Infection, Pharmacology & VTE MCQs

A 58-year-old male presents with acute onset of severe pain, redness, and swelling in his great toe. He reports a history of similar episodes, often after consuming alcohol or red meat. Aspiration of the MTP joint reveals negatively birefringent needle-shaped crystals. What is the most appropriate long-term management to prevent recurrent attacks?

A 75-year-old female with a history of diffuse idiopathic skeletal hyperostosis (DISH), Parkinson's disease, and previous right THA (now undergoing left THA) is identified as high risk for heterotopic ossification (HO). Which of the following is the most effective prophylactic measure against severe HO after THA?

A 78-year-old male with a history of hypertension and atrial fibrillation on warfarin presents for a scheduled revision THA due to recurrent dislocations of his primary THA. His INR is 2.8. What is the most appropriate management of his anticoagulation in the perioperative period?

A 58-year-old diabetic male with severe peripheral neuropathy presents with a warm, swollen, erythematous left foot that developed over the past week, with no history of acute trauma. Radiographs show subtle disorganization of the midfoot joints, particularly the talonavicular and naviculocuneiform joints, with early fragmentation and joint subluxation. There is no evidence of osteomyelitis on initial X-rays. What is the most critical immediate management strategy?

A 48-year-old male undergoes arthroscopic knee surgery for a chronic meniscal tear. Postoperatively, he develops a warm, swollen, and painful knee. Joint aspiration reveals cloudy fluid with a leukocyte count of 90,000 cells/µL, 95% neutrophils, and positive Gram stain for Gram-positive cocci in clusters. What is the MOST appropriate initial management step?

A 55-year-old male with a history of intravenous drug use presents with persistent left proximal tibial pain, swelling, and purulent drainage from a sinus tract for 6 months. Radiographs show periosteal reaction, cortical thickening, and a sequestrum within the tibial metaphysis. Cultures from the sinus tract grew Staphylococcus aureus. What is the most important pathological feature that contributes to the chronicity and difficulty in treating this osteomyelitis?

A 55-year-old male with long-standing diabetes presents with acute onset of swelling, redness, and pain in his midfoot, following a minor twist. Radiographs show extensive disorganization of the tarsometatarsal joints, fragmentation, and bone resorption, without obvious signs of infection. White blood cell count and ESR/CRP are mildly elevated but non-specific. What is the most appropriate initial management strategy?

Biofilm formation on orthopedic implants is a significant cause of periprosthetic joint infection. Which of the following is a key characteristic of bacteria within a biofilm that contributes to their increased resistance to antibiotics and host immune responses?

A patient develops a chronic periprosthetic joint infection (PJI) resistant to conventional antibiotic therapy. The persistence of the infection is largely attributed to the formation of a bacterial biofilm on the implant surface. Which component of the biofilm matrix is primarily responsible for protecting bacteria from host immune defenses and antibiotics, contributing to treatment failure?

Biofilm formation on orthopedic implants is a major cause of periprosthetic joint infection (PJI). A critical component that allows bacteria to evade host immunity and antibiotic penetration within a biofilm is the:

During implant-associated infections, bacteria often form biofilms. Which of the following is a key characteristic of biofilm-dwelling bacteria that contributes significantly to their increased resistance to antibiotics and host immune responses?

A 19-year-old male suffers a gunshot wound to the right knee. Radiographs reveal a retained bullet lying entirely within the intra-articular space of the knee. The patient has no other systemic injuries, and the soft tissue wounds are small and clean. Which of the following is an absolute indication for the surgical retrieval of this bullet?

A surgeon uses the medial approach to the knee to perform an opening wedge high tibial osteotomy. The superficial medial collateral ligament (sMCL) is located deep to which of the following structures?

A 70-year-old male is diagnosed with a chronic periprosthetic joint infection of the hip caused by Staphylococcus epidermidis. The bacteria have formed a robust glycocalyx (biofilm) on the implant surface. Which of the following systemic antibiotics has the highest efficacy in penetrating the staphylococcal biofilm?

A patient undergoes a surgical procedure with a peripheral nerve block using bupivacaine. During the injection, the patient inadvertently receives an intravascular dose and suddenly develops perioral numbness, tinnitus, metallic taste, and subsequently ventricular tachycardia. What is the most appropriate initial specific pharmacologic antidote?

A postoperative orthopedic patient receiving unfractionated heparin for DVT prophylaxis experiences a 50% drop in platelet count on postoperative day 6, complicated by a new symptomatic deep vein thrombosis. What is the underlying mechanism of this paradoxical thrombotic state?

In the context of periprosthetic joint infection (PJI), staphylococcal species frequently form biofilms on orthopedic implants. Which of the following best describes the critical transition step in the formation of a mature, antibiotic-resistant biofilm?