NEET-PG 2019 — Orthopaedics

Q: Which part of scaphoid fracture is most susceptible to avascular necrosis?

Proximal 1/3rd. ***Proximal 1/3rd*** - The **scaphoid bone** has a **retrograde blood supply**, meaning blood vessels enter distally and flow towards the proximal pole. - A fracture in the **proximal 1/3rd** can disrupt the blood supply to the **proximal fragment**, making it highly susceptible to **avascular necrosis**. *Distal 1/3rd* - Fractures in the **distal 1/3rd** of the scaphoid generally have a robust blood supply due to the entry of vessels from the distal pole. - While still requiring proper management, the risk of **avascular necrosis** is significantly lower compared to proximal fractures. *Middle 1/3rd* - Fractures in the **middle 1/3rd** (waist) of the scaphoid are common and can still compromise blood flow to the proximal segment, but the risk of **avascular necrosis** is intermediate. - The more proximal the fracture within the middle third, the higher the risk of **avascular necrosis**. *Scaphoid Tubercle* - The **scaphoid tubercle** is a distal projection of the scaphoid bone. - Fractures of the **scaphoid tubercle** are extra-articular and typically have an excellent blood supply; thus, they are at very low risk for **avascular necrosis**. [Practice more Orthopaedics PYQs on OnCourse]

Q: What should be the most likely diagnosis of this 65-year-old lady who presents with backache?

Spondylolisthesis. ***Spondylolisthesis*** - The lateral X-ray image reveals an **anterior displacement of one vertebral body over the one below it**, which is characteristic of spondylolisthesis. - In a 65-year-old lady, degenerative spondylolisthesis due to **arthritic changes and instability** is a common cause of backache. *Osteoporotic fracture* - An osteoporotic fracture would typically show a **compression deformity** or a wedge-shaped vertebral body, which is not clearly depicted here. - While osteoporosis is common in this age group, the primary finding on this image is vertebral slippage, not fracture. *Spondylolysis* - Spondylolysis is a **defect in the pars interarticularis** (a thin segment of bone connecting the superior and inferior articular facets) and is best seen on oblique views or CT. - Although spondylolysis can *lead to* spondylolisthesis, the immediate and most striking finding on this lateral view is the slippage itself. *Discitis* - Discitis, an **inflammation or infection of the intervertebral disc and adjacent vertebrae**, would typically show **loss of disc height** and **endplate irregularities or erosions**. - These features are not the predominant finding on this image, which clearly demonstrates vertebral body displacement. [Practice more Orthopaedics PYQs on OnCourse]

Q: A 25-year-old male presents with localized pain in the tibia and swelling. Imaging reveals a bone abscess. Identify the condition.

Brodie abscess. ***Brodie abscess*** - A Brodie abscess is a **subacute or chronic osteomyelitis** characterized by a well-circumscribed, **radiolucent lesion** (an abscess cavity) often surrounded by a zone of **sclerosis**, representing the body's attempt to wall off the infection. - The presentation of localized pain and swelling in the tibia, with imaging revealing a bone abscess, is consistent with this condition, which is a common form of localized osteomyelitis. *Osteoid osteoma* - This is a **benign bone tumor** characterized by a small, radiolucent nidus surrounded by a large area of **sclerotic bone**. The pain from an osteoid osteoma is typically **worse at night** and dramatically relieved by NSAIDs. - While it can cause localized pain and swelling, the imaging features of a distinct abscess cavity are not characteristic of an osteoid osteoma. *Intracortical hemangioma* - An intracortical hemangioma is a **rare benign vascular lesion** within the cortex of a bone. - Imaging typically shows a **lytic lesion** with a characteristic **"honeycomb" or "sunburst" appearance**, not a well-defined abscess. *Chondromyxoid fibroma* - This is a rare, **benign cartilaginous tumor** that usually presents as an **eccentric lytic lesion** in the metaphysis of long bones, often with a scalloped border and sclerotic rim. - While it can cause localized pain and swelling, the imaging appearance of an abscess with sclerotic margins is not typical of a chondromyxoid fibroma. [Practice more Orthopaedics PYQs on OnCourse]

Q: Scaphoid fracture which area has maximum chances of AVN/Non-union/Malunion:-

Proximal 1/3. ***Proximal 1/3*** - The **proximal pole of the scaphoid** has a precarious blood supply, primarily from retrograde extraosseous vessels entering distally. A fracture in this region can compromise this supply, leading to **avascular necrosis (AVN)**. - Due to the limited blood flow to the proximal fragment, healing is often impaired, increasing the risk of **non-union** and **malunion**. *Distal 1/3* - Fractures in the **distal 1/3 (distal pole)** of the scaphoid typically have a better prognosis. - This area has a more robust blood supply, reducing the risk of AVN and promoting faster healing. *Scaphoid Tubercle fracture* - Fractures of the **scaphoid tubercle** are usually considered stable and intra-articular, with a good blood supply. - These fractures generally heal well with conservative treatment and have a very low incidence of AVN or non-union. *Middle 1/3* - Fractures in the **middle 1/3 (waist)** of the scaphoid are the most common but still pose a significant risk of non-union. - While the risk of AVN is lower than for proximal pole fractures, it is still higher than for distal fractures, due to the critical vascular supply to both fragments. [Practice more Orthopaedics PYQs on OnCourse]

Q: 12 years male came with swelling of lower end tibia which is surrounded by rim of reactive bone. What is most likely diagnosis?

Brodie's Abscess. ***Brodie's Abscess*** - A **Brodie's abscess** is a subacute or chronic osteomyelitis characterized by a localized bone abscess, typically with a surrounding **sclerotic rim of reactive bone**. - It often occurs in the **metaphysis of long bones** (like the lower end of the tibia) in children and adolescents, presenting with localized pain and swelling. *GCT* - **Giant cell tumor (GCT)** typically occurs in **skeletally mature adults** (20-40 years old) and is a lytic lesion often found in the **epiphysis** of long bones, rarely with a distinct sclerotic rim. - GCTs are generally more aggressive and demonstrate a **soap-bubble appearance** with cortical expansion rather than a thick reactive bone rim. *Hyper PTH* - **Hyperparathyroidism** causes bone changes such as **osteopenia**, **subperiosteal bone resorption**, especially in the phalanges, and **brown tumors** (lytic lesions). - It does not typically present as a localized lesion with a **sclerotic rim of reactive bone** in a child. *Osteomyelitis* - While chronic osteomyelitis can involve local bone destruction and reactive bone formation, a **Brodie's abscess** is a specific, well-circumscribed form of **subacute osteomyelitis**. - Acute osteomyelitis presents with more diffuse systemic symptoms (fever, malaise) and less defined reactive bone in its early stages compared to the distinct **sclerotic rim** seen in a Brodie's abscess. [Practice more Orthopaedics PYQs on OnCourse]

6 Previous Year Questions with Answers & Explanations

Questions

Which part of scaphoid fracture is most susceptible to avascular necrosis?

What should be the most likely diagnosis of this 65-year-old lady who presents with backache?

A 25-year-old male presents with localized pain in the tibia and swelling. Imaging reveals a bone abscess. Identify the condition.

Scaphoid fracture which area has maximum chances of AVN/Non-union/Malunion:-

12 years male came with swelling of lower end tibia which is surrounded by rim of reactive bone. What is most likely diagnosis?

A patient with GCT, which of the following is false?

NEET-PG 2019 - Orthopaedics NEET-PG Practice Questions and MCQs

Question 1: Which part of scaphoid fracture is most susceptible to avascular necrosis?

A. Distal 1/3rd
B. Middle 1/3rd
C. Proximal 1/3rd (Correct Answer)
D. Scaphoid Tubercle

Explanation: ***Proximal 1/3rd*** - The **scaphoid bone** has a **retrograde blood supply**, meaning blood vessels enter distally and flow towards the proximal pole. - A fracture in the **proximal 1/3rd** can disrupt the blood supply to the **proximal fragment**, making it highly susceptible to **avascular necrosis**. *Distal 1/3rd* - Fractures in the **distal 1/3rd** of the scaphoid generally have a robust blood supply due to the entry of vessels from the distal pole. - While still requiring proper management, the risk of **avascular necrosis** is significantly lower compared to proximal fractures. *Middle 1/3rd* - Fractures in the **middle 1/3rd** (waist) of the scaphoid are common and can still compromise blood flow to the proximal segment, but the risk of **avascular necrosis** is intermediate. - The more proximal the fracture within the middle third, the higher the risk of **avascular necrosis**. *Scaphoid Tubercle* - The **scaphoid tubercle** is a distal projection of the scaphoid bone. - Fractures of the **scaphoid tubercle** are extra-articular and typically have an excellent blood supply; thus, they are at very low risk for **avascular necrosis**.

Question 2: What should be the most likely diagnosis of this 65-year-old lady who presents with backache?

A. Osteoporotic fracture
B. Spondylolisthesis (Correct Answer)
C. Spondylolysis
D. Discitis

Explanation: ***Spondylolisthesis*** - The lateral X-ray image reveals an **anterior displacement of one vertebral body over the one below it**, which is characteristic of spondylolisthesis. - In a 65-year-old lady, degenerative spondylolisthesis due to **arthritic changes and instability** is a common cause of backache. *Osteoporotic fracture* - An osteoporotic fracture would typically show a **compression deformity** or a wedge-shaped vertebral body, which is not clearly depicted here. - While osteoporosis is common in this age group, the primary finding on this image is vertebral slippage, not fracture. *Spondylolysis* - Spondylolysis is a **defect in the pars interarticularis** (a thin segment of bone connecting the superior and inferior articular facets) and is best seen on oblique views or CT. - Although spondylolysis can *lead to* spondylolisthesis, the immediate and most striking finding on this lateral view is the slippage itself. *Discitis* - Discitis, an **inflammation or infection of the intervertebral disc and adjacent vertebrae**, would typically show **loss of disc height** and **endplate irregularities or erosions**. - These features are not the predominant finding on this image, which clearly demonstrates vertebral body displacement.

Question 3: A 25-year-old male presents with localized pain in the tibia and swelling. Imaging reveals a bone abscess. Identify the condition.

A. Brodie abscess (Correct Answer)
B. Osteoid osteoma
C. Intracortical hemangioma
D. Chondromyxoid fibroma

Explanation: ***Brodie abscess*** - A Brodie abscess is a **subacute or chronic osteomyelitis** characterized by a well-circumscribed, **radiolucent lesion** (an abscess cavity) often surrounded by a zone of **sclerosis**, representing the body's attempt to wall off the infection. - The presentation of localized pain and swelling in the tibia, with imaging revealing a bone abscess, is consistent with this condition, which is a common form of localized osteomyelitis. *Osteoid osteoma* - This is a **benign bone tumor** characterized by a small, radiolucent nidus surrounded by a large area of **sclerotic bone**. The pain from an osteoid osteoma is typically **worse at night** and dramatically relieved by NSAIDs. - While it can cause localized pain and swelling, the imaging features of a distinct abscess cavity are not characteristic of an osteoid osteoma. *Intracortical hemangioma* - An intracortical hemangioma is a **rare benign vascular lesion** within the cortex of a bone. - Imaging typically shows a **lytic lesion** with a characteristic **"honeycomb" or "sunburst" appearance**, not a well-defined abscess. *Chondromyxoid fibroma* - This is a rare, **benign cartilaginous tumor** that usually presents as an **eccentric lytic lesion** in the metaphysis of long bones, often with a scalloped border and sclerotic rim. - While it can cause localized pain and swelling, the imaging appearance of an abscess with sclerotic margins is not typical of a chondromyxoid fibroma.

Question 4: Scaphoid fracture which area has maximum chances of AVN/Non-union/Malunion:-

A. Distal 1/3
B. Proximal 1/3 (Correct Answer)
C. Scaphoid Tubercle fracture
D. Middle 1/3

Explanation: ***Proximal 1/3*** - The **proximal pole of the scaphoid** has a precarious blood supply, primarily from retrograde extraosseous vessels entering distally. A fracture in this region can compromise this supply, leading to **avascular necrosis (AVN)**. - Due to the limited blood flow to the proximal fragment, healing is often impaired, increasing the risk of **non-union** and **malunion**. *Distal 1/3* - Fractures in the **distal 1/3 (distal pole)** of the scaphoid typically have a better prognosis. - This area has a more robust blood supply, reducing the risk of AVN and promoting faster healing. *Scaphoid Tubercle fracture* - Fractures of the **scaphoid tubercle** are usually considered stable and intra-articular, with a good blood supply. - These fractures generally heal well with conservative treatment and have a very low incidence of AVN or non-union. *Middle 1/3* - Fractures in the **middle 1/3 (waist)** of the scaphoid are the most common but still pose a significant risk of non-union. - While the risk of AVN is lower than for proximal pole fractures, it is still higher than for distal fractures, due to the critical vascular supply to both fragments.

Question 5: 12 years male came with swelling of lower end tibia which is surrounded by rim of reactive bone. What is most likely diagnosis?

A. GCT
B. Hyper PTH
C. Brodie's Abscess (Correct Answer)
D. Osteomyelitis

Explanation: ***Brodie's Abscess*** - A **Brodie's abscess** is a subacute or chronic osteomyelitis characterized by a localized bone abscess, typically with a surrounding **sclerotic rim of reactive bone**. - It often occurs in the **metaphysis of long bones** (like the lower end of the tibia) in children and adolescents, presenting with localized pain and swelling. *GCT* - **Giant cell tumor (GCT)** typically occurs in **skeletally mature adults** (20-40 years old) and is a lytic lesion often found in the **epiphysis** of long bones, rarely with a distinct sclerotic rim. - GCTs are generally more aggressive and demonstrate a **soap-bubble appearance** with cortical expansion rather than a thick reactive bone rim. *Hyper PTH* - **Hyperparathyroidism** causes bone changes such as **osteopenia**, **subperiosteal bone resorption**, especially in the phalanges, and **brown tumors** (lytic lesions). - It does not typically present as a localized lesion with a **sclerotic rim of reactive bone** in a child. *Osteomyelitis* - While chronic osteomyelitis can involve local bone destruction and reactive bone formation, a **Brodie's abscess** is a specific, well-circumscribed form of **subacute osteomyelitis**. - Acute osteomyelitis presents with more diffuse systemic symptoms (fever, malaise) and less defined reactive bone in its early stages compared to the distinct **sclerotic rim** seen in a Brodie's abscess.

Question 6: A patient with GCT, which of the following is false?

A. Defined margins
B. Chemotherapy is the mainstay of treatment (Correct Answer)
C. Epiphyseo-metaphyseal location
D. Eccentric

Explanation: ***Chemotherapy is the mainstay of treatment*** - This statement is **false** because **Giant Cell Tumor of Bone (GCT)** therapy primarily involves **surgical resection**, with or without adjuvant therapies like **denosumab**. - **Chemotherapy** is generally *not* the first-line treatment for GCT, as these tumors respond poorly to it; it's usually reserved for cases of **metastatic GCT** or when other treatments fail. *Defined margins* - GCTs often present radiographically with **well-defined, non-sclerotic margins**, which indicates a lytic lesion that is often locally aggressive but typically doesn't invade widely. - While they are locally destructive, their borders are usually visible, helping distinguish them from other bone tumors. *Epiphyseo-metaphyseal location* - GCTs commonly originate in the **metaphysis** of long bones and **extend into the epiphysis** after the growth plate has closed. - This characteristic location near a joint is a classic diagnostic feature of GCT, especially in adults. *Eccentric* - GCTs typically arise **eccentrically** within the bone, meaning they originate off-center in the bone marrow cavity before expanding and thinning the cortex. - This eccentric growth pattern is a distinguishing feature, particularly in contrast to other bone tumors which might be centrally located.