Arthrology and Infections Practice Questions

Q: Syndesmophytes are seen in which of the following conditions?

Ankylosing Spondylitis. **Explanation:** **Syndesmophytes** are the hallmark radiological feature of **Ankylosing Spondylitis (AS)**. They represent vertical bony outgrowths that develop due to inflammation and subsequent ossification of the outer fibers of the **annulus fibrosus** of the intervertebral discs. * **Why Option A is correct:** In AS, chronic enthesitis (inflammation at the site where ligaments/tendons attach to bone) leads to the formation of these thin, vertical, and symmetrical bony bridges between adjacent vertebrae. When these bridges connect multiple levels, it creates the classic **"Bamboo Spine"** appearance on X-ray. * **Why Option B is incorrect:** Rheumatoid Arthritis (RA) primarily affects the synovial joints (like the atlantoaxial joint in the spine) and causes bone **erosions** and joint space narrowing, not new bone formation like syndesmophytes. * **Why Option C is incorrect:** Osteoarthritis (OA) of the spine (Spondylosis) produces **Osteophytes**. Unlike syndesmophytes, osteophytes are horizontal, thick, and claw-like protrusions that arise from the vertebral body margins due to mechanical stress, rather than vertical ossification of the ligaments. **High-Yield Clinical Pearls for NEET-PG:** * **HLA-B27:** Strongly associated with Ankylosing Spondylitis (>90% of cases). * **Sacroiliitis:** The earliest radiological sign of AS (usually bilateral and symmetrical). * **Dagger Sign:** A single central radiodense line on X-ray due to ossification of the supraspinous and interspinous ligaments. * **Schober’s Test:** Used clinically to assess the restriction of lumbar spine flexion. * **Marginal vs. Non-marginal:** AS has *marginal* syndesmophytes, while Psoriatic Arthritis and Reiter’s syndrome have *non-marginal* (bulky/asymmetric) syndesmophytes.

Q: Which of the following is NOT a feature of Rheumatoid arthritis?

Osteosclerosis of the joint. **Explanation:** Rheumatoid Arthritis (RA) is a chronic, systemic inflammatory disease primarily affecting the **synovium**. The hallmark of RA is inflammatory pannus formation, which leads to bone destruction rather than bone formation. **Why Osteosclerosis is NOT a feature:** **Osteosclerosis** (increased bone density/hardening) is a characteristic feature of **Osteoarthritis (OA)**, a degenerative joint disease. In OA, the loss of cartilage leads to increased mechanical stress on the subchondral bone, resulting in sclerosis and osteophyte formation. In contrast, the inflammatory cytokines (like TNF-α and IL-1) in RA activate osteoclasts, leading to bone loss (osteopenia/erosion) rather than hardening. **Analysis of other options:** * **Soft tissue swelling:** This is the earliest radiographic sign of RA, caused by synovial hypertrophy and joint effusion. * **Narrowing of the joint space:** As the inflammatory pannus destroys the articular cartilage, the space between the bone ends decreases symmetrically. * **Periarticular osteoporosis:** This is a classic early sign of RA. Localized inflammation increases blood flow (hyperemia) to the joint, which promotes demineralization of the bone immediately surrounding the inflamed synovium. **NEET-PG High-Yield Pearls:** * **Radiological Hallmarks of RA:** Symmetric joint space narrowing, periarticular osteopenia, marginal erosions (at the "bare area"), and joint deformities (e.g., Swan-neck, Boutonniere). * **Radiological Hallmarks of OA:** Asymmetric joint space narrowing, **subchondral sclerosis**, subchondral cysts (Geodes), and osteophytes. * **Key Distinction:** RA is an **erosive** disease; OA is a **productive** (bone-forming) disease.

Q: What is the commonest cause of acute osteomyelitis?

Hematogenous route. **Explanation:** **Hematogenous route (Option D)** is the most common cause of acute osteomyelitis, particularly in the pediatric population. This occurs when bacteria (most commonly *Staphylococcus aureus*) enter the bloodstream from a distant site (like a skin boil or sore throat) and settle in the **metaphysis** of long bones. The metaphysis is the preferred site due to its high vascularity and the presence of "hairpin loops" in the capillary bed, which lead to sluggish blood flow, allowing bacteria to settle and proliferate. **Analysis of Incorrect Options:** * **Trauma (Option A):** While open fractures or deep soft tissue injuries can lead to "Direct Inoculation Osteomyelitis," it is statistically less common than the hematogenous spread in the general population. * **Surgery (Option B):** Post-operative infections (e.g., after ORIF or joint replacement) are significant causes of *chronic* or *iatrogenic* osteomyelitis but do not represent the primary etiology of acute cases globally. * **Fungal infection (Option C):** Fungal osteomyelitis is rare and typically seen only in immunocompromised patients or those on long-term parenteral nutrition. **High-Yield Clinical Pearls for NEET-PG:** * **Most common organism:** *Staphylococcus aureus* (overall). * **Most common organism in Sickle Cell Anemia:** *Salmonella* (though *S. aureus* remains a close second). * **Most common site:** Metaphysis of long bones (Distal Femur > Proximal Tibia). * **Earliest X-ray sign:** Soft tissue swelling (seen at 3–5 days). Bony changes (periosteal reaction/rarefaction) take **10–14 days** to appear. * **Investigation of choice:** **MRI** (most sensitive for early diagnosis).

Q: Which of the following is NOT a differentiating feature between psoriatic arthritis and rheumatoid arthritis?

Mael's sign. **Explanation:** The question asks for the feature that does **not** differentiate Psoriatic Arthritis (PsA) from Rheumatoid Arthritis (RA). **Mael’s Sign** (also known as the "Mael sign" or "Mael's line") is actually a clinical sign associated with **scabies** (a linear burrow), not arthritic conditions. Therefore, it is the correct answer as it is irrelevant to the differentiation of these two types of arthritis. **Analysis of Incorrect Options (Differentiating Features):** * **Pencil-in-cup deformity:** This is a classic radiographic hallmark of **PsA**. It occurs due to periarticular erosions and resorption of the distal end of a phalanx (pencil) fitting into the expanded base of the adjacent phalanx (cup). It is not seen in RA. * **Telescoping of phalanges:** This occurs in **Arthritis Mutilans**, a severe form of PsA. Extensive osteolysis causes the bones to shorten, and the skin folds over the joint like a telescope (Opera-glass hand). While RA can cause joint destruction, this specific "telescoping" is characteristic of PsA. * **Tufting of phalanges:** Also known as acro-osteolysis, this refers to the resorption of the terminal phalangeal tufts. It is a feature of **PsA** (and scleroderma) but is absent in RA. **NEET-PG High-Yield Pearls:** 1. **Symmetry:** RA is typically symmetrical; PsA is often asymmetrical and involves the **DIP joints** (RA characteristically spares the DIP). 2. **Dactylitis:** "Sausage digits" are a hallmark of PsA, not RA. 3. **Serology:** RA is usually RF positive; PsA is a **Seronegative Spondyloarthropathy**. 4. **Radiology:** PsA shows a combination of bone destruction and **new bone formation** (periostitis), whereas RA is primarily a destructive process with periarticular osteopenia.

Q: Syndesmosis is a type of?

Fibrous. **Explanation:** Joints are classified based on the type of connective tissue that binds the bones together. **Syndesmosis** is a subtype of **Fibrous joints**, where two adjacent bones are linked by a strong interosseous membrane or ligament. Unlike sutures (which have minimal connective tissue), syndesmoses allow for slight, functional movement (amphiarthrosis). **Why the other options are incorrect:** * **Plain (Plane):** These are a subtype of **Synovial joints** characterized by flat articular surfaces that allow gliding movements (e.g., Intercarpal joints). * **Pivot:** This is a **Synovial joint** where a bony projection articulates within a ring formed by another bone and a ligament, allowing rotation (e.g., Atlanto-axial joint). * **Cartilaginous:** These joints are joined by hyaline or fibrocartilage. They are divided into Primary (Synchondrosis, e.g., Epiphyseal plate) and Secondary (Symphysis, e.g., Pubic symphysis). **High-Yield Clinical Pearls for NEET-PG:** 1. **Classic Examples:** The **Inferior Tibiofibular joint** and the **Middle Radio-ulnar joint** (interosseous membrane) are the most frequently tested examples of syndesmosis. 2. **Clinical Relevance:** A "High Ankle Sprain" refers to an injury of the inferior tibiofibular syndesmosis. 3. **Gomphosis:** Another specific type of fibrous joint is the Gomphosis (peg-and-socket), seen in the attachment of teeth to alveolar sockets. 4. **Sutures:** These are fibrous joints unique to the skull. In adults, when they ossify, they are termed **Synostoses**.

Q: Which of the following is true about acute osteomyelitis?

Severe pain.. **Explanation:** Acute Hematogenous Osteomyelitis (AHO) is a surgical emergency primarily seen in children. The correct answer is **Severe pain** because it is the most consistent and earliest clinical feature. 1. **Why "Severe Pain" is correct:** The infection typically starts in the **metaphysis** of long bones. As pus accumulates within the rigid medullary cavity, the intraosseous pressure rises significantly. This pressure stretches the sensitive periosteum, leading to excruciating, throbbing pain and exquisite point tenderness. This is often the "earliest" sign before systemic symptoms or radiological changes appear. 2. **Why other options are incorrect:** * **Option A:** While it is a classic teaching that X-rays are negative for 10–14 days, modern digital radiography can sometimes detect subtle soft tissue swelling or periosteal reactions slightly earlier (around 7–10 days). However, "cannot be detected" is an absolute statement that is less clinically definitive than the presence of pain. * **Option C:** While there is "pseudoparalysis" (the patient refuses to move the limb due to pain), the **joint movements** themselves are usually preserved if the joint is moved passively and gently. This helps differentiate it from Septic Arthritis, where any movement is impossible. * **Option D:** Bone scans (Technetium-99m) are highly sensitive and can detect increased uptake within **24 to 48 hours** of infection. Waiting 2 weeks would lead to irreversible bone necrosis (sequestrum). **NEET-PG High-Yield Pearls:** * **Most common site:** Metaphysis (due to hairpin bends of vessels and sluggish blood flow). * **Most common organism:** *Staphylococcus aureus*. * **Investigation of choice:** **MRI** (most sensitive and specific for early diagnosis). * **Earliest X-ray sign:** Soft tissue swelling and blurring of fat planes. * **Earliest Bone sign on X-ray:** Periosteal reaction (takes 10–14 days).

Q: What is the most common site of tuberculosis of the spine?

Dorsolumbar region. **Explanation:** Tuberculosis of the spine (Pott’s disease) is the most common form of skeletal tuberculosis. The **Dorsolumbar region (T12–L1)** is the most frequently affected site. This is primarily because this region represents a transitional zone where the relatively rigid thoracic spine meets the highly mobile lumbar spine, making it subject to significant mechanical stress. Additionally, the rich vascular supply via the paravertebral venous plexus (Batson’s plexus) facilitates the hematogenous spread of *Mycobacterium tuberculosis* to this area. **Analysis of Options:** * **Dorsolumbar region (Correct):** Statistically the most common site (specifically T12 and L1). It is the junctional area most prone to weight-bearing stress and infection. * **Dorsal/Thoracic region:** The second most common site. While common in children, it is less frequent than the dorsolumbar junction in the general population. * **Lumbar region:** Frequently involved, but usually as an extension or secondary to dorsolumbar involvement. * **Lumbosacral region:** A relatively rare site for primary spinal TB compared to the segments above it. **Clinical Pearls for NEET-PG:** * **Initial Site of Infection:** Usually the **paradiscal** region (anterior part of the vertebral body near the disc). * **Earliest Sign on X-ray:** Reduction/narrowing of the **intervertebral disc space**. * **Cold Abscess:** A hallmark of spinal TB; in the lumbar region, it often tracks down the psoas muscle sheath (Psoas abscess). * **Deformity:** The destruction of the anterior vertebral body leads to wedge collapse, resulting in **Kyphosis** (Gibbus deformity). * **Neurological Deficit:** Pott’s paraplegia is most common when the **upper dorsal spine** is involved due to the narrow canal diameter in that region.

Q: Chondrocalcinosis is seen with which of the following conditions?

Pseudogout. **Explanation:** **Pseudogout (Calcium Pyrophosphate Deposition Disease - CPPD)** is the correct answer because chondrocalcinosis is its hallmark radiographic feature. This condition involves the deposition of **calcium pyrophosphate dihydrate crystals** within articular cartilage and fibrocartilage. On X-ray, this appears as linear or punctate radiopacities within the joint space (most commonly the knee, wrist, and symphysis pubis). **Analysis of Options:** * **Gout:** Characterized by the deposition of **monosodium urate crystals**. Radiographically, it presents with "punched-out" erosions and "overhanging edges" (Martel’s sign), but not typically chondrocalcinosis. * **Osteoarthritis (OA):** While OA and CPPD often coexist in elderly patients, OA itself is characterized by joint space narrowing, subchondral sclerosis, and osteophyte formation, rather than cartilage calcification. * **Septic Arthritis:** This is an acute bacterial infection of the joint. Radiographs usually show soft tissue swelling in early stages and joint destruction in late stages, but not chondrocalcinosis. **High-Yield Clinical Pearls for NEET-PG:** * **Crystal Morphology:** Pseudogout crystals are **rhomboid-shaped** and show **weak positive birefringence** under polarized microscopy (Gout crystals are needle-shaped and strongly negative birefringent). * **Associated Conditions:** Always screen a patient with chondrocalcinosis for "The 3 H's": **Hyperparathyroidism, Hemochromatosis, and Hypomagnesemia**, as well as Hypothyroidism and Wilson's disease. * **Common Site:** The **knee joint** is the most common site for both clinical pseudogout and radiographic chondrocalcinosis.

Q: In which of the following conditions dactylitis cannot be seen?

Beta thalassemia. **Explanation:** **Dactylitis**, commonly known as "sausage digit," is the uniform swelling of a finger or toe resulting from inflammation of the small bones, tendons, and surrounding soft tissues. **Why Beta Thalassemia is the correct answer:** In **Beta Thalassemia**, the primary pathology is ineffective erythropoiesis and chronic hemolysis leading to expansion of the bone marrow. While this causes skeletal changes (like the "crew-cut" appearance on skull X-ray or "chipmunk facies"), it **does not** cause acute inflammation or infarction of the phalanges. Therefore, dactylitis is not a clinical feature of Beta Thalassemia. **Analysis of Incorrect Options:** * **Sickle Cell Anaemia:** This is the most common cause of dactylitis in infants (Hand-Foot Syndrome). It occurs due to **vaso-occlusive crises** leading to infarcts in the small bones of the hands and feet. * **Congenital Syphilis:** It causes **syphilitic dactylitis**, characterized by painless, symmetrical swelling of the proximal phalanges due to periostitis. * **Tuberculosis:** Known as **Spina Ventosa**, TB dactylitis involves a cold abscess and cystic expansion of the short tubular bones, usually seen in children. **NEET-PG High-Yield Pearls:** 1. **Spina Ventosa:** The classic radiological sign of TB dactylitis (subperiosteal new bone formation with internal bone destruction). 2. **Spondyloarthropathies:** Dactylitis is a hallmark feature of **Psoriatic Arthritis** (most common), Ankylosing Spondylitis, and Reactive Arthritis. 3. **Sarcoidosis:** Can also cause dactylitis, often presenting with a "lace-like" pattern on X-ray. 4. **Hand-Foot Syndrome:** In Sickle Cell, this is often the first clinical manifestation of the disease in early childhood.

Question 1

Syndesmophytes are seen in which of the following conditions?

Accepted Answer

Ankylosing Spondylitis

Answer

Rheumatoid Arthritis

Answer

Osteoarthritis

Answer

All of the above

Question 2

Which of the following is NOT a feature of Rheumatoid arthritis?

Accepted Answer

Osteosclerosis of the joint

Answer

Soft tissue swelling

Answer

Narrowing of the joint space

Answer

Periarticular osteoporosis

Question 3

What is the commonest cause of acute osteomyelitis?

Accepted Answer

Hematogenous route

Answer

Trauma

Answer

Surgery

Answer

Fungal infection

Question 4

Which of the following is NOT a differentiating feature between psoriatic arthritis and rheumatoid arthritis?

Accepted Answer

Mael's sign

Answer

Pencil-in-cup deformity

Answer

Telescoping of phalanges

Answer

Tufting of phalanges

Question 5

Which of the following is false regarding Charcot's joint in diabetes mellitus?

Accepted Answer

Total ankle replacement

Answer

Limitation of movements with bracing

Answer

Arthrodesis

Answer

Arthrocentesis

Question 6

Syndesmosis is a type of?

Accepted Answer

Fibrous

Answer

Plain

Answer

Pivot

Answer

Cartilaginous

Question 7

Which of the following is true about acute osteomyelitis?

Accepted Answer

Severe pain.

Answer

Cannot be detected by X-ray before 2 weeks.

Answer

Limitation of movements.

Answer

Bone scan detects after 2 weeks.

Question 8

What is the most common site of tuberculosis of the spine?

Accepted Answer

Dorsolumbar region

Answer

Dorsal region

Answer

Lumbar region

Answer

Lumbosacral region

Question 9

Chondrocalcinosis is seen with which of the following conditions?

Accepted Answer

Pseudogout

Answer

Gout

Answer

Osteoarthritis

Answer

Septic arthritis

Question 10

In which of the following conditions dactylitis cannot be seen?

Accepted Answer

Beta thalassemia

Answer

Sickle cell anaemia

Answer

Congenital syphilis

Answer

Tuberculosis

Arthrology and Infections — MCQs

Arthrology and Infections — MCQs

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