Orthopaedics
9 questionsPilon fracture is
What is the most common type of shoulder 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?
Which of the following is NOT a complication of elbow dislocation?
Most commonly recommended cast position for proximal forearm fractures is ?
What is the Essex-Lopresti lesion in the upper limb?
What is the characteristic feature of Barton's fracture?
NEET-PG 2013 - Orthopaedics NEET-PG Practice Questions and MCQs
Question 951: 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 952: 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 953: 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 954: 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 955: 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 956: 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 957: 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 958: 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 959: What is the characteristic feature of Barton's fracture?
- A. Extra-articular fracture of the distal end radius
- B. Intra-articular fracture of the distal end radius without carpal bone subluxation
- C. Intra-articular fracture of the distal end radius with carpal bone subluxation
- D. Intra-articular fracture of the distal end radius with carpal bone subluxation and joint involvement (Correct Answer)
Explanation: ***Intra-articular fracture of the distal end radius with carpal bone subluxation and joint involvement*** - A **Barton's fracture** is defined as an **intra-articular fracture** of the distal radius involving the dorsal or volar rim, accompanied by **subluxation of the carpus**. - The displacement of the **carpal bones** relative to the fractured radius is a hallmark of this injury, necessitating careful reduction for optimal outcome. *Extra-articular fracture of the distal end radius* - An **extra-articular fracture** means the fracture line does not extend into the joint space, which is not characteristic of a Barton's fracture. - Examples of extra-articular distal radius fractures include some types of **Colles' fractures** or **Smith's fractures** without joint involvement. *Intra-articular fracture of the distal end radius without carpal bone subluxation* - While a Barton's fracture is intra-articular, the crucial distinguishing feature is the accompanying **carpal subluxation**. - An **intra-articular fracture** without carpal subluxation would be classified differently, such as a **Chauffeur's fracture** or certain types of **die-punch fractures**. *Intra-articular fracture of the distal end radius with carpal bone subluxation* - This option is partially correct but less complete than the best answer, as it implies joint involvement by definition but doesn't explicitly state it. - The combination of **intra-articular involvement** and **carpal subluxation** explicitly defines a Barton's fracture, whether dorsal or volar.
Pathology
1 questionsIn Articular cartilage, most active chondrocytes are seen in ?
NEET-PG 2013 - Pathology NEET-PG Practice Questions and MCQs
Question 951: In Articular cartilage, most active chondrocytes are seen in ?
- A. Zone 1
- B. Zone 4
- C. Zone 3
- D. Zone 2 (Correct Answer)
Explanation: ***Zone 2*** - This is the **transitional (or middle) zone**, where chondrocytes are numerous and more metabolically active, responsible for synthesizing major components of the extracellular matrix. - Chondrocytes here are typically **ovoid or round**, arranged somewhat randomly, and are involved in maintaining the cartilage structure. *Zone 1* - This is the **superficial (or tangential) zone**, where chondrocytes are **flattened** and oriented parallel to the articular surface. - Their primary role is to resist shear forces, and they are generally less metabolically active compared to those in the transitional zone. *Zone 3* - This is the **deep (or radial) zone**, characterized by **columnar arrangements** of chondrocytes. [1] - While these chondrocytes are metabolically active and synthesize matrix components, they are generally less active than those in the transitional zone and are more involved in resisting compressive forces. *Zone 4* - This is the **calcified zone**, directly adjacent to subchondral bone, where chondrocytes are **sparse** and often hypertrophic prior to eventual calcification. - This zone acts as an interface between cartilage and bone, and its chondrocytes have significantly reduced metabolic activity once calcification occurs. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, p. 1184.