Arthrology and Infections Practice Questions

Q: Which of the following is true regarding osteomyelitis in newborns?

Most common in diaphysis. ***Most common in diaphysis*** - In neonates, **osteomyelitis** frequently affects the **diaphysis and metaphysis of long bones** due to differences in vascular supply and bone structure compared to older children and adults. - The **metaphyseal growth plate** acts as a barrier in older children, but in neonates, vessels often cross this plate, allowing infection to spread into the diaphysis and epiphysis. - This is the **characteristic feature** of neonatal osteomyelitis. *Most common organism is E.coli* - The **most common causative organism** for neonatal osteomyelitis is **Staphylococcus aureus** (50-60% of cases), not *E. coli*. - *E. coli* can cause neonatal osteomyelitis but is much less frequent than *Staphylococcus aureus* or Group B Streptococcus. *The infection is unifocal* - Neonatal osteomyelitis is characteristically **multifocal** in **30-40% of cases**, meaning it affects **multiple bones** simultaneously. - This is in contrast to older children and adults, where osteomyelitis tends to be unifocal (single site). *Organisms are derived from maternal genital tract* - While **Group B Streptococcus** (the second most common organism) can be acquired from the maternal genital tract during delivery, **Staphylococcus aureus** (the most common organism) is typically acquired **postnatally** from the hospital environment, skin colonization, or via indwelling catheters. - The **primary route** for neonatal osteomyelitis is **hematogenous spread** from bacteremia, rather than direct ascending infection from the birth canal. - Since S. aureus accounts for the majority of cases and is not maternally derived, this statement is not the best characterization of neonatal osteomyelitis.

Q: Which of the following statements is true regarding osteomyelitis?

Recurrence is a common complication. ***Recurrence is a common complication*** - **Osteomyelitis** can be challenging to eradicate due to the formation of a **biofilm** by bacteria, making treatment difficult and leading to high recurrence rates. - Inadequate debridement of infected bone and poor antibiotic penetration into **ischemic or necrotic bone** contribute to the persistence of infection. *Is not associated with other bony/cartilaginous injury* - **Osteomyelitis** often arises as a complication of **trauma**, **surgery**, or **open fractures**, where bacteria directly enter the bone. - Conditions like **diabetic foot ulcers** or **pressure sores** can also lead to contiguous spread of infection to bone, making it associated with soft tissue and bony injury. *Common in children and rare in adults* - While **acute hematogenous osteomyelitis** is more common in children, **osteomyelitis** in adults is frequently associated with **diabetes**, **vascular insufficiency**, or **surgical procedures**. - The incidence in adults, particularly chronic forms, is substantial and not rare. *May be overlooked as clinically occult* - **Osteomyelitis** can present with **vague symptoms** such as non-specific pain or swelling, sometimes mimicking other conditions like simple sprains or arthritis. - In cases of **chronic osteomyelitis**, symptoms may be intermittent or low-grade, leading to diagnostic delays and the infection being "occult" or hidden.

Q: Avascular necrosis is seen in:

Both corticosteroid use and alcoholism. ***Both corticosteroid use and alcoholism*** - Long-term **corticosteroid use** is a well-established risk factor for avascular necrosis, particularly affecting the femoral head. - **Chronic alcoholism** is also strongly associated with avascular necrosis due to its effects on lipid metabolism and microcirculation. *Corticosteroid use* - While corticosteroid use is a known cause, this option is incomplete as it omits other significant risk factors. - Steroid-induced AVN is thought to be related to **lipid emboli** or direct damage to osteocytes. *Alcoholism* - Alcoholism does contribute to avascular necrosis by affecting **fat metabolism** and disrupting blood flow. - However, this option is also incomplete as it does not include other major causes such as corticosteroid use. *Trauma only* - While **trauma** (e.g., femoral neck fracture) is a significant cause of avascular necrosis due to disruption of blood supply, it is not the *only* cause. - Many cases of avascular necrosis, especially in the hip, are **non-traumatic** and linked to systemic risk factors.

Q: The primary pharmacological intervention to retard avascular necrosis progression is?

Bisphosphonates (Alendronate). ***Bisphosphonates (Alendronate)*** - **Bisphosphonates** inhibit osteoclast-mediated bone resorption and reduce bone cell death, showing promise in preventing progression of early-stage **avascular necrosis**. [1] - Alendronate specifically has been studied for its **bone-preserving effects** in AVN by maintaining bone architecture and potentially slowing femoral head collapse. *Corticosteroid therapy* - **Corticosteroids** are a major **risk factor** for developing avascular necrosis, not a treatment for it. - They cause AVN through mechanisms including **fat embolism**, increased **intraosseous pressure**, and direct **osteocyte toxicity**. *High-dose calcium supplementation* - **Calcium supplementation** supports general bone health but does not address the underlying **vascular disruption** in AVN. - No evidence exists that calcium alone can retard **AVN progression**, which involves interruption of blood supply leading to bone death. *Vitamin D supplementation alone* - **Vitamin D** is essential for calcium absorption and bone mineralization but does not target **AVN pathophysiology**. - Like calcium, it does not address the primary mechanism of **blood supply disruption** that characterizes avascular necrosis.

Q: Tardy ulnar neuritis may be due to

Cubitus valgus deformity. ***Cubitus valgus deformity*** - A cubitus valgus deformity increases the carrying angle of the elbow, which places abnormal **tensile stress** on the **ulnar nerve** behind the medial epicondyle. - This chronic stretching and pressure can lead to delayed onset (tardy) neuropathy, presenting as ulnar neuritis. *Advanced osteoarthritis of elbow* - While osteoarthritis can affect the elbow, it primarily involves the **articular cartilage** and bony changes within the joint, not typically directly compressing or stretching the ulnar nerve in a chronic, "tardy" fashion unless severe osteophytes directly impinge it. - The direct link to stretching and chronic irritation of the ulnar nerve as a primary cause of **tardy ulnar neuritis** is more strongly associated with structural deformities like cubitus valgus. *Both of the options* - While severe osteoarthritis could theoretically contribute to ulnar nerve compression through osteophyte formation, **cubitus valgus deformity** is a much more classic and direct cause of **tardy ulnar neuritis** due to the chronic mechanical stretch it places on the nerve. - This option is incorrect because cubitus valgus is the primary and most common long-term cause of tardy ulnar neuritis, making the inclusion of advanced osteoarthritis as equally causative less accurate in this context without further specifying direct nerve involvement. *None of the options* - This option is incorrect because **cubitus valgus deformity** is a recognized and common cause of tardy ulnar neuritis. - The valgus angulation creates a sustained tension and potential irritation of the ulnar nerve, leading to delayed onset symptoms.

Q: Early movement following surgery for ankylosis is

Desirable. ***Desirable*** - Early movement following surgery for **ankylosis** is crucial for preventing **re-ankylosis** and promoting the formation of a **neocartilage-like layer**. - It helps maintain joint mobility, reduce stiffness, and improves long-term functional outcomes after procedures like **arthroplasty**. *Harmful* - Delays in movement can lead to increased fibrous tissue formation, limiting the newly created joint's mobility and potentially causing **re-ankylosis**. - Prolonged immobilization after joint surgery can also lead to muscle atrophy, contractures, and impaired circulation, hindering recovery. *Indicated only when ankylosis is one sided* - The principle of early movement applies to both **unilateral** and **bilateral ankylosis** to prevent recurrence and improve range of motion in the affected joint(s). - Focusing solely on unilateral cases overlooks the functional benefits of early mobilization for all patients undergoing such surgery. *Unimportant* - Early movement is a **critical component** of postoperative recovery, as it directly impacts the success of the surgical intervention by maintaining joint space and flexibility. - Neglecting early motion can compromise the surgical outcome, increasing the risk of stiffness, pain, and the need for further interventions.

Q: The commonest cause of spinal or joint infection in a young person is -

Tuberculosis. ***Tuberculosis*** - In a young person, especially in endemic areas, **spinal tuberculosis (Pott's disease)** and **tuberculous arthritis** are significant causes of joint and spinal infections [1]. - Tuberculosis can lead to **chronic osteomyelitis** and **destructive arthritis**, often with a more insidious onset than acute bacterial infections [1]. *Gonococcal* - **Gonococcal arthritis** typically presents as an acute, migratory polyarthritis or tenosynovitis, or as a septic arthritis, usually affecting one or two large joints. - While it is a common cause of septic arthritis in sexually active young adults, it is less likely to be the **commonest cause of chronic spinal or joint infection** compared to tuberculosis. *Staphylococcus aureus* - **Staphylococcus aureus** is the most common cause of acute **septic arthritis** and **vertebral osteomyelitis** in adults across all age groups. - However, for "spinal or joint infection" in a young person, especially in a chronic or indolent presentation, **tuberculosis** might be more prevalent in certain populations and regions. *Syphilis* - **Syphilis** can cause joint manifestations, particularly in congenital syphilis and tertiary syphilis (e.g., **Charcot joint** from neurosyphilis). - These presentations are less common overall as a direct infectious cause of joint or spinal infection in young people compared to tuberculosis or acute bacterial infections.

Q: A 45-year-old was given steroids after renal transplant. After 2 years he had difficulty in walking and pain in both hips. Which one of the following is most likely cause?

Avascular necrosis. ***Avascular necrosis*** - Chronic **steroid use**, especially after organ transplantation, is a major risk factor for avascular necrosis (AVN) due to impaired blood supply to bone, particularly in the femoral head. - **Hip pain** and **difficulty walking** are classic symptoms of AVN, which can lead to collapse of the femoral head if untreated. *Tuberculosis* - While tuberculosis can affect bones and joints (**Pott's disease**), it typically presents with more systemic symptoms like fever, weight loss, and night sweats, which are not mentioned. - Skeletal TB often affects the spine more commonly and usually presents with granulomatous inflammation and bone destruction rather than isolated joint pain in the hips *Primary Osteoarthritis* - Primary osteoarthritis is typically an **age-related degenerative joint disease** occurring in older individuals, and while it causes hip pain, it is not directly linked to steroid use in a 45-year-old. - The onset of pain in this scenario, following long-term steroid use, strongly points away from primary osteoarthritis as the primary driving factor. *Aluminum toxicity* - Aluminum toxicity can occur in patients with **renal failure** and can cause **osteomalacia** or **dialysis encephalopathy**. - Its presentation typically involves bone pain, fractures, and neurological symptoms, but it does not specifically cause avascular necrosis of the femoral head as seen with steroid use.

Q: Most common cause of AVN of the hip is -

Idiopathic. ***Idiopathic*** - The most common cause of **avascular necrosis (AVN)** of the hip is **idiopathic**, meaning no specific underlying cause can be identified. - While many risk factors are associated with AVN, a significant proportion of cases occur without a clear etiology, making **idiopathic AVN** the most frequent presentation. *Corticosteroid use* - **Corticosteroid use** is a major **risk factor** for AVN, but it is not the most common cause overall, as not all cases are associated with steroid exposure. - Long-term use of **high-dose corticosteroids** can disrupt blood supply to the bone by various mechanisms, including **fat emboli** and **vasoconstriction**. *Alcoholism* - **Alcoholism** is another significant **risk factor** for AVN, contributing to a substantial number of cases. - Excessive alcohol consumption can lead to **fatty liver disease** and fat emboli, which can obstruct the blood vessels supplying the femoral head. *Fracture neck of femur* - A **fracture of the neck of the femur** is a well-known cause of **traumatic AVN** due to damage to the blood supply, particularly the **medial circumflex femoral artery**. - However, when considering all causes, including non-traumatic forms, fractures represent a specific subgroup rather than the overall most common cause.

Question 1

Which of the following is true regarding osteomyelitis in newborns?

Accepted Answer

Most common in diaphysis

Answer

Most common organism is E.coli

Answer

The infection is unifocal

Answer

Organisms are derived from maternal genital tract

Question 2

Which of the following statements is true regarding osteomyelitis?

Accepted Answer

Recurrence is a common complication

Answer

Is not associated with other bony/cartilagionus injury

Answer

Common in children and rare in adults

Answer

May be overlooked as clinically occult

Question 3

Avascular necrosis is seen in:

Accepted Answer

Both corticosteroid use and alcoholism

Answer

Corticosteroid use

Answer

Alcoholism

Answer

Trauma only

Question 4

The primary pharmacological intervention to retard avascular necrosis progression is?

Accepted Answer

Bisphosphonates (Alendronate)

Answer

High-dose calcium supplementation

Answer

Vitamin D supplementation alone

Answer

Corticosteroid therapy

Question 5

Tardy ulnar neuritis may be due to

Accepted Answer

Cubitus valgus deformity

Answer

Advanced osteoarthritis of elbow

Answer

Both of the options

Answer

None of the options

Question 6

Early movement following surgery for ankylosis is

Accepted Answer

Desirable

Answer

Harmful

Answer

Indicated only when ankylosis is one sided

Answer

Unimportant

Question 7

The commonest cause of spinal or joint infection in a young person is -

Accepted Answer

Tuberculosis

Answer

Gonococcal

Answer

Staphylococcus aureus

Answer

Syphilis

Question 8

A patient with known hemophilia presented with pain in his ankle. X-ray showed an osteolytic lesion with a sclerotic rim. What is your diagnosis?

Accepted Answer

PVNS

Answer

Hemophilic pseudotumor

Answer

Giant Cell Tumor

Answer

Ochronosis

Question 9

A 45-year-old was given steroids after renal transplant. After 2 years he had difficulty in walking and pain in both hips. Which one of the following is most likely cause?

Accepted Answer

Avascular necrosis

Answer

Tuberculosis

Answer

Primary Osteoarthritis

Answer

Aluminum toxicity

Question 10

Most common cause of AVN of the hip is -

Accepted Answer

Idiopathic

Answer

Corticosteroid use

Answer

Alcoholism

Answer

Fracture neck of femur

Arthrology and Infections — MCQs

Arthrology and Infections — MCQs

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