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2. Trauma MCQs

Practice Set 35 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 681

Topic: Lower Extremity Trauma

During the radiographic evaluation of an acute ankle injury, which of the following findings on standard plain radiographs is considered the most reliable indicator of a distal tibiofibular syndesmotic disruption?

. Tibiofibular clear space greater than 6 mm on both AP and mortise views
. Tibiofibular overlap greater than 10 mm on the AP view
. Medial clear space of 2 mm on the mortise view
. Talar tilt angle of 5 degrees
. Complete obliteration of the lateral gutter

Correct Answer & Explanation

. Tibiofibular clear space greater than 6 mm on both AP and mortise views

Explanation

A tibiofibular clear space greater than 5-6 mm on either the AP or mortise radiograph is the most reliable radiographic indicator of syndesmotic injury. Normal tibiofibular overlap should be >1 mm on the mortise view and >6 mm on the AP view.

Question 682

Topic: 2. Trauma

A patient sustains a crush injury when heavy farm equipment rolls over his foot. He presents to the emergency department 4 hours later with pain and swelling in the foot. Radiographic examination is normal. You examine him for a compartment syndrome. The intracompartmental pressure in the interosseous compartment is 20 mm Hg. The next phase of management may include all of the following except:

. Examination under anesthesia followed by fasciotomy
. Application of an intermittent foot pump device
. Observation and repeat compartment pressure monitoring
. Application of a bulky soft tissue dressing with a posterior plaster splint
. Admission to hospital for elevation and management of pain with narcotics

Correct Answer & Explanation

. Application of an intermittent foot pump device

Explanation

Fasciotomy of the foot is not indicated when pressures are less than 20 mm Hg. All of the alternatives are reasonable forms of treatment including application of an intermittent foot pump device that has been demonstrated to decrease compartment pressures of the foot. If pressures were more than 30 mm Hg, then a fasciotomy may be indicated.

Question 683

Topic: 2. Trauma

A 40-year-old man sustains a high-energy varus directed force to his knee resulting in a medial tibial plateau fracture.

Which of the following associated neurovascular injuries is most frequently seen with this specific high-energy fracture pattern compared to lateral plateau injuries?

. Superficial peroneal nerve palsy
. Deep peroneal nerve palsy
. Popliteal artery injury
. Anterior tibial artery injury
. Saphenous nerve injury

Correct Answer & Explanation

. Popliteal artery injury

Explanation

Schatzker IV (medial tibial plateau) fractures typically result from high-energy trauma and represent knee dislocation equivalents. They have a significantly higher association with popliteal artery injuries and peroneal nerve palsies than lateral plateau fractures.

Question 684

Topic: Pelvic & Acetabular Trauma

A 28-year-old motorcyclist is brought to the ED after a collision. Pelvic radiographs show a symphyseal diastasis of 3.5 cm and widening of the anterior sacroiliac joints bilaterally.

Which ligamentous structures are completely ruptured in this injury?

. Sacrotuberous, sacrospinous, and anterior sacroiliac ligaments
. Sacrotuberous and posterior sacroiliac ligaments
. Anterior and posterior sacroiliac ligaments
. Iliolumbar and anterior sacroiliac ligaments
. Sacrotuberous, sacrospinous, anterior, and posterior sacroiliac ligaments

Correct Answer & Explanation

. Sacrotuberous, sacrospinous, and anterior sacroiliac ligaments

Explanation

In an Anteroposterior Compression (APC) Type II injury, pubic symphysis diastasis exceeds 2.5 cm. There is rupture of the anterior SI, sacrotuberous, and sacrospinous ligaments, while the posterior SI ligaments remain intact providing vertical stability.

Question 685

Topic: 2. Trauma

A 30-year-old man sustains a closed tibial shaft fracture. Twelve hours later, he complains of severe leg pain out of proportion to the injury. Which of the following physical examination findings is the most sensitive early clinical indicator of acute compartment syndrome?

. Loss of distal pulses
. Capillary refill time greater than 3 seconds
. Pallor of the foot
. Pain with passive stretch of the toes
. Paralysis of the extensor hallucis longus

Correct Answer & Explanation

. Pain with passive stretch of the toes

Explanation

Pain with passive stretch of the muscles traversing the involved compartment is considered the most sensitive and reliable early clinical sign of acute compartment syndrome. Pulselessness and paralysis are late, often irreversible signs.

Question 686

Topic: 2. Trauma

In evaluating an ankle fracture for syndesmotic instability, which radiographic parameter on a standard AP or mortise view is most indicative of a syndesmotic injury?

. Tibiofibular overlap greater than 1 mm on the mortise view
. Tibiofibular clear space greater than 6 mm on the AP or mortise view
. Medial clear space greater than 4 mm on the mortise view
. Talar tilt greater than 5 degrees
. Calcaneal pitch less than 15 degrees

Correct Answer & Explanation

. Tibiofibular clear space greater than 6 mm on the AP or mortise view

Explanation

A tibiofibular clear space greater than 6 mm on the AP or mortise radiograph is the most reliable parameter indicating diastasis and syndesmotic ligament injury. It is measured 1 cm proximal to the plafond.

Question 687

Topic: Lower Extremity Trauma

A 45-year-old man presents with a Schatzker type II tibial plateau fracture. Which of the following surgical approaches is most commonly utilized for open reduction and internal fixation of this injury?

. Posteromedial approach
. Anterolateral approach
. Direct medial approach
. Posterior approach

Correct Answer & Explanation

. Anterolateral approach

Explanation

A Schatzker type II fracture is a split-depression of the lateral tibial plateau. The anterolateral approach provides optimal visualization for elevating the depressed articular segment and applying a lateral buttress plate.

Question 688

Topic: 2. Trauma

A 28-year-old male sustains a closed tibia fracture. Hours later, he develops severe pain out of proportion to the injury. Intracompartmental pressure testing is performed. Which measurement is generally considered the threshold indicating the need for emergent fasciotomy?

. Absolute compartment pressure > 15 mmHg
. Delta pressure (Diastolic BP minus compartment pressure) < 30 mmHg
. Delta pressure (Diastolic BP minus compartment pressure) > 45 mmHg
. Absolute compartment pressure > 20 mmHg

Correct Answer & Explanation

. Delta pressure (Diastolic BP minus compartment pressure) < 30 mmHg

Explanation

A delta pressure (diastolic blood pressure minus compartment pressure) of less than 30 mmHg is highly sensitive for compartment syndrome. This value is widely accepted as an absolute indication for emergent fasciotomy.

Question 689

Topic: 2. Trauma
A 30-year-old motorcyclist sustains an anteroposterior compression (APC) type III pelvic ring injury. What is the most common primary source of life-threatening hemorrhage in this specific injury pattern?
. Venous plexus and cancellous bone
. Superior gluteal artery
. Obturator artery
. External iliac artery

Correct Answer & Explanation

. Venous plexus and cancellous bone

Explanation

Although arterial injuries can occur, the vast majority of retroperitoneal bleeding in severe pelvic fractures originates from the disrupted presacral venous plexus and exposed cancellous bone surfaces.

Question 690

Topic: 2. Trauma

A patient presents for treatment of painful toes 1 year after open reduction and internal fixation of a calcaneus fracture. He notes difficulty with shoe wear and pain on ambulation. On examination, there are fixed claw toe deformities of the second, third, and fourth toes that are painful. The most likely cause of the toe deformities is:

. Entrapment of the medial plantar nerve
. Flexor digitorum longus stenosis associated with entrapment in the deep muscle layer of the foot
. Tethering of the flexor hallucis longus under the sustentaculum tali
. Unrecognized injury to the forefoot at the time of the original calcaneus fracture
. Unrecognized compartment syndrome of the foot

Correct Answer & Explanation

. Unrecognized compartment syndrome of the foot

Explanation

Claw toe deformities after calcaneus fracture occur as a result of untreated compartment syndrome. C ompartment syndrome occurs as a result of intrinsic muscle atrophy or fibrosis of the short flexor muscles followed by fixed toe deformity.

Question 691

Topic: 2. Trauma

Which of the following statements regarding a fracture of the junction of the proximal metaphyseal and diaphyseal portion of the fifth metatarsal is false:

. A fracture of the junction of the proximal metaphyseal and diaphyseal portion of the fifth metatarsal is the least likely of all fifth metatarsal fractures to heal.
. Fractures treated nonoperatively heal from medial to lateral on serial radiographs.
. The mechanism of injury is forced abduction.
. Radiographic evidence of union lags behind clinical healing examination.
. Up to one-third of patients treated with casting may refracture in long- term follow-up.

Correct Answer & Explanation

. A fracture of the junction of the proximal metaphyseal and diaphyseal portion of the fifth metatarsal is the least likely of all fifth metatarsal fractures to heal.

Explanation

The fracture of the junction of the proximal metaphyseal and diaphyseal portion of the fifth metatarsal, otherwise known as the Jones fracture, causes complications with bone healing. The fracture is caused by a plantarflexion inversion twist of the foot and ankle and needs prompt treatment because nonunion rates are high with this type of fracture.

Question 692

Topic: 2. Trauma

A 45-year-old female presents after a high-speed motor vehicle collision with a Schatzker IV tibial plateau fracture. Which of the following neurovascular structures is at the highest risk of injury in this specific fracture pattern?

. Peroneal nerve
. Popliteal artery
. Anterior tibial artery
. Saphenous nerve
. Sural nerve

Correct Answer & Explanation

. Popliteal artery

Explanation

A Schatzker IV fracture involves the medial tibial plateau and is typically the result of high-energy trauma. Due to the high energy and valgus deforming forces, there is a significantly increased risk of popliteal artery injury and compartment syndrome.

Question 693

Topic: 2. Trauma

A 22-year-old female soccer player sustains a non-contact pivoting injury to her knee, hearing a loud "pop." Radiographs show an elliptic bone fragment avulsed from the lateral tibial plateau (Segond fracture). This fracture represents an avulsion of which structure?

. Medial collateral ligament
. Anterolateral ligament
. Iliotibial band
. Biceps femoris tendon
. Popliteofibular ligament

Correct Answer & Explanation

. Anterolateral ligament

Explanation

A Segond fracture is a pathognomonic radiographic sign for an anterior cruciate ligament (ACL) tear. It represents an avulsion of the anterolateral ligament (ALL) and lateral capsular structures from the proximal anterolateral tibia.

Question 694

Topic: 2. Trauma
A 28-year-old male sustains an open midshaft tibia fracture. There is a 12 cm laceration with severe periosteal stripping, and the wound cannot be closed primarily, requiring a rotational muscle flap for coverage. What is the correct Gustilo-Anderson classification?
. Type IIIA
. Type IIIB
. Type IIIC
. Type II
. Type I

Correct Answer & Explanation

. Type IIIB

Explanation

Gustilo-Anderson Type IIIB fractures involve extensive soft-tissue injury with periosteal stripping and bone exposure, requiring a local or free flap for coverage. Type IIIC would involve an arterial injury requiring repair.

Question 695

Topic: Pelvic & Acetabular Trauma

A 42-year-old man presents in hemorrhagic shock following a severe crush injury to his pelvis. Pelvic radiograph shows a 4 cm pubic symphysis diastasis with disruption of the sacroiliac joints. Following 1L of crystalloid fluid, his blood pressure remains 75/40 mmHg. The most appropriate immediate next step in management is:

. Immediate operative open reduction and internal fixation
. Angiography for embolization
. Application of a circumferential pelvic binder
. Retrograde urethrogram
. Intravenous administration of high-dose vasopressors

Correct Answer & Explanation

. Application of a circumferential pelvic binder

Explanation

The initial management of a mechanically unstable pelvic ring injury in a hemodynamically unstable patient is closing the pelvic volume with a binder or sheet. This facilitates tamponade of venous bleeding and bony stabilization prior to potential angiography or surgery.

Question 696

Topic: 2. Trauma

A 31-year-old man falls from a height and sustains a displaced fracture of the talar neck with subluxation of the subtalar joint, but the tibiotalar joint remains congruous.

According to the Hawkins classification, what is the expected rate of avascular necrosis (AVN) of the talar body for this injury?

. 0% to 10%
. 20% to 50%
. 70% to 100%
. Always 100%
. AVN does not occur in this specific pattern

Correct Answer & Explanation

. 20% to 50%

Explanation

This describes a Hawkins Type II talar neck fracture, involving subtalar subluxation or dislocation with a normal tibiotalar joint. The reported incidence of AVN for Type II fractures ranges from 20% to 50%.

Question 697

Topic: 2. Trauma

A 35-year-old male presents to the emergency department after a high-speed motor vehicle collision. Radiographs demonstrate a butterfly fragment of the pubic rami and widening of the sacroiliac joint. During the secondary survey, blood is noted at the urethral meatus. What is the most appropriate next step in management?

. Retrograde urethrogram
. Foley catheter placement
. Suprapubic cystostomy
. CT cystogram
. Diagnostic peritoneal lavage

Correct Answer & Explanation

. Retrograde urethrogram

Explanation

Blood at the urethral meatus is a classic sign of a possible urethral tear in the setting of pelvic trauma. A retrograde urethrogram must be performed prior to any attempt at Foley catheter placement to avoid converting a partial tear into a complete transection.

Question 698

Topic: 2. Trauma

A 28-year-old man sustains a closed tibial shaft fracture during a football tackle. Twelve hours post-injury, he develops excruciating leg pain that is out of proportion to the injury and unrelieved by intravenous opioids. His pain is exacerbated by passive stretch of the hallux. Pulses are palpable. What is the definitive treatment?

. Elevate the extremity above the level of the heart
. Administration of intravenous corticosteroids
. Immediate four-compartment fasciotomy
. Closed reduction and application of a long-leg cast
. Observation with serial neurovascular checks

Correct Answer & Explanation

. Immediate four-compartment fasciotomy

Explanation

Pain out of proportion to the injury and pain with passive stretch are the earliest and most reliable clinical indicators of acute compartment syndrome. The definitive treatment is emergent surgical decompression via a four-compartment fasciotomy; palpable pulses do not rule out the condition.

Question 699

Topic: 2. Trauma

The most reliable clinical finding of an acute compartment syndrome of the foot is:

. Absent pulses
. Diminished sensation along the plantar medial foot
. Diminished sensation along the dorsal foot surface
. Marked tense foot swelling and pain
. Pain upon passive dorsiflexion of the toes

Correct Answer & Explanation

. Pain upon passive dorsiflexion of the toes

Explanation

The most reliable clinical finding of an acute compartment syndrome of the foot is pain upon passive dorsiflexion of the toes. Decreased sensation does not occur commonly and is a late finding, along with changes in perfusion to the foot.

Question 700

Topic: 2. Trauma

When performing fasciotomy of the foot for acute compartment syndrome, the muscle specifically decompressed through medial fasciotomy is:

. Flexor hallucis brevis
. Quadratus plantae
. Extensor hallucis brevis
. Abductor digiti minimi
. First dorsal interosseous

Correct Answer & Explanation

. Flexor hallucis brevis

Explanation

Knowledge of the anatomy and pathophysiology of compartment syndrome of the foot is important to plan adequate and correct treatment. The exact number of compartments is not as relevant as the location and ability to decompress the compartment through fasciotomy. The medial compartment contains the abductor hallucis and the flexor hallucis brevis muscles. The quadrates plantae is more posteriorly located and considered to be in a separate calcaneal compartment.

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