Arthrology and Infections Practice Questions

Q: X-ray appearance of sequestrum?

Radiodense bone fragments. ***Radiodense bone fragments*** - A **sequestrum** refers to a piece of dead bone that has become detached from the surrounding healthy bone, typically due to **osteomyelitis**. - On X-ray, this necrotic bone often appears **denser** (radiodense) than the surrounding viable bone because it has lost its blood supply and can undergo sclerosis, or it simply stands out within the less dense inflammatory exudate. *Osteopenic fragment* - An **osteopenic fragment** would indicate a piece of bone with reduced density, often associated with bone loss or demineralization, which is not characteristic of a sequestrum. - While surrounding bone might appear osteopenic due to infection, the sequestrum itself is typically **denser**. *Fragment with honeycomb loculated appearance* - A **honeycomb or loculated appearance** is typically associated with conditions like fibrous dysplasia, aneurysmal bone cysts, or certain tumors, which involve bone remodeling or cystic changes, not necrotic bone. - This appearance suggests architectural changes within the bone rather than a detached piece of dead bone. *Radiolucent area with speckled calcification* - A **radiolucent area** implies an area of decreased bone density, and when combined with speckled calcifications, it might suggest entities like cartilage tumors (e.g., enchondroma) or certain types of malignant bone tumors. - This description does not fit the characteristic appearance of a **sequestrum**, which is a **dense** bone fragment within a radiolucent area of pus and granulation tissue.

Q: First radiological sign for active tubercular arthritis is?

Localized osteoporosis. ***Localized osteoporosis*** - **Localized osteoporosis** in the juxta-articular region is often the earliest detectable radiological sign in active tubercular arthritis due to **inflammation-induced bone resorption**. - This finding reflects the initial bone changes in response to the **Mycobacterium tuberculosis** infection. *Sclerosis* - **Sclerosis** (increased bone density) in the subchondral bone is typically a feature of chronic or healing arthritis, indicating bone repair and remodeling, which occurs much later than initial inflammation. - It is not an early sign of active disease but rather a response to long-standing stress or infection. *Joint space reduction* - **Joint space reduction** occurs as cartilage is destroyed, which is a relatively later stage in tubercular arthritis, as initial inflammation primarily affects the synovium and juxta-articular bone. - While it is a common radiological finding in many forms of arthritis, it usually follows significant cartilage degradation, thus not being the first sign. *Osteophytes* - **Osteophytes** (bone spurs) are characteristic of degenerative joint disease (osteoarthritis) and represent the body's attempt to stabilize the joint in response to chronic wear and tear or instability. - They are not typically associated with the acute inflammatory process of active tubercular arthritis.

Q: A 20 year old male presents with history of gradual onset pain and swelling in left knee since 6 months. Now since last 1 month patient has started limping while walking and also has flexion deformity of knee. Ultrasonography shows presence of synovial thickening. What is the most probable diagnosis?

Tuberculosis of the knee. ***Tuberculosis of the knee*** - **Gradual onset** of pain, swelling, and **flexion deformity** in the knee, especially in a young male, is highly suggestive of **tuberculosis arthritis**, which is an **insidious chronic monoarthritis**. - **Synovial thickening** on ultrasonography supports inflammation and chronic joint involvement consistent with granulomatous inflammation seen in TB. *Pigmented villonodular synovitis* - This condition is characterized by **hemosiderin deposition** within the synovium, causing painless or minimally painful swelling and recurrent effusions. - While it causes synovial thickening, **flexion deformity** and limping are not typical early features and pain is often less prominent than in TB. *Synovial sarcoma* - Synovial sarcoma is a rare, aggressive **malignant tumor** that can affect soft tissues around joints, leading to pain and swelling. - However, it typically presents as a **palpable soft tissue mass** rather than isolated synovial thickening, and limping with flexion deformity would be a late sign due to mass effect. *Hemarthrosis* - Hemarthrosis is the presence of **blood in the joint space**, usually due to trauma, coagulopathy, or a bleeding disorder. - While it can cause pain and swelling, it is typically of **acute onset** and not associated with gradual progression and chronic flexion deformity unless related to repeated traumatic events.

Q: Deformity of hip in stage of tubercular synovitis?

Flexion, abduction external rotation. ***Flexion, abduction external rotation*** - In the early **synovial stage** of hip tuberculosis, the joint capsule distends due to effusions and inflammation. - This distension pushes the femoral head into a position of maximal comfort, which is typically **flexion, abduction, and external rotation**. *Flexion, adduction internal rotation* - This position, often called the **'telescopic' or 'wandering acetabulum'** deformity, is characteristic of later stages of tubercular hip disease, particularly when bone destruction and subluxation occur. - It results from muscle spasm and destruction of the articular surfaces as the disease progresses, not the initial synovial stage. *Flexion, adduction, external rotation* - While flexion and external rotation might be present in some hip pathologies, **adduction** combined with external rotation is not the typical initial position for tubercular synovitis. - Adduction usually occurs in later, destructive stages due to muscle contractures or subluxation. *Flexion, abduction, internal rotation* - Although flexion and abduction are components of the correct answer, **internal rotation** is not typically observed in the early synovial stage of tubercular hip disease. - Internal rotation is more commonly associated with other hip conditions or specific muscle spasms not characteristic of early TB synovitis.

Q: Most common joint involved in septic arthritis:

Knee. ***Knee*** - The **knee joint** is the most commonly affected joint in **septic arthritis**, accounting for about 50% of cases in adults. - Its large size and frequent exposure to trauma contribute to its susceptibility to infection. *Hip* - The hip joint is the **second most common site** for septic arthritis in adults, especially in children and the elderly. - While significant, its incidence is lower than that of the knee. *Shoulder* - The shoulder can be affected by septic arthritis, particularly in individuals with **intravenous drug use** or those who are **immunocompromised**. - However, it is less frequently involved compared to the knee and hip. *Elbow* - Septic arthritis of the elbow is relatively **uncommon** compared to the larger weight-bearing joints. - It may be seen in cases of trauma or systemic infection, but it is not the most common site.

Q: During performing a total hip replacement, the surgeon found destruction of the articular cartilage and multiple wedge-shaped subchondral depressions. What is this called?

Osteonecrosis. ***Osteonecrosis*** - **Osteonecrosis**, also known as **avascular necrosis**, is characterized by the death of bone tissue due to a lack of blood supply, which leads to the collapse of the subchondral bone and articular cartilage destruction. - The description of **wedge-shaped subchondral depressions** and **articular cartilage destruction** is highly indicative of osteonecrosis, especially in the context of advanced hip joint pathology requiring total hip replacement. *Osteolysis* - **Osteolysis** refers to the active resorption of bone, often seen around implants in prosthetic joints due to wear particles, leading to bone loss. - While it involves bone destruction, it typically presents as diffuse bone loss rather than specific wedge-shaped subchondral depressions. *Osteomyelitis* - **Osteomyelitis** is an infection of the bone or bone marrow, often leading to bone destruction, but it is primarily characterized by inflammation and pus formation. - The presented scenario does not mention signs of infection (e.g., fever, pus, inflammation) but focuses purely on structural destruction consistent with vascular compromise. *Osteogenesis* - **Osteogenesis** is the process of bone formation or development. - This term describes the creation of bone tissue and is the opposite of bone destruction, making it an incorrect answer for a condition involving cartilage and bone deterioration.

Q: Bulge sign in the knee joint is seen after how much fluid accumulation?

< 30 ml. **< 30 ml** - The **bulge sign** is a sensitive test for detecting small amounts of **effusion** in the knee joint. - It is typically positive with as little as 4-8 mL to 10-30 mL of fluid, making "< 30 mL" the most appropriate answer. *100 ml* - An effusion of 100 mL is a **moderate to large amount** of fluid, which would typically elicit a positive **patellar tap test (ballottement)** rather than just a bulge sign. - The **bulge sign** is designed to detect much smaller effusions. *400 ml* - This represents a **very large effusion** that would be clinically obvious and cause significant swelling and discomfort, far exceeding the threshold for a simple bulge sign. - A knee with 400 mL of fluid would likely have a tense, bulging appearance and a very prominent **patellar tap**. *200 ml* - This is also a **significant effusion** that would easily be detected by a patellar tap test and would present with gross swelling. - The **bulge sign** is specifically for subtler fluid collections.

Q: What is another name for ischial bursitis?

Weaver's bottom. ***Weaver's bottom*** - This is a common **colloquial term** for ischial bursitis, describing the condition that can arise from prolonged sitting. - The **ischial bursa** lies between the ischial tuberosity and the gluteus maximus, which can become inflamed from pressure. *Prepatellar bursitis* - This refers to inflammation of the bursa located over the **kneecap**. - It is often called **"housemaid's knee"** due to its association with prolonged kneeling. *Trochanteric bursitis* - This is inflammation of the bursa located over the **greater trochanter of the femur**, on the outer side of the hip. - It causes pain in the **lateral hip region**, often radiating down the thigh. *Olecranon bursitis* - This involves inflammation of the bursa located at the **tip of the elbow** (olecranon process). - It is sometimes called **"student's elbow"** or **"miner's elbow"** due to repetitive trauma or pressure.

Q: How is Brodie's abscess classified?

Chronic osteomyelitis (Brodie's abscess). ***Chronic osteomyelitis (Brodie's abscess)*** - Brodie's abscess is a **subacute or chronic localized osteomyelitis**, characterized by an intraosseous abscess often surrounded by a thick layer of sclerotic bone. - It represents a **contained infection** within the bone, lacking the widespread inflammatory response seen in acute forms. *Acute osteomyelitis* - Characterized by a **rapid onset** of severe pain, fever, and inflammation, usually within days to weeks of infection. - It involves a **widespread inflammatory process** and potential for bone destruction, differentiated from the contained and indolent nature of Brodie's abscess. *Subacute osteomyelitis* - This term describes an osteomyelitis with a more gradual onset and less severe symptoms than acute osteomyelitis, typically lasting several weeks to a few months. - While Brodie's abscess can present subacutely, it is specifically classified as a **form of chronic osteomyelitis** due to its localized, walled-off nature and prolonged course. *Septic arthritis* - Involves an infection within a **joint space**, leading to inflammation and destruction of articular cartilage. - It is distinct from Brodie's abscess, which is an infection of the **bone tissue itself**, not the joint.

Q: Which of the following is an orthopedic emergency?

Septic arthritis. ***Septic arthritis*** - This is an **orthopedic emergency** due to the rapid destruction of cartilage and bone if not treated promptly. - It requires urgent **surgical washout** and intravenous antibiotics to prevent irreversible joint damage and systemic infection. *Intraarticular fracture* - While requiring careful management to optimize joint function, an **intraarticular fracture** is typically not an immediate emergency unless there's associated neurovascular compromise or compartment syndrome. - Surgical intervention can often be planned within a certain timeframe (days) rather than hours. *Fracture lateral condyle humerus* - This fracture in children is significant due to potential for non-union or avascular necrosis, but it is not considered an immediate **life- or limb-threatening emergency**. - Management usually involves **reduction and fixation** but does not carry the same degree of urgency as active joint infection. *Fracture neck femur* - A fractured neck of femur requires surgical intervention to prevent complications like **avascular necrosis** and optimize mobility, particularly in elderly patients. - While serious, it primarily presents a risk of long-term disability and complications, not an immediate destructive process like septic arthritis.

Question 1

X-ray appearance of sequestrum?

Accepted Answer

Radiodense bone fragments

Answer

Osteopenic fragment

Answer

Fragment with honeycomb loculated appearance

Answer

Radiolucent area with speckled calcification

Question 2

First radiological sign for active tubercular arthritis is?

Accepted Answer

Localized osteoporosis

Answer

Sclerosis

Answer

Joint space reduction

Answer

Osteophytes

Question 3

A 20 year old male presents with history of gradual onset pain and swelling in left knee since 6 months. Now since last 1 month patient has started limping while walking and also has flexion deformity of knee. Ultrasonography shows presence of synovial thickening. What is the most probable diagnosis?

Accepted Answer

Tuberculosis of the knee

Answer

Synovial sarcoma

Answer

Hemarthrosis

Answer

Pigmented villonodular synovitis

Question 4

Deformity of hip in stage of tubercular synovitis?

Accepted Answer

Flexion, abduction external rotation

Answer

Flexion, adduction internal rotation

Answer

Flexion, abduction, internal rotation

Answer

Flexion, adduction, external rotation

Question 5

Most common joint involved in septic arthritis:

Accepted Answer

Knee

Answer

Hip

Answer

Shoulder

Answer

Elbow

Question 6

During performing a total hip replacement, the surgeon found destruction of the articular cartilage and multiple wedge-shaped subchondral depressions. What is this called?

Accepted Answer

Osteonecrosis

Answer

Osteolysis

Answer

Osteomyelitis

Answer

Osteogenesis

Question 7

Bulge sign in the knee joint is seen after how much fluid accumulation?

Accepted Answer

< 30 ml

Answer

200 ml

Answer

100 ml

Answer

400 ml

Question 8

What is another name for ischial bursitis?

Accepted Answer

Weaver's bottom

Answer

Trochanteric bursitis

Answer

Prepatellar bursitis

Answer

Olecranon bursitis

Question 9

How is Brodie's abscess classified?

Accepted Answer

Chronic osteomyelitis (Brodie's abscess)

Answer

Acute osteomyelitis

Answer

Subacute osteomyelitis

Answer

Septic arthritis

Question 10

Which of the following is an orthopedic emergency?

Accepted Answer

Septic arthritis

Answer

Intraarticular fracture

Answer

Fracture lateral condyle humerus

Answer

Fracture neck femur

Arthrology and Infections — MCQs

Arthrology and Infections — MCQs

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