositis ossificans** is a well-recognized late complication of elbow dislocation.
Question 7: What is the most common type of shoulder dislocation?
- A. Subcoracoid
- B. Subclavicular
- C. Posterior
- D. Anterior (Correct Answer)
Explanation: ***Anterior*** - **Anterior shoulder dislocations** account for more than 95% of all shoulder dislocations due to the anatomical vulnerability created by the lack of structural support anteriorly. - The **humeral head** displaces anteriorly and inferiorly relative to the glenoid, often resulting from **abduction and external rotation** forces. *Subcoracoid* - **Subcoracoid dislocation** is a specific type of **anterior dislocation** where the humeral head specifically lies inferior to the coracoid process. - While it is a common presentation of anterior dislocation, "anterior" refers to the broader category and hence is the more encompassing and correct answer. *Subclavicular* - **Subclavicular dislocation** is an even rarer type of **anterior dislocation** where the humeral head is displaced medially, lying inferior to the clavicle. - This is a much less common variant compared to general anterior dislocations. *Posterior* - **Posterior shoulder dislocations** are rare, accounting for only 2-4% of all shoulder dislocations. - They are typically associated with specific mechanisms like **seizures**, **electric shock**, or a fall on an adducted, internally rotated arm.
Question 8: Most commonly recommended cast position for proximal forearm fractures is ?
- A. Pronated flexion
- B. Neutral position
- C. Supinated position (Correct Answer)
- D. Position does not matter
Explanation: ***Supinated position*** - The **supinated position** is generally recommended for proximal forearm fractures because the **biceps brachii** and **supinator muscles**, which are often attached to the proximal fracture segment, cause **supination** when they contract. - Placing the forearm in supination **aligns the distal fracture fragment** with the proximal fragment, promoting better reduction and healing. *Pronated flexion* - **Pronation** would cause the distal fragment to rotate away from the proximal fragment, leading to **malunion** or nonunion. - While some fractures might benefit from a degree of flexion, **pronated flexion** specifically is not the primary position for proximal forearm alignment. *Neutral position* - A **neutral position** might not adequately account for the rotational forces exerted by the biceps and supinator on the proximal fragment, potentially leading to **rotational displacement**. - It does not offer the same alignment benefits as full supination for most proximal forearm fractures. *Position does not matter* - The **cast position is crucial** for forearm fractures, especially proximal ones, as the muscles attached to the forearm bones exert significant rotational forces. - An **incorrect cast position** can lead to rotational deformities, **malunion**, and functional impairment of the forearm.
Question 9: What is the Essex-Lopresti lesion in the upper limb?
- A. Isolated radial head fracture without soft tissue involvement
- B. Radial shaft
- C. Comminuted radial head fracture with interosseous membrane disruption and DRUJ instability (Correct Answer)
- D. Radial shaft and radio-ulnar joint fracture
Explanation: ***Comminuted radial head fracture with interosseous membrane disruption and DRUJ instability*** - The Essex-Lopresti lesion is a severe injury characterized by a **comminuted radial head fracture**, **disruption of the interosseous membrane** (IOM), and eventual **distal radioulnar joint (DRUJ) instability**. - This complex injury can lead to significant **forearm instability**, pain, and loss of function due to the disruption of the forearm's longitudinal stability. *Isolated radial head fracture without soft tissue involvement* - This describes a less severe injury, typically classified as a **Mason type I or II radial head fracture**, where the soft tissue structures like the interosseous membrane and DRUJ are intact. - An isolated radial head fracture lacks the characteristic **longitudinal instability** of the Essex-Lopresti lesion, which is critical for its diagnosis. *Radial shaft* - A radial shaft fracture involves the **diaphysis of the radius** and is a different type of injury that does not inherently include a radial head fracture or interosseous membrane disruption as seen in Essex-Lopresti. - While a radial shaft fracture can occur, it's typically a **more localized injury** to the shaft itself and does not define the systemic instability of an Essex-Lopresti lesion. *Radial shaft and radio-ulnar joint fracture* - This description is vague and does not specifically capture the key components of an Essex-Lopresti injury which include the **radial head fracture**, **interosseous membrane disruption**, and resultant **DRUJ instability**. - A fracture of the radio-ulnar joint could refer to several different types of injuries but without mentioning the comminuted radial head fracture and interosseous membrane disruption, it misses the precise definition of an Essex-Lopresti lesion.
Question 10: Whiplash injury is a tear of which ligament?
- A. Ligamenta flava
- B. Supraspinal ligament
- C. Post. longitudinal ligament (Correct Answer)
- D. Anterior longitudinal ligament
Explanation: ***Post. longitudinal ligament*** - Whiplash injury, often caused by **hyperextension-hyperflexion** of the cervical spine, commonly results in a tear of the **posterior longitudinal ligament**. - This ligament is crucial for stabilizing the spine and preventing **hyperflexion**, making it vulnerable during sudden, forceful movements. *Ligamenta flava* - The **ligamenta flava** are located on the posterior aspect of the vertebral canal and are primarily composed of elastic tissue, providing flexibility. - While they can be injured in severe trauma, they are less commonly implicated in typical whiplash compared to the **posterior longitudinal ligament**. *Anterior longitudinal ligament* - The **anterior longitudinal ligament** is primarily involved in preventing **hyperextension** of the spine. - While it can be injured in whiplash, the hyperextension phase typically stresses this ligament, but the hyperflexion rebound phase is more damaging to posterior structures. *Supraspinal ligament* - The **supraspinal ligament** connects the tips of the spinous processes and primarily limits **flexion** of the spine. - While it can be strained during whiplash, it is not the primary ligament commonly torn in typical whiplash injuries, which often involve deeper spinal ligaments.