Arthrology and Infections Practice Questions

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 a common complication of joint tuberculosis?

Fibrous ankylosis. ***Fibrous ankylosis*** - Joint tuberculosis commonly leads to **fibrous ankylosis** due to chronic inflammation and destruction of articular cartilage, promoting the formation of fibrous tissue that limits joint movement. - This complication results from the body's attempt to heal the persistent inflammatory process, creating a stiff and immoveable joint. *Bony ankylosis* - While possible in severe, long-standing cases, **bony ankylosis** (fusion of bones) is less common in joint tuberculosis than fibrous ankylosis. - It typically occurs in diseases like **ankylosing spondylitis** or advanced rheumatoid arthritis, where new bone formation bridges joint spaces. *Normal healing* - **Normal healing** with full restoration of joint function is rare in untreated or late-diagnosed joint tuberculosis due to the destructive nature of the infection. - The disease often causes significant damage to cartilage and bone, precluding complete recovery without sequelae. *None of the options* - This option is incorrect because **fibrous ankylosis** is a well-recognized and frequent complication of joint tuberculosis. - The chronic inflammatory response and tissue destruction inherent to the disease make complications highly probable.

Q: After chronic use of steroids severe pain in right hip with immobility is due to

Avascular necrosis. ***Avascular necrosis*** - Chronic **steroid use** is a major risk factor for avascular necrosis (AVN), particularly affecting the **femoral head** of the hip. - Reduced blood supply leads to bone death, resulting in severe pain and impaired mobility. *Perthes disease* - This is a condition of idiopathic **avascular necrosis of the femoral head** occurring in **children**, primarily between ages 4-10. - It is not associated with steroid use and typically presents in a different age group. *Hip dislocation* - Hip dislocation presents with **acute, severe pain** and an inability to bear weight or move the hip, often due to significant trauma. - While it causes immobility, it is an **acute traumatic event** rather than a chronic consequence of steroid use. *Osteoarthritis* - Osteoarthritis is a degenerative joint disease characterized by **cartilage breakdown** and joint pain that typically **worsens with activity** and improves with rest. - While chronic hip pain can be due to osteoarthritis, its direct link to steroid use for severe pain and immobility as described is less prominent than AVN.

Q: What is the most reliable method for diagnosing septic arthritis?

Joint aspiration for synovial fluid analysis. Direct examination of the **synovial fluid** is crucial for identifying the causative organism and confirming septic arthritis [1]. Key diagnostic features from synovial fluid include **leukocyte count** (usually >50,000 cells/mm³ with >75% neutrophils), **Gram stain** for bacteria, and **culture** for definitive organism identification. Joint aspiration should be performed as part of emergency management, often using a large-bore needle [1]. *X-ray imaging to detect joint abnormalities* - X-rays may show **joint effusions** or **soft tissue swelling** in early septic arthritis, but these are nonspecific findings. - **Bony erosions** or **joint space narrowing** typically appear only in **later stages** of the disease and are not diagnostic early on [2]. *Ultrasound (USG) imaging to detect effusion* - Ultrasound is effective for detecting and guiding aspiration of **joint effusions**, which are common in septic arthritis. - However, it does not confirm the **presence of infection** or identify the **causative agent**, making it a supportive, not primary diagnostic, tool. *MRI for detailed joint imaging* - MRI offers detailed imaging of **soft tissues**, cartilage, and bone, and can show **synovial enhancement**, **bone marrow edema**, and early **cartilage destruction** in septic arthritis. - While sensitive, MRI is **expensive** and **time-consuming**, and ultimately does not provide **microbiological confirmation**, which is essential for definitive diagnosis and treatment.

Q: Cloacae are openings found in which of the following?

Involucrum. ***Involucrum*** - **Cloacae** are openings or sinuses that develop in the **involucrum**, which is the new bone formation that surrounds a segment of necrotic bone (sequestrum) during osteomyelitis. - These openings act as channels for the discharge of **pus** and inflammatory debris from the infected bone to the external environment. *Sequestrum* - A **sequestrum** is a piece of **necrotic (dead) bone** that has become separated from the surrounding healthy bone due to osteomyelitis. - While central to the pathology, the cloacae are openings *through the involucrum* that encases the sequestrum, not in the sequestrum itself. *Normal bone* - **Normal bone** does not contain cloacae; these structures are a pathological feature indicative of chronic osteomyelitis. - Healthy bone remodels and resorbs normally, without the formation of channels for pus drainage. *Myositis* - **Myositis** is an inflammation of the **muscles**, not bone, and does not involve the formation of cloacae. - While it can be caused by infection, the pathological changes are localized to muscle tissue.

Q: Apparent lengthening is seen in which stage of TB Hip

Stage III. ***Stage III*** - In **Stage III (destructive stage)** of TB Hip, significant destruction of the femoral head and acetabulum can lead to superior migration of the greater trochanter. - This superior migration results in **apparent lengthening** of the limb due to the loss of bone structure and joint space. *Stage I* - **Stage I (synovitic stage)** involves inflammation of the synovium with effusion, but no significant bone destruction or joint changes that would cause lengthening. - At this stage, the joint space is usually preserved, and **no appreciable limb length discrepancy** is observed. *Stage II* - **Stage II (cartilage and early bone destruction)** begins to show destruction of articular cartilage and subchondral bone. - While there is some destruction, it is generally not extensive enough to cause the characteristic **apparent lengthening** seen in later stages. *None of the options* - This option is incorrect because **apparent lengthening** is a well-recognized feature during the advanced destructive phase (Stage III) of TB Hip. - The progressive nature of the disease directly contributes to specific radiographic and clinical findings like **unstable hip** and subsequent lengthening or shortening.

Q: Sequestrum is best defined as

A piece of dead bone surrounded by infected tissue. ***A piece of dead bone surrounded by infected tissue*** * A sequestrum is a fragment of **necrotic (dead) bone** that has become separated from the surrounding living bone in the context of **chronic osteomyelitis**. * The dead bone is typically surrounded by **infected granulation tissue and pus**, making it the classic definition taught in the context of bone infections. * The sequestrum acts as a **nidus for persistent infection**, as antibiotics cannot penetrate the avascular dead bone, making surgical removal often necessary. *A piece of dead bone without surrounding infection* * While a sequestrum is fundamentally dead bone, in clinical practice and standard teaching, it is **intrinsically associated with infection** in osteomyelitis. * The phrase "without surrounding infection" makes this option incorrect, as the classic sequestrum occurs in the **inflammatory milieu of chronic osteomyelitis**. *A piece of bone with compromised blood supply* * This describes **ischemic or avascular bone**, which is the **initial pathological event** that leads to bone death. * However, this is not the definition of sequestrum itself—the sequestrum is the **end result** (dead bone fragment) rather than bone with compromised vascularity. * A sequestrum has **no blood supply** (completely avascular), not merely compromised supply. *None of the options* * This is incorrect because the first option accurately captures the **standard definition of sequestrum** as taught in the context of chronic osteomyelitis in medical education.

Q: Which of the following statements about Pott's spine is false?

Always heals by chemotherapy. ***Always heals by chemotherapy*** - This statement is false because while **chemotherapy** (anti-tubercular drugs) is the primary treatment for **Pott's disease** (tuberculosis of the spine), healing is not always guaranteed and can sometimes require **surgical intervention** in cases of severe neurological deficit or instability. - The success of treatment depends on early diagnosis, patient compliance, and the severity of the disease, and not all cases resolve completely without residual issues. *Commonest at dorsolumbar junction* - **Pott's spine**, or **vertebral tuberculosis**, most frequently affects the **thoracic** and **lumbar regions**, particularly the **dorsolumbar junction** (T9-L1). - This predilection is attributed to the rich vascular supply and increased mechanical stress in this area. *Back pain is an early symptom* - **Back pain** is often one of the **earliest and most common symptoms** of Pott's spine, due to inflammation and destruction of vertebral bodies. - The pain is typically **localized**, progressive, and may worsen with movement. *There is disc space narrowing on x-ray* - **X-rays** of Pott's spine often show **disc space narrowing** along with vertebral destruction and collapse, differentiating it from pyogenic osteomyelitis where disc spaces might be initially preserved. - This narrowing is a consequence of the tuberculous infection spreading from the vertebral body to the adjacent **intervertebral disc**.

Q: Which of the following conditions can cause locking of the knee joint?

Loose body in knee joint. ***Loose body in knee joint*** - A **loose body** (e.g., a fragment of cartilage or bone) can get trapped between the articular surfaces of the knee joint, mechanically obstructing its movement and causing sudden, painful **locking**. - This mechanical impingement prevents full extension or flexion of the knee until the loose body shifts, leading to episodic locking symptoms. *Osgood Schlatter* - This condition involves inflammation and potential avulsion of the **tibial tuberosity** where the patellar tendon inserts. - It primarily causes pain and swelling below the kneecap, especially during physical activity, but does not typically result in true mechanical locking of the joint. *Tuberculosis of knee* - **Tuberculosis of the knee joint** is an infectious arthritis that causes chronic pain, swelling, and gradual destruction of articular cartilage and bone. - While it can lead to pain and limited range of motion, it usually does not present with the sudden, intermittent mechanical locking characteristic of a loose body. *a and b both* - Neither **Osgood Schlatter** nor **Tuberculosis of the knee** typically cause the characteristic mechanical locking sensation described for a loose body in the joint. - Each of these conditions has distinct pathophysiological mechanisms and clinical presentations that do not involve a physical obstruction causing locking.

Q: Triple deformity of the knee includes all except:

Medial rotation of tibia. ***Medial rotation of tibia*** - The "triple deformity of the knee" in **posterior cruciate ligament (PCL) injury** refers to a combination of three specific physical findings: **posterior subluxation of the tibia**, **lateral rotation of the tibia**, and **flexion of the knee**. - **Medial rotation** is not typically part of this specific pathological triad. *Posterior subluxation of tibia* - This is a key component of the triple deformity, indicating the tibia has shifted **posteriorly** relative to the femur. - It arises from the loss of the PCL's primary restraint against posterior tibial translation. *Lateral rotation of tibia* - This is another characteristic component, where the tibia exhibits **excessive external rotation** relative to the femur. - This often contributes to the overall instability and compensatory mechanisms seen in PCL deficiency. *Flexion* - The knee often assumes a position of **flexion** at rest or during gait in patients with a triple deformity. - This can be due to compensatory mechanisms or the inability to fully extend the knee given the other deformities.

Question 1

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 2

What is a common complication of joint tuberculosis?

Accepted Answer

Fibrous ankylosis

Answer

Bony ankylosis

Answer

Normal healing

Answer

None of the options

Question 3

After chronic use of steroids severe pain in right hip with immobility is due to

Accepted Answer

Avascular necrosis

Answer

Perthes disease

Answer

Hip dislocation

Answer

Osteoarthritis

Question 4

What is the most reliable method for diagnosing septic arthritis?

Accepted Answer

Joint aspiration for synovial fluid analysis

Answer

X-ray imaging to detect joint abnormalities

Answer

Ultrasound (USG) imaging to detect effusion

Answer

MRI for detailed joint imaging

Question 5

Cloacae are openings found in which of the following?

Accepted Answer

Involucrum

Answer

Sequestrum

Answer

Normal bone

Answer

Myositis

Question 6

Apparent lengthening is seen in which stage of TB Hip

Accepted Answer

Stage III

Answer

Stage II

Answer

Stage I

Answer

None of the options

Question 7

Sequestrum is best defined as

Accepted Answer

A piece of dead bone surrounded by infected tissue

Answer

A piece of dead bone without surrounding infection

Answer

A piece of bone with compromised blood supply

Answer

None of the options

Question 8

Which of the following statements about Pott's spine is false?

Accepted Answer

Always heals by chemotherapy

Answer

There is disc space narrowing on x-ray

Answer

Back pain is an early symptom

Answer

Commonest at dorsolumbar junction

Question 9

Which of the following conditions can cause locking of the knee joint?

Accepted Answer

Loose body in knee joint

Answer

Osgood Schlatter

Answer

Tuberculosis of knee

Answer

a and b both

Question 10

Triple deformity of the knee includes all except:

Accepted Answer

Medial rotation of tibia

Answer

Lateral rotation of tibia

Answer

Flexion

Answer

Posterior subluxation of tibia

Arthrology and Infections — MCQs

Arthrology and Infections — MCQs

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