Arthrology and Infections Practice Questions

Q: A patient presents with a ring-shaped (lytic) lesion in the bone. Which of the following is the most likely diagnosis?

Brodie's abscess. ***Brodie's abscess*** - This is a localized form of **subacute osteomyelitis** that presents as a well-circumscribed, **lytic lesion** with a thick, **sclerotic rim**, creating a classic ring-shaped appearance. - It is most commonly found in the **metaphysis** of long bones, particularly the **tibia**, and represents a contained infection where the body has walled off the pathogen. *Aneurysmal bone cyst* - Characterized as an **expansile**, multiloculated lytic lesion often described as having a **"soap bubble"** appearance rather than a simple ring. - It is a highly **vascular** lesion that typically causes significant **cortical thinning** and eccentricity, rather than a dense sclerotic reactive rim. *Simple bone cyst* - Appears as a central, well-demarcated lytic lesion that typically causes **cortical expansion** and thinning but lacks the distinct **sclerotic margin** found in Brodie's abscess. - It is classically associated with the **"fallen fragment" sign** following a pathological fracture, which is diagnostic for this fluid-filled cavity. *Osteoid osteoma* - Presents as a small radiolucent **nidus** (usually <1.5 cm) surrounded by a very large, disproportionate area of **reactive sclerosis**. - The clinical hallmark is severe **nocturnal pain** that is dramatically relieved by **salicylates** (aspirin) or other NSAIDs.

Q: A 42-year-old woman laborer presented with visible, soft, and fluctuating swelling in front of the knee, over the patella and some discomfort or difficulty with knee movement, MRI findings are given below. What is the diagnosis?

Housemaid's knee. ***Housemaid's knee*** - This condition, also known as **prepatellar bursitis**, involves inflammation and fluid accumulation in the bursa located directly in front of the patella, matching the MRI findings and the patient's clinical presentation. - It is frequently associated with occupations that require prolonged kneeling, such as being a laborer, leading to chronic irritation and swelling in this specific location. *Subdermal abscess* - A subdermal abscess would typically present with more pronounced signs of infection, such as significant warmth, **erythema** (redness), and systemic symptoms like fever, which are not mentioned in this case. - On MRI, an abscess often shows a more complex fluid collection with **rim enhancement** after contrast administration, distinguishing it from the simple bursal fluid seen here. *Gout* - Gout is an **intra-articular** arthritis caused by **urate crystal** deposition, which would cause swelling within the knee joint itself, not a localized collection in front of the patella. - The classic presentation is an acute, intensely painful, and red joint, most commonly the first **metatarsophalangeal joint** (podagra), which differs from this patient's presentation. *Rheumatoid arthritis* - Rheumatoid arthritis is a systemic inflammatory condition that typically causes **symmetric polyarthritis** of small joints in the hands and feet. - While it can affect the knee, it causes an **intra-articular** effusion (swelling within the joint space) and synovitis, not isolated prepatellar bursitis.

Q: A 15-day-old neonate was brought with complaints of high grade fever for 2 days and decreased playing movements of right leg. On examination the right knee joint is red, tender and shows fluctuation. All are true about the condition shown except:

Intravenous treatment given till CRP levels normalize. **Intravenous treatment given till CRP levels normalize** - Treatment for **septic arthritis** in neonates typically involves intravenous antibiotics. However, the duration of treatment is usually guided by clinical improvement and normalization of **ESR and CRP levels**, not just CRP. - While CRP normalization is a good indicator of falling inflammation, maintaining IV antibiotics until **ESR also normalizes** is often recommended to ensure complete eradication and prevent recurrence. *Most common cause is Staph. aureus* - **Staphylococcus aureus** is indeed the **most common cause** of septic arthritis in neonates. - The clinical presentation of **fever**, **decreased limb movement**, and a **red, tender, fluctuating joint** is highly suggestive of septic arthritis. *Golden yellow pigment produced by organism* - **Staphylococcus aureus** gets its name from its golden (aureus) pigment, **staphyloxanthin**, which gives colonies a golden-yellow hue. - This pigment also functions as a **virulence factor**, primarily as an antioxidant, helping the bacteria resist immune defenses. *Urgent arthrotomy to debride infected synovium* - **Urgent arthrotomy** (surgical drainage and debridement) is indicated in **septic arthritis** to remove pus, reduce intra-articular pressure, and prevent cartilage damage. - This procedure is crucial in preventing **long-term complications** such as joint destruction and growth disturbances in infants, especially in joints like the hip and knee.

Q: All the following statements regarding this image are true except: (Recent NEET Pattern 2016-17)

This is a soft tissue tumor. ***This is a soft tissue tumor*** - The image shows a swelling over the olecranon process, which is characteristic of **olecranon bursitis**. This condition is an **inflammation of the bursa**, not a soft tissue tumor. - A tumor implies an abnormal growth of tissue that can be benign or malignant, which is not depicted here; the swelling is related to fluid accumulation within a bursa. *This condition could result from student's elbow* - **Student's elbow** is another name for olecranon bursitis, which is the condition depicted in the image. - This common term refers to the inflammation of the olecranon bursa, often caused by **repetitive pressure or trauma** to the elbow, such as leaning on it for extended periods while studying. *It is secondary to trauma* - **Trauma**, especially repetitive minor trauma or a single significant impact, is a very common cause of olecranon bursitis due to injury to the bursa. - This trauma can lead to inflammation and fluid accumulation within the bursa, causing the characteristic swelling. *This condition is due to inflammation of the sub-cutaneous fat* - The condition shown is **olecranon bursitis**, which is an inflammation of the **olecranon bursa**. - The olecranon bursa is a fluid-filled sac that lies between the skin and the olecranon process of the ulna to reduce friction, and its inflammation is distinct from inflammation of the subcutaneous fat (panniculitis).

Q: Which complication of osteomyelitis is shown below?

Brodie's abscess. ***Brodie's abscess*** - The image suggests a well-circumscribed, **radiolucent lesion** with a sclerotic rim within the bone, which is characteristic of a Brodie's abscess. - This is a subacute or chronic form of osteomyelitis, often appearing as a **focal lucency** in the metaphysis of long bones. *Garre's osteomyelitis* - This is characterized by **diffuse periosteal new bone formation** and cortical thickening, giving a "onion peel" appearance, which is not seen in the image. - It typically results from a low-grade infection and leads to **sclerosis and hypertrophy** of the bone. *Bony ankyloses* - **Bony ankylosis** refers to the fusion of two bones across a joint, resulting in immobility. - This image shows a lesion within a single bone, not a **fused joint**. *All of the above* - This option is incorrect because the image specifically depicts features of a Brodie's abscess, ruling out Garre's osteomyelitis and bony ankylosis. - Therefore, not all the conditions listed are represented in the provided image.

Q: A 10-year-old child presents with fever and wound with discharging pus from right thigh for 4 months. Given below is the X -ray of the patient. Identify the marked area:

Sequestrum. ***Sequestrum*** - The arrow points to a dense, isolated fragment of **necrotic bone** within the bone shaft, which is a classic radiographic finding of a **sequestrum** in chronic osteomyelitis. - In chronic osteomyelitis, the host immune system attempts to wall off the infection, leading to bone necrosis and the formation of this devitalized bone fragment. *Cloacae* - A cloaca is an opening or channel in the **involucrum** (new bone formation) through which pus and necrotic debris (sequestrum) can drain from the infected bone. - The image does not clearly show an opening for drainage; rather, it highlights an internal bone fragment. *Involucrum* - The involucrum is a sheath of **new bone formation** that encapsulates the infected, necrotic bone (sequestrum) in chronic osteomyelitis. - While new bone formation is likely present, the arrow specifically indicates the denser, dead bone fragment rather than the surrounding reactive new bone. *Woven bone* - **Woven bone** is immature, rapidly formed bone, often seen during bone development, fracture healing, or in certain pathological conditions like fibrous dysplasia or Paget's disease. - The marked area is a distinct fragment of necrotic cortical bone, not indicative of diffuse woven bone formation.

Q: A 52-year-old female complains of increasing pain in the right shoulder. She is also finding it increasingly difficult to do overhead abduction of the affected joint. She had been diagnosed as a diabetic 20 years back and is on treatment since then. What is the most likely cause of her clinical condition?

Frozen shoulder. ***Frozen shoulder*** - The patient's presentation with **increasing pain** and **difficulty with overhead abduction** of the shoulder, especially in the context of long-standing **diabetes**, is highly characteristic of **adhesive capsulitis** (frozen shoulder). - This condition is marked by **progressive stiffness** and **restricted range of motion** in the shoulder joint due to inflammation and fibrosis of the joint capsule. *Bacterial arthritis* - **Bacterial arthritis** typically presents with an **acutely painful**, **swollen**, and **erythematous joint**, often accompanied by systemic symptoms like **fever** and **malaise**. - The chronic, progressive nature of the patient's symptoms and the absence of acute inflammatory signs or fever make bacterial arthritis less likely. *Osteoarthritis* - While **osteoarthritis** can cause shoulder pain and stiffness, it usually presents with **pain that worsens with activity** and is relieved by rest, often with **crepitus** and a more gradual loss of range of motion. - The pronounced restriction in **overhead abduction** in this patient, particularly given the diabetic history, points away from primary osteoarthritis as the most likely cause. *Rotator cuff tear* - A **rotator cuff tear** typically presents with pain and weakness, especially during **abduction** or **external rotation**, and may have a specific mechanism of injury. - While abduction can be difficult, the classic presentation of a frozen shoulder with severe, global restriction of both active and passive range of motion is a stronger fit for the described symptoms.

Q: With reference to frozen shoulder, consider the following statements: 1. It is associated with diabetes and heart disease. 2. It may follow minor trauma. 3. Its differential diagnosis are infection and fractures. 4. Treatment of choice is surgery. Which of the statements given above are correct?

1, 2 and 3. ***1, 2 and 3*** - **Frozen shoulder** (adhesive capsulitis) has a higher incidence in individuals with **diabetes mellitus** and **cardiovascular diseases**, indicating systemic associations. - It can be triggered by minor trauma or surgery, but often it has **no identifiable cause** (idiopathic). - The differential diagnoses for shoulder pain and restricted motion include serious conditions like **infection (septic arthritis)** and **fractures**, which must be ruled out. *1 and 2 only* - This option correctly identifies the association with diabetes and heart disease, and the possibility of minor trauma. - However, it incorrectly excludes the importance of considering infection and fractures in the differential diagnosis. *3 and 4 only* - This option correctly identifies the importance of differential diagnosis (infection and fractures). - However, **surgery is generally not the first-line treatment for frozen shoulder**; it is reserved for severe cases unresponsive to conservative measures. - It also fails to acknowledge the associations with diabetes and heart disease, or the role of minor trauma. *2, 3 and 4* - This option correctly notes that frozen shoulder can follow minor trauma and that infection and fractures are important differential diagnoses. - However, it incorrectly states that **surgery is the treatment of choice**, when **conservative management is usually first-line**. - It also misses the crucial association with **diabetes and heart disease**.

Question 1

A patient presents with a ring-shaped (lytic) lesion in the bone. Which of the following is the most likely diagnosis?

Accepted Answer

Brodie's abscess

Answer

Aneurysmal bone cyst

Answer

Simple bone cyst

Answer

Osteoid osteoma

Question 2

A 42-year-old woman laborer presented with visible, soft, and fluctuating swelling in front of the knee, over the patella and some discomfort or difficulty with knee movement, MRI findings are given below. What is the diagnosis?

Accepted Answer

Housemaid's knee

Answer

Rheumatoid arthritis

Answer

Gout

Answer

Subdermal abscess

Question 3

A 15-day-old neonate was brought with complaints of high grade fever for 2 days and decreased playing movements of right leg. On examination the right knee joint is red, tender and shows fluctuation. All are true about the condition shown except:

Accepted Answer

Intravenous treatment given till CRP levels normalize

Answer

Most common cause is Staph. aureus

Answer

Golden yellow pigment produced by organism

Answer

Urgent arthrotomy to debride infected synovium

Question 4

All the following statements regarding this image are true except: (Recent NEET Pattern 2016-17)

Accepted Answer

This is a soft tissue tumor

Answer

This condition could result from student's elbow

Answer

It is secondary to trauma

Answer

This condition is due to inflammation of the sub-cutaneous fat

Question 5

All are correct about the X-ray film shown below except:

Accepted Answer

Antibiotic weight should be less than 10 % of bone cement weight

Answer

Antibiotic bead implantation

Answer

Preferred antibiotic impregnated in the beads is aminoglycosides

Answer

PMMA beads used prophylactically to limit SSI

Question 6

Which complication of osteomyelitis is shown below?

Accepted Answer

Brodie's abscess

Answer

Garre's osteomyelitis

Answer

Bony ankyloses

Answer

All of the above

Question 7

In the given image of chronic osteomyelitis choose the correct sequence:

Accepted Answer

A-infected, C- Dead bone, E- Reactive bone, D- Draining sinus

Answer

A- Normal, C- Sequestrum, E- Involucrum, D- Cloacae

Answer

A- Normal, C- Involucrum, E- Sequestrum, D- Draining sinus

Answer

A-infected, C- Reactive bone, E- Dead bone, D- Draining sinus

Question 8

A 10-year-old child presents with fever and wound with discharging pus from right thigh for 4 months. Given below is the X -ray of the patient. Identify the marked area:

Accepted Answer

Sequestrum

Answer

Cloacae

Answer

Involucrum

Answer

Woven bone

Question 9

A 52-year-old female complains of increasing pain in the right shoulder. She is also finding it increasingly difficult to do overhead abduction of the affected joint. She had been diagnosed as a diabetic 20 years back and is on treatment since then. What is the most likely cause of her clinical condition?

Accepted Answer

Frozen shoulder

Answer

Bacterial arthritis

Answer

Osteoarthritis

Answer

Rotator cuff tear

Question 10

With reference to frozen shoulder, consider the following statements:

1. It is associated with diabetes and heart disease.

2. It may follow minor trauma.

3. Its differential diagnosis are infection and fractures.

4. Treatment of choice is surgery.
Which of the statements given above are correct?

Accepted Answer

1, 2 and 3

Answer

1 and 2 only

Answer

3 and 4 only

Answer

2, 3 and 4

Arthrology and Infections — MCQs

Arthrology and Infections — MCQs

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