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2. Trauma MCQs

Practice Set 347 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 6921

Topic: 2. Trauma

A 22-year-old woman involved in a high-speed motor vehicle collision as a rear-seat passenger wearing a lap belt presents with severe back pain. Imaging shows an L2 fracture with a horizontal split through the spinous process, pedicles, and vertebral body. What associated injury must be most highly suspected?

. Aortic dissection
. Renal artery thrombosis
. Intra-abdominal hollow viscus injury
. Diaphragmatic rupture
. Pelvic ring disruption

Correct Answer & Explanation

. Intra-abdominal hollow viscus injury

Explanation

This describes a bony Chance fracture (flexion-distraction injury) classically associated with lap seatbelts. These injuries have a very high association (up to 50%) with intra-abdominal hollow viscus injuries, particularly bowel perforations.

Question 6922

Topic: 2. Trauma
A 35-year-old man fell 30 feet from a roof. Pelvic radiographs and CT demonstrate a transverse sacral fracture through the S1/S2 neural foramina connecting bilateral vertical sacral fractures. He has saddle anesthesia and sphincter dysfunction. This injury pattern represents:
. Denis Zone I sacral fracture
. Denis Zone II sacral fracture
. Anterior-posterior compression type III pelvic injury
. Spinopelvic dissociation (U-type sacral fracture)
. Lateral compression type I pelvic injury

Correct Answer & Explanation

. Spinopelvic dissociation (U-type sacral fracture)

Explanation

A transverse fracture line connecting bilateral vertical sacral fractures forms a U-type or H-type pattern, characteristic of spinopelvic dissociation. This highly unstable injury disconnects the spine from the pelvis and frequently causes profound neurologic deficits.

Question 6923

Topic: 2. Trauma

A 72-year-old man sustains a Type II odontoid fracture after a low-speed motor vehicle collision. He is considered for nonoperative management. Which of the following factors most significantly increases his risk of nonunion if treated with a cervical collar?

. Initial fracture displacement greater than 5 mm
. Age less than 65 years
. Anterior angulation of 5 degrees
. Application of a halo vest within 24 hours
. A concomitant non-displaced C1 anterior arch fracture

Correct Answer & Explanation

. Initial fracture displacement greater than 5 mm

Explanation

Risk factors for nonunion in Type II odontoid fractures include age > 65 years, initial displacement > 5 mm, posterior displacement, and a delay in diagnosis. Displacement > 5 mm carries a high rate of nonunion when treated conservatively.

Question 6924

Topic: 2. Trauma

An 80-year-old man sustains a Type II odontoid fracture after a ground-level fall. He is neurologically intact. Which of the following radiographic findings is the strongest predictor of nonunion if treated conservatively with a rigid cervical collar?

. Anterior displacement of 2 mm
. Posterior displacement of 3 mm
. Fracture displacement > 5 mm
. Angulation of 5 degrees
. Presence of a comminuted C1 arch fracture

Correct Answer & Explanation

. Fracture displacement > 5 mm

Explanation

Initial fracture displacement greater than 5 mm is a classic risk factor for nonunion in Type II odontoid fractures. Other risk factors include age > 50 years, posterior displacement, and delay in treatment.

Question 6925

Topic: 2. Trauma

A 78-year-old man trips on a rug and sustains an isolated Type II odontoid fracture. He is neurologically intact. You are discussing nonoperative management in a hard cervical collar versus surgical stabilization. Which of the following injury characteristics is most strongly associated with an increased risk of nonunion if treated nonoperatively?

. Anterior displacement of 2 mm
. Initial fracture displacement greater than 5 mm
. Concomitant fracture of the C1 anterior arch
. Fracture angulation of 5 degrees
. Treatment initiated within 24 hours of injury

Correct Answer & Explanation

. Initial fracture displacement greater than 5 mm

Explanation

Risk factors for nonunion in Type II odontoid fractures include initial displacement greater than 5 mm, angulation greater than 10 degrees, advanced age (typically > 65 years), and a delay in diagnosis.

Question 6926

Topic: 2. Trauma

Figure 12 shows the radiograph of an 80-year-old woman who has had an 8-month history of back pain after a fall. What is the most likely diagnosis based on the radiographic findings at the fractured vertebrae?

. A healing osteoporotic compression fracture
. A pathologic fracture that is the result of an underlying neoplasm
. Nonunion of the fracture with osteonecrosis
. Vertebral osteomyelitis
. Degeneration of the adjacent intervertebral disk

Correct Answer & Explanation

. Nonunion of the fracture with osteonecrosis

Explanation

An intravertebral vacuum cleft suggests nonunion of the vertebral fracture with osteonecrosis and is not seen in routine healing fractures. MRI characteristically shows a high T2 signal in the cleft. The cleft is not indicative of an infectious or neoplastic lesion. A vacuum disk phenomenon is associated with end-stage degenerative disk disease, but those findings are not found in the vertebral body. Murakami H, Kawahara N, Gabata T, et al: Vertebral body osteonecrosis without vertebral collapse. Spine 2003;28:E323-E328.

Question 6927

Topic: 2. Trauma

A 72-year-old man presents with an acute Type II odontoid fracture following a fall. His fracture is posteriorly displaced by 6 mm.

Which of the following factors places him at the highest risk for nonunion with nonoperative management?

. Age over 65 years
. Fracture displacement greater than 5 mm
. Posterior direction of displacement
. Associated mild head injury
. Pre-existing cervical spondylosis

Correct Answer & Explanation

. Fracture displacement greater than 5 mm

Explanation

Risk factors for nonunion in Type II odontoid fractures include displacement > 5 mm, angulation > 10 degrees, and age > 50 years. Displacement > 5 mm is generally considered the strongest independent predictor of nonunion.

Question 6928

Topic: Pelvic & Acetabular Trauma

A 65-year-old man is evaluated for mild mid-back stiffness. Radiographs reveal flowing ossification along the anterolateral aspect of the thoracic vertebrae with preservation of disc height and no evidence of sacroiliac joint erosions. To meet the Resnick diagnostic criteria for Diffuse Idiopathic Skeletal Hyperostosis (DISH), this flowing ossification must bridge at least how many contiguous vertebral bodies?

. Two
. Three
. Four
. Five
. Six

Correct Answer & Explanation

. Four

Explanation

The diagnostic criteria for DISH established by Resnick include the presence of flowing ossification along the anterolateral aspect of at least four contiguous vertebral bodies, relative preservation of intervertebral disc height, and absence of apophyseal joint ankylosis or sacroiliac erosions.

Question 6929

Topic: 2. Trauma
According to the Denis classification of sacral fractures, fractures involving Zone III are most highly associated with which of the following clinical complications?
. Sacroiliac joint nonunion
. L5 nerve root injury
. Bowel, bladder, and sexual dysfunction
. Sciatic nerve entrapment
. Superior gluteal artery laceration

Correct Answer & Explanation

. Bowel, bladder, and sexual dysfunction

Explanation

Denis Zone III sacral fractures involve the central sacral canal. Because they directly disrupt the bilateral sacral neural elements, they carry the highest risk (greater than 50%) of neurological deficits, specifically saddle anesthesia and bowel, bladder, or sexual dysfunction.

Question 6930

Topic: 2. Trauma

A 30-year-old man falls from a ladder and sustains a traumatic fracture of the L1 vertebra. According to the Denis three-column classification system, which of the following features defines a burst fracture and differentiates it from a simple compression fracture?

. Failure of the anterior column in tension
. Involvement and failure of the middle column
. Presence of a neurological deficit
. Complete rupture of the posterior ligamentous complex
. Bilateral facet dislocation

Correct Answer & Explanation

. Involvement and failure of the middle column

Explanation

Under the Denis classification, a burst fracture involves failure of both the anterior and middle columns under axial loading. A simple compression fracture involves only the anterior column, leaving the middle column intact and protecting the spinal canal.

Question 6931

Topic: 2. Trauma

A 72-year-old man presents with severe neck pain following a ground-level fall. CT imaging reveals a Type II odontoid fracture with 6 mm of posterior displacement. He is neurologically intact. Which of the following factors is most strongly predictive of nonunion if this patient is treated conservatively with a halo vest?

. Posterior displacement direction
. Associated mandible fracture
. The presence of cervical spondylosis
. Patient age greater than 65 years
. Intact neurological status

Correct Answer & Explanation

. Patient age greater than 65 years

Explanation

In Type II odontoid fractures, patient age greater than 65 years, displacement greater than 5 mm, and a fracture gap greater than 1 mm are significant risk factors for nonunion with conservative management.

Question 6932

Topic: 2. Trauma

A 30-year-old man presents with severe central cord syndrome following a hyperextension injury. MRI reveals severe cervical stenosis and cord edema, but no evidence of fracture or instability. Regarding the timing of surgical decompression, what does current literature suggest?

. Immediate emergency surgery within 4 hours is mandatory
. Early surgery (<24 hours) is associated with improved neurologic recovery
. Surgery should be delayed at least 6 weeks to allow cord edema to resolve
. Steroids must be administered for 48 hours prior to any surgical intervention
. Surgery is strictly contraindicated in central cord syndrome without fracture

Correct Answer & Explanation

. Early surgery (<24 hours) is associated with improved neurologic recovery

Explanation

Recent evidence supports that early surgical decompression (less than 24 hours) provides better neurologic outcomes and shorter hospital stays compared to delayed surgery in patients with acute central cord syndrome.

Question 6933

Topic: 2. Trauma

Which of the following is considered a significant risk factor for nonunion of a Type II odontoid fracture treated nonoperatively with a halo vest?

. Age less than 40 years
. Anterior displacement of 2 mm
. Fracture gap of 1 mm
. Displacement greater than 5 mm
. Posterior angulation of 5 degrees

Correct Answer & Explanation

. Displacement greater than 5 mm

Explanation

Risk factors for nonunion in Type II odontoid fractures include age > 65 years, displacement > 5 mm, posterior displacement, and angulation > 10 degrees. These patients often require surgical stabilization.

Question 6934

Topic: 2. Trauma
A 75-year-old woman sustains a Type II odontoid fracture after a low-energy fall. Surgical stabilization is being considered due to a high risk of nonunion. Which of the following fracture characteristics is an absolute contraindication to anterior odontoid screw fixation?
. Patient age greater than 70 years
. Displacement of 3 mm
. Anterosuperior to posteroinferior fracture line
. Posterosuperior to anteroinferior fracture line
. Acute fracture less than 1 week old

Correct Answer & Explanation

. Anterosuperior to posteroinferior fracture line

Explanation

An anterior-superior to posterior-inferior fracture line (barrel vault variant) is an absolute contraindication to anterior screw fixation. Inserting a screw anteriorly in this pattern will cause the fracture to shear and displace rather than compress.

Question 6935

Topic: 2. Trauma

A 24-year-old woman involved in a high-speed motor vehicle collision wearing only a lap belt presents with severe back pain. Radiographs reveal a transverse fracture through the spinous process, pedicles, and vertebral body of L2. What is the primary mechanism of this injury?

. Axial loading
. Flexion-distraction
. Hyperextension
. Lateral compression
. Rotational shear

Correct Answer & Explanation

. Flexion-distraction

Explanation

The injury described is a Chance fracture, classically associated with lap belt injuries in motor vehicle collisions. The mechanism is flexion-distraction, leading to tension failure of the middle and posterior columns.

Question 6936

Topic: 2. Trauma

When utilizing an anterolateral approach to the distal tibia for open reduction and internal fixation of a pilon fracture, which neurologic structure is at greatest risk of iatrogenic injury during the superficial surgical dissection?

. Sural nerve
. Deep peroneal nerve
. Superficial peroneal nerve
. Saphenous nerve
. Tibial nerve

Correct Answer & Explanation

. Superficial peroneal nerve

Explanation

The superficial peroneal nerve crosses the surgical field as it transitions from the lateral compartment to the anterior aspect of the leg. It must be identified and protected during the anterolateral approach to the distal tibia.

Question 6937

Topic: 2. Trauma

In the Sanders classification of intra-articular calcaneal fractures, the primary prognostic variable that determines the classification type is the number and location of fracture lines through which of the following structures?

. Anterior facet of the calcaneus
. Middle facet of the calcaneus
. Posterior facet of the calcaneus
. Calcaneocuboid joint
. Sustentaculum tali

Correct Answer & Explanation

. Posterior facet of the calcaneus

Explanation

The Sanders classification is based on coronal CT scan images and categorizes calcaneal fractures based on the number of primary fracture lines through the posterior articular facet. The severity correlates with the degree of comminution of this specific facet.

Question 6938

Topic: 2. Trauma

A 35-year-old man sustains a severe ankle injury. Radiographs reveal a fracture-dislocation where the proximal fibular fragment is irreducible by closed means.

Intraoperative exploration demonstrates entrapment of the fibula behind the posterior tubercle of the distal tibia. What is the diagnosis?

. Maisonneuve fracture
. Bosworth fracture
. Tillaux fracture
. Chaput fracture
. Wagstaffe fracture

Correct Answer & Explanation

. Bosworth fracture

Explanation

A Bosworth fracture is a rare fracture-dislocation of the ankle where the proximal fibular fragment becomes locked behind the posterior tubercle of the distal tibia. This entrapment makes closed reduction impossible, necessitating open reduction.

Question 6939

Topic: 2. Trauma

A 45-year-old man sustains an ankle fracture. Radiographs and CT scan demonstrate a lateral malleolus fracture and a posterior malleolus fracture involving 35% of the tibial articular surface with step-off. According to current biomechanical and clinical guidelines, what is the most appropriate management of the posterior malleolus?

. Nonoperative management in a cast
. Open reduction and internal fixation of both the lateral and posterior malleoli
. Open reduction and internal fixation of the lateral malleolus only
. Primary ankle arthrodesis
. Spanning external fixation without internal fixation

Correct Answer & Explanation

. Open reduction and internal fixation of both the lateral and posterior malleoli

Explanation

Current literature supports open reduction and internal fixation of posterior malleolus fractures involving >25% of the articular surface or those associated with syndesmotic instability. Fixation restores the articular surface and improves syndesmotic stability better than syndesmotic screws alone.

Question 6940

Topic: 2. Trauma

A 30-year-old man presents with a high-energy closed ankle injury. The ankle is grossly deformed and irreducible in the emergency department. Radiographs demonstrate the proximal fragment of the fibula entrapped posterior to the lateral tubercle of the distal tibia. What is the correct diagnosis?

. Maisonneuve fracture
. Tillaux fracture
. Bosworth fracture-dislocation
. Wagstaffe fracture
. Chaput fracture

Correct Answer & Explanation

. Bosworth fracture-dislocation

Explanation

A Bosworth fracture-dislocation is a rare, severe injury where the proximal fibular fragment dislocates posterior to the incisura fibularis of the tibia. It is characteristically irreducible by closed means and requires prompt open reduction.

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