Menu

2. Trauma MCQs

Practice Set 610 of 640

This practice set contains high-yield board review questions covering key concepts in 2. Trauma. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 12181

Topic: 2. Trauma

The Sanders classification is utilized for preoperative planning of intra-articular calcaneus fractures. Which imaging modality and anatomical plane is the basis for this classification system?

. Axial CT scan parallel to the plantar fascia
. Sagittal CT scan through the anterior process
. Coronal CT scan through the widest portion of the posterior facet
. Radiographic Harris axial view
. Radiographic lateral view assessing Bohler's angle

Correct Answer & Explanation

. Coronal CT scan through the widest portion of the posterior facet

Explanation

The Sanders classification relies on coronal CT imaging at the widest point of the posterior facet of the calcaneus, categorizing fractures based on the number and location of articular fracture lines.

Question 12182

Topic: 2. Trauma

A 20-year-old track athlete presents with insidious onset, vague midfoot pain. MRI confirms a stress fracture of the tarsal navicular. Which region of the navicular is most susceptible to this injury due to its watershed blood supply?

. Plantar cortex
. Central third
. Medial tuberosity
. Dorsal-lateral articulation
. Plantar-medial pole

Correct Answer & Explanation

. Central third

Explanation

The central third of the navicular is a relative watershed area, receiving precarious blood supply from the medial and lateral capsular vessels. This lack of vascularity makes it highly susceptible to stress fractures and nonunion.

Question 12183

Topic: 2. Trauma

A 22-year-old elite collegiate basketball player sustains a fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal base (Zone 2). Given his desire for a rapid and reliable return to sport, what is the gold standard treatment?

. Non-weight-bearing in a short leg cast for 8 weeks
. Weight-bearing as tolerated in a stiff-soled shoe
. Open reduction and internal fixation with a lateral plate
. Intramedullary screw fixation
. Excision of the proximal fragment and peroneus brevis advancement

Correct Answer & Explanation

. Intramedullary screw fixation

Explanation

Zone 2 fractures (Jones fractures) have a high risk of delayed union or nonunion due to watershed vascularity. In high-performance athletes, intramedullary screw fixation is the gold standard to decrease nonunion rates and accelerate return to play.

Question 12184

Topic: 2. Trauma

A 19-year-old elite collegiate basketball player sustains an acute, non-displaced fracture of the fifth metatarsal at the metaphyseal-diaphyseal junction (Zone 2). To minimize the risk of nonunion and expedite return to play, what is the most appropriate management?

. Short leg walking cast for 6 weeks
. Non-weight-bearing short leg cast for 8 weeks
. Intramedullary screw fixation
. Plating of the fifth metatarsal
. Excision of the proximal fragment with peroneus brevis advancement

Correct Answer & Explanation

. Intramedullary screw fixation

Explanation

Zone 2 fifth metatarsal fractures (Jones fractures) occur in a vascular watershed area and have a high rate of nonunion. In elite athletes, early intramedullary screw fixation is recommended to significantly decrease nonunion rates and allow for a faster return to sport compared to non-operative management.

Question 12185

Topic: 2. Trauma

A 28-year-old male presents with severe left leg pain following a closed tibial shaft fracture sustained in a motor vehicle collision. The pain is not relieved by intravenous opioids. On examination, the leg is tense and swollen. Pulses are palpable and capillary refill is less than 2 seconds. Which of the following is the most reliable early clinical indicator of the suspected diagnosis?

. Loss of palpable pedal pulses
. Decreased capillary refill
. Pain with passive stretch of the toes
. Pallor of the distal extremity
. Motor paralysis of the deep posterior compartment

Correct Answer & Explanation

. Pain with passive stretch of the toes

Explanation

Pain out of proportion to the injury and exacerbated by passive stretch of the involved muscles is the most reliable early clinical sign of acute compartment syndrome. Pulselessness, pallor, and paralysis are late, often irreversible signs.

Question 12186

Topic: 2. Trauma
A 35-year-old male arrives in hemorrhagic shock following a motorcycle crash. Primary survey reveals an unstable anteroposterior compression type III (APC-III) pelvic ring injury. A pelvic binder is applied, and the FAST exam is negative. Despite 2 units of uncrossmatched blood, his blood pressure remains 70/40 mmHg. According to ATLS protocols, what is the next most appropriate intervention?
. Immediate CT scan of the abdomen and pelvis
. Retroperitoneal pelvic packing or angiography/embolization
. Exploratory laparotomy with splenic packing
. Open reduction and internal fixation of the pubic symphysis
. Application of bilateral lower extremity traction

Correct Answer & Explanation

. Retroperitoneal pelvic packing or angiography/embolization

Explanation

In a hemodynamically unstable patient with a mechanically stabilized pelvic fracture and no other identified sources of bleeding (negative FAST), the bleeding is presumed to be retroperitoneal. Pre-peritoneal pelvic packing or angioembolization is indicated to control venous and arterial hemorrhage.

Question 12187

Topic: 2. Trauma

A 24-year-old male falls onto an outstretched hand and sustains a displaced fracture through the proximal pole of the scaphoid. This specific fracture pattern has a high risk of nonunion and avascular necrosis because the primary blood supply enters the scaphoid at which location?

. The volar tubercle via the superficial palmar arch
. The proximal articular surface via intracapsular vessels
. The dorsal ridge via branches of the radial artery
. The waist via branches of the ulnar artery
. The distal pole via the anterior interosseous artery

Correct Answer & Explanation

. The dorsal ridge via branches of the radial artery

Explanation

The major blood supply to the scaphoid enters distally along the dorsal ridge via branches of the radial artery, perfusing the bone in a retrograde fashion. Fractures at the proximal pole disrupt this retrograde supply, leading to a high rate of avascular necrosis.

Question 12188

Topic: 2. Trauma

A 35-year-old male sustains a closed spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture). On initial presentation in the emergency department, his radial nerve motor and sensory exams are completely intact. After closed reduction and application of a coaptation splint, he is unable to extend his wrist or fingers. What is the most appropriate next step in management?

. Observation and repeat electromyography (EMG) at 6 weeks
. Immediate surgical exploration of the radial nerve
. Application of a dynamic extension splint and physical therapy
. Removal of the splint and re-manipulation under conscious sedation
. Prescribe oral corticosteroids to reduce nerve edema

Correct Answer & Explanation

. Immediate surgical exploration of the radial nerve

Explanation

A radial nerve palsy that newly develops or worsens immediately after a closed reduction of a humeral shaft fracture strongly suggests iatrogenic nerve entrapment within the fracture site. This is an absolute indication for immediate surgical exploration.

Question 12189

Topic: 2. Trauma
A 25-year-old male sustains a Gustilo-Anderson Type IIIA open tibia fracture. According to established trauma principles, which of the following interventions has been proven to have the greatest impact on reducing the subsequent risk of deep infection?
. Early administration of systemic intravenous antibiotics
. Serial sharp wound debridements every 24 hours
. Application of negative pressure wound therapy (VAC)
. Delayed primary wound closure at 5 days
. Placement of local antibiotic-impregnated cement beads

Correct Answer & Explanation

. Early administration of systemic intravenous antibiotics

Explanation

The early administration of systemic intravenous antibiotics (ideally within 1-3 hours of injury) is the single most important, evidence-based intervention for reducing the infection rate in open fractures.

Question 12190

Topic: 2. Trauma

A 32-year-old man sustains a closed diaphyseal tibia fracture. He reports excruciating leg pain out of proportion to the injury. Which of the following parameters is the most reliable indicator for emergency fasciotomy?

. Absolute compartment pressure greater than 20 mmHg
. Absolute compartment pressure greater than 30 mmHg
. Differential pressure (Diastolic BP minus compartment pressure) less than 30 mmHg
. Differential pressure (Mean arterial pressure minus compartment pressure) less than 40 mmHg
. Loss of distal pulses on Doppler ultrasound

Correct Answer & Explanation

. Differential pressure (Diastolic BP minus compartment pressure) less than 30 mmHg

Explanation

A delta pressure (diastolic blood pressure minus compartment pressure) of less than 30 mmHg is the most reliable threshold for diagnosing acute compartment syndrome and indicating fasciotomy. Absolute pressures are less reliable due to systemic blood pressure variations.

Question 12191

Topic: 2. Trauma
A 45-year-old man is brought to the trauma bay after a motorcycle collision. He is hypotensive and tachycardic. Pelvic radiographs show an anteroposterior compression (APC) type III injury. Where should a pelvic binder be anatomically centered to most effectively reduce pelvic volume?
. Over the iliac crests
. Over the greater trochanters
. Over the anterior superior iliac spines (ASIS)
. Over the mid-thighs
. Directly over the pubic symphysis

Correct Answer & Explanation

. Over the greater trochanters

Explanation

A pelvic binder must be placed at the level of the greater trochanters to effectively close the pelvic ring and reduce pelvic volume. Placement over the iliac crests is incorrect and can paradoxically open the pelvis further in some fracture patterns.

Question 12192

Topic: 2. Trauma
A 28-year-old man sustains a displaced, vertically oriented (Pauwels type III) femoral neck fracture. He undergoes closed reduction and internal fixation with cannulated screws. Which of the following represents the highest risk complication associated with this specific fracture pattern?
. Deep vein thrombosis
. Varus collapse and nonunion
. Infection
. Heterotopic ossification
. Chondrolysis

Correct Answer & Explanation

. Varus collapse and nonunion

Explanation

Pauwels type III fractures are highly vertical, generating significant shear forces rather than compressive forces across the fracture site. This mechanical disadvantage leads to a high rate of varus collapse, hardware failure, and nonunion compared to more horizontal fracture patterns.

Question 12193

Topic: 2. Trauma

A 24-year-old male is evaluated for acute compartment syndrome following a closed tibial shaft fracture. Pathophysiologically, the earliest ischemic change in acute compartment syndrome is initiated by which of the following events?

. Arterial inflow obstruction
. Lymphatic stasis
. Venous outflow obstruction
. Capillary bed occlusion
. Neuromuscular junction blockade

Correct Answer & Explanation

. Venous outflow obstruction

Explanation

The pathophysiology of compartment syndrome begins with an increase in tissue pressure that eventually exceeds venous pressure, leading to venous outflow obstruction. This raises venular and capillary pressure, reducing the arteriovenous (AV) perfusion gradient, which ultimately leads to muscle and nerve ischemia before arterial inflow is compromised.

Question 12194

Topic: 2. Trauma

A 25-year-old male undergoes closed reamed intramedullary nailing for a diaphyseal femoral shaft fracture. Which of the following best describes the primary type of bone healing expected in this scenario?

. Primary intramembranous healing
. Primary osteonal reconstruction via cutting cones
. Secondary healing via callus formation
. Purely endochondral ossification without membranous contribution
. Direct cortical remodeling without any callus phase

Correct Answer & Explanation

. Secondary healing via callus formation

Explanation

Intramedullary nailing provides relative stability to a fracture site, which permits controlled micromotion. This mechanical environment stimulates secondary bone healing, which proceeds through the formation of a soft callus (endochondral ossification) and hard callus, rather than primary (direct) bone healing, which requires absolute stability and rigid compression (e.g., via plating).

Question 12195

Topic: 2. Trauma
A 45-year-old farmer sustains a Gustilo-Anderson Type IIIA open tibial shaft fracture highly contaminated with soil. According to current trauma guidelines, what is the most appropriate initial intravenous antibiotic regimen?
. Cefazolin alone
. Cefazolin and gentamicin
. Cefazolin, gentamicin, and penicillin
. Piperacillin-Tazobactam alone
. Clindamycin and ciprofloxacin

Correct Answer & Explanation

. Cefazolin, gentamicin, and penicillin

Explanation

For Type III open fractures, a first-generation cephalosporin and an aminoglycoside are standard to cover gram-positive and gram-negative organisms. Penicillin is added for agricultural or highly contaminated injuries to cover anaerobes, specifically Clostridium.

Question 12196

Topic: 2. Trauma

A 22-year-old male sustains a proximal pole scaphoid fracture. Which anatomic characteristic of the scaphoid's blood supply places him at high risk for avascular necrosis?

. Volar proximal entry of intraosseous vessels
. Direct arterial perforators from the radial artery to the proximal pole
. Dorsal distal entry with retrograde intraosseous flow
. Volar distal entry with robust collateral flow
. Lack of any intraosseous blood supply

Correct Answer & Explanation

. Dorsal distal entry with retrograde intraosseous flow

Explanation

The primary blood supply to the scaphoid enters dorsally at the distal ridge and flows retrograde to the proximal pole. Fractures at the proximal pole disrupt this retrograde supply, leading to a high rate of avascular necrosis and nonunion.

Question 12197

Topic: 2. Trauma
A polytrauma patient arrives hypotensive with a widened symphysis pubis and disrupted posterior sacroiliac ligaments (APC III pelvic ring injury). After initial ABCs, what is the most appropriate first mechanical intervention to control hemorrhage?
. Immediate operative pelvic packing
. Application of a pelvic binder centered over the greater trochanters
. Application of a pelvic binder centered over the iliac crests
. External fixation of the anterior pelvis
. Diagnostic peritoneal lavage

Correct Answer & Explanation

. Application of a pelvic binder centered over the greater trochanters

Explanation

For an unstable, mechanically open pelvic ring injury (APC), reducing pelvic volume is critical to control venous bleeding. A pelvic binder must be applied centered over the greater trochanters to effectively close the pelvic volume.

Question 12198

Topic: 2. Trauma

The primary blood supply to the adult femoral head, which is highly susceptible to disruption in displaced intracapsular femoral neck fractures, arises from branches of which artery?

. Medial femoral circumflex artery
. Lateral femoral circumflex artery
. Artery of the ligamentum teres
. Inferior gluteal artery
. Superior gluteal artery

Correct Answer & Explanation

. Medial femoral circumflex artery

Explanation

The medial femoral circumflex artery (MFCA), specifically its lateral epiphyseal branches, provides the predominant blood supply to the adult femoral head. Disruption leads to a high risk of avascular necrosis in displaced femoral neck fractures.

Question 12199

Topic: 2. Trauma

A 25-year-old polytraumatized, obtunded patient sustains a closed tibial shaft fracture. You suspect acute compartment syndrome. Which of the following pressure measurements provides the most reliable indication for urgent fasciotomy?

. Absolute compartment pressure > 20 mmHg
. Absolute compartment pressure > 30 mmHg
. Diastolic blood pressure minus compartment pressure < 30 mmHg
. Mean arterial pressure minus compartment pressure < 40 mmHg
. Systolic blood pressure minus compartment pressure < 30 mmHg

Correct Answer & Explanation

. Diastolic blood pressure minus compartment pressure < 30 mmHg

Explanation

The Delta P (Diastolic Blood Pressure minus Compartment Pressure) is the most reliable threshold for diagnosing acute compartment syndrome. A Delta P of less than 30 mmHg indicates inadequate tissue perfusion and is a strong indication for fasciotomy.

Question 12200

Topic: Pelvic & Acetabular Trauma
A 45-year-old male is brought to the trauma bay following a motorcycle collision. He is hemodynamically unstable with an anteroposterior compression (APC) type III pelvic ring injury. Following the application of a pelvic binder, what is the primary pathophysiological source of pelvic bleeding in this specific injury pattern?
. Superior gluteal artery
. Internal pudendal artery
. Presacral venous plexus and cancellous bone
. External iliac artery
. Corona mortis

Correct Answer & Explanation

. Presacral venous plexus and cancellous bone

Explanation

Despite the potential for catastrophic arterial bleeding, approximately 80-90% of hemorrhage in severe pelvic ring injuries originates from the presacral venous plexus and bleeding cancellous bone surfaces. A pelvic binder helps reduce pelvic volume to tamponade this venous and osseous bleeding.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page