This practice set contains high-yield board review questions covering key concepts in Infection, Pharmacology & VTE. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 181
Topic: Infection, Pharmacology & VTE
When comparing the outcomes of operative versus non-operative treatment with early functional rehabilitation for acute Achilles tendon ruptures, the current literature indicates that operative treatment is associated with:
Correct Answer & Explanation
. A similar re-rupture rate but a significantly higher risk of soft-tissue and wound complications
Explanation
Recent high-level evidence demonstrates that non-operative management utilizing an early functional rehabilitation protocol has re-rupture rates comparable to operative management. However, surgical treatment carries a significantly higher risk of wound infections and soft-tissue complications.
Question 182
Topic: Infection, Pharmacology & VTE
The most common pathogen for osteomyelitis of phalanges is:
Correct Answer & Explanation
. Staphylococcus aureus
Explanation
Staphylococcus aureus is the most common pathogen that causes osteomyelitis in the hand. Most cases of osteomyelitis in the hand are due to direct extension. Other pathogens can be found if there is a contaminated injury that penetrates directly into the bone. H. infuenza , mixed pathogens, and Pasturella multocida are less likely causes of osteomyelitis and are often caused by direct inoculation injuries or bites.
Question 183
Topic: Infection, Pharmacology & VTE
The most common pathogen causing septic arthritis in the hand is:
Correct Answer & Explanation
. Staphylococcus aureus
Explanation
Staphylococcus aureus is the most common pathogen that causes septic arthritis in the hand. The second most common pathogen is streptococcus species infections, which are often the result of trauma. Treatment includes incision and drainage with copius irrigation.
Question 184
Topic: Infection, Pharmacology & VTE
A 24-year-old man presents to the emergency department. He was bitten on his fist while fighting with another man. You notice teeth marks on the dorsum of the metacarpophalangeal (MC P) joint of the right middle finger. The bite does not appear to be deep because the joint is not exposed, and you can see the extensor tendon, which seems intact. The patient has active extension at the MC P joint. The wound is red and swollen, but there is no tenderness or redness on the volar aspect of the MCP joint. The patient has some limitation in range of motion. He is afebrile. Radiographs reveal soft tissue involvement but no joint dislocation or fracture, and there is no neurovascular deficit. An important step in assessment of human bites is:
Correct Answer & Explanation
. Evaluation for tendon injury in clenched-fist position
Explanation
Evaluation for tendon injury in a clenched-fist position is essential because tendons slide proximally in the open-hand position. Involvement of tendon or joint usually necessitates surgical debridement.C orrect Answer: Evaluation for tendon injury in clenched-fist position
Question 185
Topic: Infection, Pharmacology & VTE
A 24-year-old white man presents to the emergency department. He was bitten on his fist while fighting with another man. You notice teeth marks on the dorsum of the metacarpophalangeal (MC P) joint of the right middle finger. The bite does not appear to be deep because the joint is not exposed, and you can see the extensor tendon, which seems intact. The patient has active extension at the MC P joint. The wound is red and swollen, but there is no tenderness or redness on the volar aspect of the MCP joint. The patient has some limitation in range of motion. He is afebrile. Radiographs reveal soft tissue involvement but no joint dislocation or fracture, and there is no neurovascular deficit. The most appropriate antibiotic treatment includes:
Correct Answer & Explanation
. Imipenam and ciprofloxacin
Explanation
Imipenam and ciprofloxacin provide treatment for gram-negative and gram- positive organisms.C orrect Answer: Imipenam and ciprofloxacin
Question 186
Topic: Infection, Pharmacology & VTE
Which of the following medications is an effective alternative to intravenous vancomycin for the treatment of severe soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA):
Correct Answer & Explanation
. Linezolid
Explanation
Oral linezolid (600 mg twice a day) is an effective oral alternative to intravenous vancomycin. Below is a summary of a recent prospective, randomized study showing the efficacy of linezolid. Staphylococcus aureus complicates soft tissue and skin infections. Approximately 30% of S aureus infections are methicillinresistant. Although vancomycin has been the treatment of choice for MRSA, linezolid inhibits bacterial protein synthesis by blocking formation of the 70S initiation complex and can be administered orally, which is an advantage over vancomycin. This is a single-center study of adult patients. Investigators randomized 60 patients with S aureus (culture proven) to intravenous vancomycin or oral linezolid. The median length of therapy was 10 days. Seven patients in the vancomycin group required amputation, whereas no amputations were performed in the linezolid group. The median length of hospital stay was shorter in the linezolid group, and outpatient therapy was $100 per day less expensive (approximately $6,500 was saved on the hospital stay). A higher clinical cure rate (94%) was reported with the linezolid group compared to 84% with vancomycin. Linezolid is given orally, 600 mg every 12 hours, and it is well tolerated. No adverse effects were reported in this study. Other studies have had similar results. This is an important study for orthopedic surgeons because the number of patients presenting with MRSA infections is increasing. Athletes may be at an increased risk for the infection because of the potential for spread in locker rooms. This can be a limb-threatening infection and must be taken seriously.
Question 187
Topic: Infection, Pharmacology & VTE
The mechanism of action of linezolid is:
Correct Answer & Explanation
. Inhibition of the 70S initiation complex
Explanation
Oral linezolid (600 mg twice a day) is an effective oral alternative to intravenous vancomycin. Below is a summary of a recent prospective, randomized study showing the efficacy of linezolid. Staphylococcus aureus complicates soft tissue and skin infections. Approximately 30% of S aureus infections are methicillinresistant. Although vancomycin has been the treatment of choice for methicillin- resistant S aureus (MRSA), linezolid inhibits bacterial protein synthesis by blocking formation of the 70S initiation complex and can be administered orally, which is an advantage over vancomycin. This is a single-center study of adult patients. Investigators randomized 60 patients with S aureus (culture proven) to intravenous vancomycin or oral linezolid. The median length of therapy was 10 days. Seven patients in the vancomycin group required amputation, whereas no amputations were performed in the linezolid group. The median length of hospital stay was shorter in the linezolid group, and outpatient therapy was $100 per day less expensive (approximately $6,500 was saved on the hospital stay). A higher clinical cure rate (94%) was reported with the linezolid group compared to 84% with vancomycin. Linezolid is given orally, 600 mg every 12 hours, and it is well tolerated. No adverse effects were reported in this study. Other studies have had similar results. This is an important study for orthopedic surgeons because the number of patients presenting with MRSA infections is increasing. Athletes may be at an increased risk for the infection because of the potential for spread in locker rooms. This can be a limb-threatening infection and must be taken seriously.
Question 188
Topic: Infection, Pharmacology & VTE
A 25-year-old minor league baseball player has a severe soft tissue infection on the sole of his foot. The infection has not responded to oral cephalexin. There is 4 cm of surrounding erythema and induration, and a small amount of exudate can be expressed. The most likely organism is:
Correct Answer & Explanation
. Methicillin-resistant S aureus (MRSA)
Explanation
Staphylococcus aureus complicates soft tissue and skin infections. Approximately 30% of S aureus infections are methicillinresistant. Although vancomycin has been the treatment of choice for MRSA, linezolid inhibits bacterial protein synthesis by blocking formation of the 70S initiation complex and can be administered orally, which is an advantage over vancomycin. This is a single-center study of adult patients. Investigators randomized 60 patients with S aureus (culture proven) to intravenous vancomycin or oral linezolid. The median length of therapy was 10 days. Seven patients in the vancomycin group required amputation, whereas no amputations were performed in the linezolid group. The median length of hospital stay was shorter in the linezolid group, and outpatient therapy was $100 per day less expensive (approximately $6,500 was saved on the hospital stay). A higher clinical cure rate (94%) was reported with the linezolid group compared to 84% with vancomycin. Linezolid is given orally, 600 mg every 12 hours, and it is well tolerated. No adverse effects were reported in this study. Other studies have had similar results. This is an important study for orthopedic surgeons because the number of patients presenting with MRSA infections is increasing. Athletes may be at an increased risk for the infection because of the potential for spread in locker rooms. This can be a limb-threatening infection and must be taken seriously.
Question 189
Topic: Infection, Pharmacology & VTE
A 4-year-old boy presents with an acute limp, fever of 38.8°C, refusal to bear weight, and a WBC count of 14,000/mm³. According to the Kocher criteria, what is the approximate probability that this child has septic arthritis of the hip?
Correct Answer & Explanation
. Approximately 93%
Explanation
The Kocher criteria evaluate four predictors: non-weight-bearing, ESR >40 mm/hr, fever >38.5°C, and WBC >12,000/mm³. Having three of these four predictors yields a 93% probability of septic arthritis.
Question 190
Topic: Infection, Pharmacology & VTE
A 60-year-old patient with poorly controlled diabetes presents with a deep, non-healing plantar ulcer probing to bone. MRI confirms osteomyelitis of the first metatarsal head. Which of the following is the most definitive method to identify the causative organism and direct targeted antibiotic therapy?
Correct Answer & Explanation
. Bone biopsy for culture and histology
Explanation
Bone biopsy is the gold standard for diagnosing osteomyelitis and accurately directing pathogen-specific antibiotic therapy. Superficial swabs often isolate colonizing flora rather than the true bone pathogen, leading to inadequate treatment.
Question 191
Topic: Infection, Pharmacology & VTE
A 4-year-old boy presents with refusal to bear weight on his right leg. He has a temperature of 38.8°C (101.8°F), an ESR of 50 mm/hr, and a WBC count of 14,000/mm³. Based on Kocher's criteria, what is the approximate probability that this child has septic arthritis of the hip?
Correct Answer & Explanation
. 93%
Explanation
Kocher's criteria include non-weight-bearing, fever >38.5°C, ESR >40, and WBC >12,000. With all 4 criteria present, the predicted probability of septic arthritis is approximately 99%.
Question 192
Topic: Infection, Pharmacology & VTE
A 4-year-old child presents with hip pain and a limp. According to the original Kocher criteria used to differentiate septic arthritis from transient synovitis, which of the following is NOT one of the four classic predictive variables?
Correct Answer & Explanation
. Serum C-reactive protein (CRP) > 2.0 mg/dL
Explanation
The original four Kocher criteria are non-weight-bearing status, ESR > 40 mm/hr, temperature > 38.5 C (101.3 F), and WBC count > 12,000/mm^3. Although CRP is highly sensitive and was added to modified algorithms later, it was not one of the original four parameters.
Question 193
Topic: Infection, Pharmacology & VTE
Post-operatively, the patient was prescribed protected weight-bearing (toe-touch or 20% partial weight-bearing) for 6 weeks. What is the most critical reason for this specific weight-bearing restriction in this complex revision THA?
Correct Answer & Explanation
. To allow for bone ingrowth and healing of the acetabular augment fixation and trochanteric osteotomy.
Explanation
Correct Answer: CThe post-operative protocol section explicitly states: 'Protected weight-bearing (toe-touch or 20% partial weight-bearing) using crutches or a walker was prescribed due to the extensive acetabular reconstruction with augments and femoral impaction grafting. This protocol is crucial to allow for bone ingrowth and healing of the acetabular augment fixation and trochanteric osteotomy.' While pain management (Option A) is important, it's not the primary reason for the specific weight-bearing restriction. DVT prophylaxis (Option B) is managed pharmacologically and with early mobilization, not primarily by weight-bearing restrictions. While preventing dislocation (Option D) is a concern, it's addressed by hip precautions and stability testing, not primarily by protected weight-bearing in this context. Early ROM (Option E) is performed within precautions, but protected weight-bearing is about protecting the healing bone-implant interface. Therefore, allowing for bone ingrowth and healing of the acetabular augment fixation and trochanteric osteotomy is the most critical reason.
Question 194
Topic: Infection, Pharmacology & VTE
A 72-year-old male with a history of chronic obstructive pulmonary disease and coronary artery disease sustains an L1 burst fracture. He is neurologically intact. The TLICS score is 2. The patient's medical comorbidities make him a high-risk surgical candidate. Based on the case's discussion of postoperative rehabilitation protocols, what is the most appropriate immediate postoperative management strategy if he were to undergo surgical stabilization?
Correct Answer & Explanation
. Early mobilization out of bed on postoperative day one, with deep vein thrombosis prophylaxis and physical therapy focusing on transfers and ambulation.
Explanation
Correct Answer: CThe case explicitly states under 'Post Operative Rehabilitation Protocols': 'The traditional paradigm of prolonged bed rest has been universally abandoned due to the unacceptable rates of deep vein thrombosis, pulmonary embolism, atelectasis, and deconditioning. Patients who have undergone rigid internal fixation are typically mobilized out of bed on postoperative day one.' It also emphasizes, 'Deep vein thrombosis prophylaxis is paramount. Mechanical prophylaxis (pneumatic compression devices) is initiated immediately. Chemical prophylaxis (e.g., Low Molecular Weight Heparin) is typically started 24 to 48 hours postoperatively...' and 'Physical therapy focuses on transfers, ambulation, and isometric core strengthening.'Option A is incorrectbecause prolonged bed rest is explicitly stated as an abandoned paradigm due to high complication rates.Option B is incorrectbecause the case states that 'the use of a Thoracolumbosacral Orthosis following surgical stabilization is highly debated... modern pedicle screw constructs offer sufficient biomechanical rigidity that bracing is often unnecessary.' While it might be used as a tactile reminder, it's not a universal requirement, and ambulation is encouraged, not restricted.Option D is incorrectbecause 'Active range of motion exercises for the spine are generally restricted until radiographic evidence of early bony union is observed, typically around the 8 to 12-week mark.'Option E is incorrectbecause chemical DVT prophylaxis is typically started 24-48 hours postoperatively, not delayed until 72 hours, to mitigate the risk of DVT/PE.
Question 195
Topic: Infection, Pharmacology & VTE
A 38-year-old male presents to the emergency department 10 hours after sustaining a laceration over the dorsum of his dominant right hand during an altercation. He admits to striking another individual in the mouth. On examination, a 1.5 cm transverse laceration is noted over the metacarpophalangeal (MCP) joint of the middle finger. There is moderate swelling, tenderness, and pain with passive flexion of the digit. Plain radiographs are obtained and show no fracture or foreign body. Given these findings, which of the following is the most appropriate next step in management?
Correct Answer & Explanation
. C. Admit for intravenous broad-spectrum antibiotics and emergent surgical irrigation and debridement with joint exploration.
Explanation
Correct Answer: CThe patient's presentation (laceration over an MCP joint after striking a mouth, pain with passive flexion, swelling, and tenderness) is highly suspicious for a 'fight bite' with potential septic arthritis of the MCP joint. Even in the absence of a visible foreign body or fracture on X-ray, the mechanism and clinical signs strongly suggest joint capsule penetration and deep infection. Emergent surgical irrigation and debridement with joint exploration is the standard of care for suspected septic arthritis or deep space infection from a human bite. This allows for thorough debridement of devitalized tissue, removal of any missed foreign bodies, and copious irrigation of the joint space. Intravenous broad-spectrum antibiotics should be initiated promptly. Oral antibiotics alone (A) are insufficient for deep infections. Discharging the patient (A, B) without definitive surgical management is dangerous and can lead to rapid joint destruction. While joint aspiration (D) can confirm septic arthritis, it should not delay definitive surgical management once clinically suspected. Primary closure of the wound (E) is contraindicated in contaminated human bite wounds due to the high risk of trapping infection.
Question 196
Topic: Infection, Pharmacology & VTE
A 45-year-old male presents with a 3-day history of worsening pain, swelling, and redness over the dorsum of his hand following a fight. He has a small, punctate wound over the third MCP joint. X-rays show no fracture or foreign body. Examination reveals significant swelling, warmth, and exquisite pain with any passive movement of the third MCP joint. He also reports a fever of 38.8°C. Which of the following is the most appropriate empiric intravenous antibiotic regimen, assuming no known allergies?
Correct Answer & Explanation
. B. Amoxicillin-clavulanate (Augmentin)
Explanation
Correct Answer: BThe patient's presentation is highly suggestive of septic arthritis of the MCP joint, a severe complication of a fight bite. Empiric intravenous antibiotics are crucial. Amoxicillin-clavulanate (Augmentin) is the first-line empiric antibiotic for human bite infections. It provides excellent broad-spectrum coverage against the characteristic polymicrobial flora of human bites, including common aerobes (Staphylococcus, Streptococcus) and anaerobes (Bacteroides, Fusobacterium, Peptostreptococcus), as well as the fastidious Gram-negative rodEikenella corrodens. Ciprofloxacin and Rifampin (A) lack adequate anaerobic coverage. Doxycycline and Metronidazole (C) also have gaps in coverage for the typical fight bite pathogens. Cephalexin (D) has good Gram-positive coverage but lacks activity against anaerobes andEikenella. Vancomycin and Gentamicin (E) are typically reserved for more severe, resistant, or nosocomial infections, with Vancomycin targeting MRSA and Gentamicin providing Gram-negative coverage, but this combination is not optimal for initial empiric human bite coverage.
Question 197
Topic: Infection, Pharmacology & VTE
During surgical exploration of a 'fight bite' over the fifth MCP joint, purulent material is found tracking along the extensor digitorum communis tendon into the wrist. This finding is most indicative of which specific complication?
Correct Answer & Explanation
. C. Tenosynovitis of the extensor tendon sheath
Explanation
Correct Answer: CPurulent material tracking along a tendon, especially into the wrist, is a classic sign of tenosynovitis, which is an infection of the tendon sheath. The extensor digitorum communis tendon is involved here. While other pathologies like septic arthritis (B) and osteomyelitis (D) can coexist or develop from tenosynovitis, the direct observation of pus within the tendon sheath extending proximally confirms tenosynovitis. Cellulitis (A) is a superficial soft tissue infection. A localized abscess (E) would be a circumscribed collection of pus, but its extension along a tendon sheath points specifically to tenosynovitis.
Question 198
Topic: Infection, Pharmacology & VTE
A 60-year-old diabetic patient presents with a fight bite over the fifth MCP joint, 24 hours after injury. Clinically, there is significant erythema, swelling, and purulent discharge. He has a history of penicillin allergy (anaphylaxis). Which intravenous antibiotic combination is most appropriate for initial empiric coverage?
Correct Answer & Explanation
. C. Clindamycin and Ciprofloxacin
Explanation
Correct Answer: CGiven the patient's history of penicillin allergy (anaphylaxis), beta-lactam antibiotics like Ampicillin-sulbactam (A) and Piperacillin-tazobactam (D) are contraindicated. Cefazolin (B) is a first-generation cephalosporin, which has some cross-reactivity risk with penicillin, and when combined with Metronidazole, lacks full Gram-negative coverage for organisms likeEikenella. Clindamycin provides good coverage against anaerobes and Gram-positives (Staph/Strep). Ciprofloxacin provides good coverage against Gram-negatives, includingEikenella corrodens. This combination (Clindamycin and Ciprofloxacin) is a suitable and commonly used alternative for a penicillin-allergic patient with a severe human bite infection. Vancomycin (E) would cover MRSA and Gram-positives, and Aztreonam covers Gram-negatives includingEikenella, but this combination is often reserved for resistant organisms or specific scenarios. Clindamycin and Ciprofloxacin is a common and effective alternative.
Question 199
Topic: Infection, Pharmacology & VTE
What is the primary differentiating feature between cellulitis and a deep-seated infection (e.g., septic arthritis) in a hand with a fight bite?
Correct Answer & Explanation
. C. Significant pain with passive range of motion of the affected joint, disproportionate to superficial findings.
Explanation
Correct Answer: CWhile redness and warmth (A), elevated WBC count (B), and duration of symptoms (E) can be present in both cellulitis and deep infections, significant pain with passive range of motion (PROM) of the affected joint, especially if disproportionate to superficial findings, is the hallmark sign differentiating a deep-seated joint infection (septic arthritis) from isolated cellulitis. Cellulitis primarily involves the superficial soft tissues, while septic arthritis directly affects the joint capsule, making any movement excruciating due to stretching of the inflamed synovium. The size of the laceration (D) is not a reliable differentiator for depth of infection.
Question 200
Topic: Infection, Pharmacology & VTE
The radiograph below shows a severely displaced, comminuted fracture of the proximal third of the tibial diaphysis. This specific deformity pattern, characterized by apex anterior (procurvatum) and apex lateral (valgus) angulation, is classic for proximal third tibial fractures. Which of the following is the primary deforming force responsible for the apex anterior angulation of the proximal fragment?
Correct Answer & Explanation
. Unopposed pull of the extensor mechanism (quadriceps via patellar tendon)
Explanation
Correct Answer: CThe case explicitly states, 'This specific deformity pattern is classic for proximal third tibial fractures and is driven by the unopposed pull of the extensor mechanism (quadriceps via the patellar tendon) on the proximal fragment, drawing it into extension.' The patellar tendon inserts onto the tibial tubercle, which is part of the proximal fragment. When the tibia fractures proximally, the quadriceps muscle, acting through the patellar tendon, pulls the proximal fragment anteriorly and into extension, creating the apex anterior (procurvatum) deformity.Option A (Gastrocnemius muscle pull)andOption B (Soleus muscle pull)primarily act on the ankle (plantarflexion) and are attached more distally or posteriorly, contributing to shortening or posterior displacement of the distal fragment, but not the apex anterior deformity of the proximal fragment.Option D (Pes anserinus muscle group pull)andOption E (Iliotibial band tension)exert variable varus/valgus and rotational forces on the proximal tibia, contributing to the apex lateral (valgus) deformity, but not the primary apex anterior angulation.
Test Yourself
Switch to an interactive, timed exam simulation to truly master this topic.