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Question 7601

Topic: 2. Trauma

A 30-year-old polytrauma patient develops petechiae, confusion, and hypoxemia 48 hours after sustaining bilateral femur fractures. What is the most likely underlying pathophysiologic mechanism for this syndrome?

. Deep vein thrombosis causing a pulmonary embolus
. Disseminated intravascular coagulation
. Intravascular fat macroglobules causing mechanical obstruction and endothelial damage
. Aspiration pneumonia
. Acute respiratory distress syndrome secondary to fluid overload

Correct Answer & Explanation

. Deep vein thrombosis causing a pulmonary embolus


Explanation

The classic triad of Fat Embolism Syndrome (FES) includes hypoxemia, neurologic abnormalities, and a petechial rash. It is caused by fat emboli creating both mechanical occlusion and biochemical endothelial injury.

Question 7602

Topic: Lower Extremity Trauma

A 38-year-old man undergoes open reduction and internal fixation of a Schatzker IV (medial) tibial plateau fracture.

Which surgical approach is most appropriate for direct visualization and buttress plating of the posteromedial fragment?

. Anterolateral approach
. Direct anterior approach
. Posteromedial approach between the pes anserinus and medial gastrocnemius
. Posterolateral approach
. Midline longitudinal approach

Correct Answer & Explanation

. Anterolateral approach


Explanation

The posteromedial approach allows direct visualization and application of an anti-glide or buttress plate to the apex of the posteromedial fragment, effectively resisting the shear forces.

Question 7603

Topic: 2. Trauma

A 22-year-old male presents with a highly comminuted, severely shortened distal radius fracture and an associated ipsilateral diaphyseal ulna fracture after a high-speed motorcycle crash. He requires multiple surgeries for other life-threatening injuries. What is the most appropriate temporary or definitive construct for the wrist?

. Dorsal spanning bridge plate
. Volar locking plate
. Fragment-specific fixation
. Percutaneous pinning
. Short arm cast

Correct Answer & Explanation

. Dorsal spanning bridge plate


Explanation

A dorsal spanning bridge plate is ideal for highly comminuted distal radius fractures or in polytrauma patients requiring immediate upper extremity weight-bearing and rapid surgical stabilization.

Question 7604

Topic: 2. Trauma

A 35-year-old male requires open reduction and internal fixation of a displaced posteromedial tibial plateau fracture. A posteromedial approach is utilized. Which of the following structures is at greatest risk of iatrogenic injury during the superficial dissection?

. Common peroneal nerve
. Saphenous nerve
. Sural nerve
. Tibial nerve
. Popliteal artery

Correct Answer & Explanation

. Common peroneal nerve


Explanation

The posteromedial approach to the tibial plateau utilizes an interval between the medial gastrocnemius and the pes anserinus. The great saphenous vein and saphenous nerve are superficial structures at high risk during the initial dissection.

Question 7605

Topic: 2. Trauma

A 25-year-old multiply injured patient is brought to the trauma bay after a motorcycle collision. He has bilateral femur fractures and a severe closed head injury. Which of the following physiological markers is the most reliable indicator of adequate global tissue perfusion and resuscitation prior to proceeding with Early Total Care (ETC)?

. Urine output greater than 30 mL/hr
. Systolic blood pressure greater than 100 mm Hg
. Serum lactate less than 2.5 mmol/L
. Heart rate less than 100 beats/min
. Glasgow Coma Scale score greater than 8

Correct Answer & Explanation

. Urine output greater than 30 mL/hr


Explanation

Clearance of serum lactate (to < 2.5 mmol/L) and normalization of base deficit are the most reliable indicators of adequate tissue resuscitation. Relying solely on vital signs or urine output can mask compensated shock.

Question 7606

Topic: 2. Trauma

A 32-year-old male sustains a Schatzker VI bicondylar tibial plateau fracture. Twelve hours post-admission, he develops severe, unrelenting leg pain exacerbated by passive stretch of the great toe. Intra-compartmental pressure monitoring reveals a pressure of 45 mm Hg in the anterior compartment, with a diastolic blood pressure of 60 mm Hg. What is the most appropriate next step in management?

. Elevate the leg above the level of the heart
. Administer intravenous mannitol
. Perform a 4-compartment fasciotomy
. Proceed with immediate open reduction and internal fixation
. Apply a long leg bivalved cast

Correct Answer & Explanation

. Elevate the leg above the level of the heart


Explanation

The patient is exhibiting signs of acute compartment syndrome with an absolute pressure of 45 mm Hg and a Delta P (diastolic BP - compartment pressure) of 15 mm Hg. A Delta P less than 30 mm Hg is an absolute indication for emergent 4-compartment fasciotomy.

Question 7607

Topic: 2. Trauma

In the initial management of a hemodynamically unstable polytrauma patient with an open-book pelvic ring injury (APC III), a pelvic binder is applied. To achieve optimal mechanical closure of the pelvic volume, the binder should be centered over which of the following anatomic landmarks?

. Anterior superior iliac spines
. Greater trochanters
. Iliac crests
. Pubic symphysis
. Sacral promontory

Correct Answer & Explanation

. Anterior superior iliac spines


Explanation

Pelvic binders must be centered over the greater trochanters to effectively close the pelvic ring and reduce pelvic volume. Placement over the iliac crests or ASIS is less effective and can paradoxically open the true pelvis further.

Question 7608

Topic: 2. Trauma

A 45-year-old male presents with a severely displaced bicondylar tibial plateau fracture and massive soft tissue swelling with fracture blisters over the anterolateral and medial aspects of the proximal leg. What is the most appropriate initial management of this fracture?

. Immediate dual plating through a single anterior incision
. Immediate dual plating through separate anterolateral and posteromedial incisions
. Spanning external fixation across the knee joint
. Intramedullary nailing
. Skeletal traction via a distal femur pin

Correct Answer & Explanation

. Immediate dual plating through a single anterior incision


Explanation

In the presence of severely compromised soft tissue envelopes (massive swelling, fracture blisters), temporary spanning external fixation is indicated. This stabilizes the fracture while allowing the soft tissues to recover, preventing devastating wound complications from early open surgery.

Question 7609

Topic: 2. Trauma

A 22-year-old male sustains closed bilateral femur fractures in an ATV accident. On post-admission day 2, he develops acute hypoxia, a petechial rash over his axillae, and confusion. Which of the following interventions is the most effective definitive method to prevent the development of this syndrome?

. Prophylactic administration of high-dose corticosteroids
. Placement of an inferior vena cava filter
. Early operative stabilization of the long bone fractures
. Prophylactic administration of low molecular weight heparin
. Continuous positive airway pressure (CPAP) ventilation

Correct Answer & Explanation

. Prophylactic administration of high-dose corticosteroids


Explanation

The patient has Fat Embolism Syndrome, characterized by the classic triad of hypoxemia, neurological abnormalities, and petechial rash. Early operative stabilization (within 24 hours) of long bone fractures is the most effective method for decreasing the incidence of this syndrome.

Question 7610

Topic: 2. Trauma

A 42-year-old female sustains a split-depression lateral tibial plateau fracture (Schatzker type II). During surgical fixation, a submeniscal arthrotomy is performed. Which of the following intra-articular injuries is most frequently encountered with this specific fracture pattern?

. Medial meniscus tear
. Lateral meniscus tear
. Anterior cruciate ligament tear
. Posterior cruciate ligament tear
. Osteochondral defect of the medial femoral condyle

Correct Answer & Explanation

. Medial meniscus tear


Explanation

Lateral meniscal tears are the most common associated intra-articular injuries in Schatzker type II (split-depression) tibial plateau fractures, occurring in up to 50% of cases. The meniscus often becomes incarcerated in the fracture site.

Question 7611

Topic: 2. Trauma

A polytrauma patient with multiple long-bone fractures, pulmonary contusions, and a severe head injury is initially managed with damage control orthopedics (DCO). According to the classic "two-hit" model of systemic inflammation, definitive fracture fixation should ideally be performed during which window to minimize the risk of ARDS and multiple organ failure?

. Within the first 24 hours
. Between days 2 and 4
. Between days 5 and 10
. Between days 11 and 14
. After 3 weeks

Correct Answer & Explanation

. Within the first 24 hours


Explanation

The optimal "window of opportunity" for definitive surgery in polytrauma patients managed with DCO is typically between days 5 and 10. Surgery between days 2 and 4 coincides with the peak systemic inflammatory response syndrome (SIRS) and increases the risk of ARDS as a "second hit."

Question 7612

Topic: 2. Trauma

A 25-year-old male is brought to the emergency department after a high-speed motor vehicle collision. He has a severe traumatic brain injury, multiple rib fractures, and a comminuted midshaft femur fracture. Which of the following systemic markers best indicates that the patient has been adequately resuscitated and is a suitable candidate for early total care?

. Serum lactate < 2.0 mmol/L
. Systolic blood pressure > 90 mmHg
. Heart rate < 100 bpm
. Urine output > 0.5 mL/kg/hr
. Arterial pH > 7.35

Correct Answer & Explanation

. Serum lactate < 2.0 mmol/L


Explanation

Serum lactate and base deficit are the most reliable indicators of systemic tissue perfusion and adequate resuscitation in polytrauma. Normalization of lactate (< 2.0 mmol/L) suggests the patient is clear of the systemic inflammatory danger zone and can tolerate definitive fixation.

Question 7613

Topic: 2. Trauma

A 55-year-old woman undergoes volar locked plating for a comminuted intra-articular distal radius fracture. At 6-month follow-up, she is unable to actively flex the interphalangeal joint of her thumb. What is the most likely cause of this complication?

. Iatrogenic injury to the anterior interosseous nerve
. Rupture of the extensor pollicis longus tendon
. Prominence of the plate distal to the watershed line
. Unrecognized compartment syndrome
. Malunion causing a functional block

Correct Answer & Explanation

. Iatrogenic injury to the anterior interosseous nerve


Explanation

Placement of a volar plate distal to the watershed line risks impingement and subsequent attrition rupture of the flexor pollicis longus (FPL) tendon. The watershed line marks the distal margin of the pronator quadratus, beyond which the tendons lie directly on the bone.

Question 7614

Topic: Lower Extremity Trauma

A 40-year-old man sustains a bicondylar tibial plateau fracture (Schatzker VI) with a displaced posteromedial coronal split fragment. Standard anterolateral plating alone is planned. What is the most likely consequence of failing to specifically address the posteromedial fragment?

. Varus collapse of the knee
. Valgus collapse of the knee
. Anterior subluxation of the tibia
. Peroneal nerve palsy
. Rupture of the medial collateral ligament

Correct Answer & Explanation

. Varus collapse of the knee


Explanation

The posteromedial fragment involves the medial articular surface and supports the medial femoral condyle. Failure to anatomically buttress this fragment typically leads to varus collapse and posterior subluxation of the tibia.

Question 7615

Topic: 2. Trauma

A hypotensive 30-year-old polytrauma patient presents with an anteroposterior compression (APC) type III pelvic ring injury. To effectively reduce the pelvic volume and control hemorrhage, a pelvic binder should be centered over which of the following anatomic landmarks?

. Iliac crests
. Anterior superior iliac spines
. Greater trochanters
. Pubic symphysis
. Sacral promontory

Correct Answer & Explanation

. Iliac crests


Explanation

Pelvic binders must be centered directly over the greater trochanters to effectively reduce the pelvic ring volume and stabilize the symphysis pubis. Placement over the iliac crests is less effective and may paradoxically open the pelvis in certain fracture patterns.

Question 7616

Topic: 2. Trauma

A 35-year-old man undergoes staged management of a high-energy Schatzker VI tibial plateau fracture. He is initially placed in a knee-spanning external fixator. Within 12 hours, he develops severe, unrelenting leg pain exacerbated by passive stretch of the hallux. What is the next most appropriate step in management?

. Loosen the external fixator pins
. Perform immediate four-compartment fasciotomies of the leg
. Administer intravenous antibiotics and re-evaluate
. Obtain urgent CT angiography of the lower extremity
. Elevate the leg and apply ice

Correct Answer & Explanation

. Loosen the external fixator pins


Explanation

Severe pain out of proportion to the injury and exacerbated by passive stretch is the hallmark of acute compartment syndrome. Immediate four-compartment fasciotomies are required to prevent irreversible ischemic necrosis.

Question 7617

Topic: 2. Trauma

According to the principles of Damage Control Orthopedics (DCO), which of the following clinical scenarios represents a borderline patient where temporary external fixation of a femoral shaft fracture is favored over early intramedullary nailing?

. Isolated closed femur fracture with a normal chest radiograph
. Multiple extremity fractures with an ISS of 16
. Femur fracture with bilateral pulmonary contusions and initial lactate of 3.5 mmol/L
. Open tibia fracture with a stable pelvis
. Femur fracture in a 20-year-old with a GCS of 15

Correct Answer & Explanation

. Isolated closed femur fracture with a normal chest radiograph


Explanation

Bilateral pulmonary contusions and elevated initial lactate indicate a high-risk borderline polytrauma patient. Early total care (e.g., IM nailing) in this setting risks a fatal second hit such as ARDS, making DCO the safer strategy.

Question 7618

Topic: 2. Trauma

A 45-year-old man sustains a Schatzker II (split-depression) fracture of the lateral tibial plateau. During operative fixation, a peripheral tear of the lateral meniscus is identified. What is the most appropriate management of the meniscus?

. Total lateral meniscectomy
. Partial lateral meniscectomy
. Submeniscal arthrotomy and meniscus repair after fracture fixation
. Leave the tear in situ without repair
. Meniscal allograft transplantation

Correct Answer & Explanation

. Total lateral meniscectomy


Explanation

The lateral meniscus is torn in a significant percentage of Schatzker II fractures, most often peripherally. The meniscus must be elevated to visualize and reduce the joint surface, followed by secure repair to restore hoop stresses and protect the articular cartilage.

Question 7619

Topic: 2. Trauma

A 78-year-old polytrauma patient with bilateral lower extremity fractures sustains a highly comminuted, intra-articular fracture of the distal radius extending into the metadiaphysis. The patient requires the use of the upper extremities for weight-bearing transfers. What is the most appropriate fixation strategy for the wrist?

. Volar locking plate
. Dorsal spanning plate
. External fixation with K-wire augmentation
. Fragment-specific fixation
. Closed reduction and short arm cast

Correct Answer & Explanation

. Volar locking plate


Explanation

A dorsal spanning plate provides excellent load-sharing stability in highly comminuted fractures or in patients requiring early weight-bearing through the upper extremities. It bridges the radiocarpal joint, allowing early transfer mobility while protecting the articular reduction.

Question 7620

Topic: 2. Trauma

A 45-year-old male sustains a high-energy Schatzker VI bicondylar tibial plateau fracture. Thirty-six hours after undergoing open reduction and internal fixation with dual plating, he develops severe, unrelenting leg pain that is exacerbated by passive plantar flexion of the toes. Examination reveals decreased sensation in the first dorsal web space. Which of the following compartments is most likely affected, and which nerve is at greatest risk?

. Anterior compartment; deep peroneal nerve
. Lateral compartment; superficial peroneal nerve
. Deep posterior compartment; tibial nerve
. Superficial posterior compartment; sural nerve
. Anterior compartment; saphenous nerve

Correct Answer & Explanation

. Anterior compartment; deep peroneal nerve


Explanation

High-energy tibial plateau fractures carry a significant risk for compartment syndrome, most commonly affecting the anterior compartment. The deep peroneal nerve courses through the anterior compartment, and ischemia leads to weakness in toe extension and paresthesias in the first dorsal web space.