Infection, Pharmacology & VTE MCQs

A 42-year-old man presents with an acutely swollen and erythematous right knee. Joint aspiration yields synovial fluid with a white blood cell count of 35,000/uL. Under polarized light microscopy with a red compensator, the crystals appear yellow when aligned parallel to the axis of the compensator. Which of the following is the most likely diagnosis?

A 2-week-old neonate presents with asymmetric skin folds, pseudoparalysis of the right leg, and pain with passive hip motion.

Ultrasound confirms a large joint effusion consistent with septic arthritis. Which pathogen is most uniquely common in this specific age group compared to older children?

A 4-week-old infant was diagnosed with neonatal septic arthritis of the hip. Treatment was delayed for several days prior to surgical drainage. A follow-up radiograph one year later shows complete absence of the proximal femoral epiphysis and neck.

This severe structural loss is primarily the result of which of the following pathophysiologic mechanisms?

A 35-year-old male with psoriatic arthritis has predominantly axial disease (spondylitis and sacroiliitis) that has remained highly active despite maximum doses of NSAIDs. According to current treatment guidelines, what is the preferred next step in pharmacologic management?

A 4-year-old child with Down syndrome presents with severe, symptomatic, flexible pes planovalgus that causes frequent tripping. Which of the following is the most appropriate initial management?

Differentiating acute Charcot neuroarthropathy from osteomyelitis can be challenging on MRI. Which of the following MRI findings is most specific for osteomyelitis rather than acute Charcot changes?

Which of the following is considered the gold standard for the definitive diagnosis of osteomyelitis in the setting of a chronic diabetic foot ulcer?

According to the Wagner classification system for diabetic foot ulcers, how is a Grade 3 lesion defined?

A diabetic foot wound extends entirely through the subcutaneous tissue, exposing the underlying flexor tendon and joint capsule. There is no clinical or radiographic evidence of osteomyelitis or deep abscess. According to the Wagner Classification system, what grade is this ulcer?

During the clinical evaluation of a diabetic plantar foot ulcer, the examiner uses a sterile blunt probe. The probe easily reaches a hard, gritty surface at the base of the wound. What is the clinical significance of a positive 'probe-to-bone' test in this setting?

While Total Contact Casting (TCC) is considered the gold standard for offloading non-infected neuropathic plantar foot ulcers, it is contraindicated in certain scenarios. Which of the following is considered an absolute contraindication to the application of a TCC?

Differentiating acute Charcot neuroarthropathy from pedal osteomyelitis on MRI can be challenging. Which of the following MRI findings most strongly favors a diagnosis of osteomyelitis over Charcot changes?

A 65-year-old poorly controlled diabetic presents with a deep, foul-smelling, necrotic foot ulcer accompanied by systemic inflammatory signs. He has a history of recent hospitalization and prior antibiotic use. Which of the following best represents the most appropriate empiric intravenous antibiotic coverage pending deep tissue cultures?

A 65-year-old male undergoes a two-stage revision for a chronic prosthetic joint infection. The organism isolated is Methicillin-sensitive Staphylococcus aureus. The success of targeted antibiotic therapy in this setting depends heavily on penetrating a biofilm. Which of the following antibiotics is most critical to include in the regimen for its unique anti-biofilm activity?

A 7-year-old child with sickle cell disease presents with fever, focal tibial pain, and swelling. MRI suggests diaphyseal osteomyelitis. Aspiration and blood cultures yield a Gram-negative, motile, non-lactose fermenting bacillus. What is the most appropriate directed antibiotic therapy?

When treating a periprosthetic joint infection caused by Staphylococcus aureus with retention of the hardware, rifampin is often added to the antibiotic regimen. What is the primary mechanism of action of rifampin?

In children, acute hematogenous osteomyelitis most frequently affects which specific anatomic region of the long bone?

In the pathogenesis of periprosthetic joint infections, what is the primary function of the bacterial glycocalyx?