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2. Trauma MCQs

Practice Set 98 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 1941

Topic: 2. Trauma

A 60-year-old female sustains an AO/OTA 13-C3 comminuted intra-articular distal humerus fracture. An olecranon osteotomy is utilized to gain optimal articular visualization. Which of the following is the most common complication specifically associated with the olecranon osteotomy approach?

. Triceps weakness and lag
. Iatrogenic ulnar nerve palsy
. Symptomatic hardware requiring removal or nonunion of the osteotomy site
. Severe heterotopic ossification
. Avascular necrosis of the trochlea

Correct Answer & Explanation

. Symptomatic hardware requiring removal or nonunion of the osteotomy site

Explanation

While an olecranon osteotomy provides excellent exposure for complex distal humerus fractures, its most frequent complication is symptomatic hardware (tension band or plate) necessitating removal. Delayed union or nonunion of the osteotomy site is also a recognized complication of this approach.

Question 1942

Topic: 2. Trauma

A 50-year-old female with poorly controlled diabetes presents with a high-energy pilon fracture (AO/OTA 43-C). The soft tissues are severely swollen with extensive fracture blisters. The decision is made to place a temporizing joint-spanning external fixator. At what anatomical location should the proximal pins ideally be placed?

. Distal third of the tibial diaphysis
. Inside the zone of anticipated definitive plate coverage
. Proximal half of the tibial diaphysis, anterior to the crest
. Directly into the subchondral bone of the distal tibia
. Through the medial malleolus into the talar dome

Correct Answer & Explanation

. Proximal half of the tibial diaphysis, anterior to the crest

Explanation

To minimize the risk of subsequent deep infection, external fixator pins must be placed well outside the future zone of definitive internal fixation. For pilon fractures, proximal pins are safely placed in the intact proximal half of the tibial diaphysis.

Question 1943

Topic: 2. Trauma

A 40-year-old male sustains a closed intra-articular calcaneus fracture after a fall.

The Sanders classification is used to guide treatment. Which specific imaging view and anatomical landmark does this classification system primarily evaluate?

. Sagittal CT reconstruction of the anterior process
. Coronal CT view evaluating the number of fracture lines through the posterior facet
. Axial CT view evaluating displacement of the sustentaculum tali
. Lateral plain radiograph evaluating Bohler's angle depression
. Harris axial radiograph evaluating lateral wall blowout

Correct Answer & Explanation

. Coronal CT view evaluating the number of fracture lines through the posterior facet

Explanation

The Sanders classification relies on a coronal CT image demonstrating the widest point of the posterior facet of the calcaneus. It categorizes fractures based on the number and location of primary fracture lines extending through the posterior facet, which correlates strongly with prognosis.

Question 1944

Topic: 2. Trauma
A 24-year-old male presents following a motor vehicle collision with lower back pain. An axial CT scan of his sacrum is shown below. Based on the fracture pattern identified, what is the most likely rate of associated neurological deficit (lower extremity symptoms or bowel/bladder/sexual dysfunction)?
. A. Less than 5%
. B. Approximately 15%
. C. Approximately 28%
. D. Approximately 45%
. E. Greater than 55%

Correct Answer & Explanation

. C. Approximately 28%

Explanation

Correct Answer: C. Approximately 28%. The image provided is an axial CT scan of the sacrum, which clearly demonstrates a fracture line extending through the right sacral foramen. According to the Denis classification of sacral fractures, a fracture that passes through the sacral foramen is classified as a Denis Type II injury. The case discussion explicitly states that Denis Type II sacral fractures are associated with a 28% rate of neurological injury.

Question 1945

Topic: 2. Trauma
A 24-year-old male sustains a sacral fracture as depicted in the axial CT scan. Which of the following best describes the Denis classification of this fracture?
. Denis Type I
. Denis Type II
. Denis Type III
. Transverse fracture (Roy-Camille Type I)
. U-type sacral fracture

Correct Answer & Explanation

. Denis Type II

Explanation

The axial CT scan clearly shows a fracture line traversing the sacral foramen on the right side. The Denis classification categorizes sacral fractures based on their relationship to the sacral foramen and central canal: Denis Type I: Fractures occurring lateral to the sacral foramen. Denis Type II: Fractures passing through the sacral foramen. Denis Type III: Fractures involving the central sacral canal, medial to the sacral foramen.

Question 1946

Topic: 2. Trauma
A 24-year-old male presents with a sacral fracture. Based on the principles discussed in the case, nonsurgical treatment would be considered a reasonable option in all of the following scenarios, EXCEPT which of the following?
. A neurologically intact patient with a nondisplaced transverse fracture at the level of the S4 foramen.
. A neurologically intact patient with a unilateral nondisplaced Denis Type II fracture involving only the ventral sacral cortex.
. A neurologically intact patient with a unilateral displaced Denis Type I fracture involving both the ventral and dorsal cortices.
. A neurologically intact elderly patient with bilateral nondisplaced Denis Type II fracture involving only the ventral cortex.
. A neurologically intact patient with a minimally displaced Denis Type I fracture without spinopelvic instability.

Correct Answer & Explanation

. A neurologically intact elderly patient with bilateral nondisplaced Denis Type II fracture involving only the ventral cortex.

Explanation

Nonsurgical management is typically reserved for patients with sacral fracture morphology that does not compromise spinopelvic stability. A unilateral displaced Denis Type I fracture involving both the ventral and dorsal cortices signifies significant disruption of the sacral ring. Displacement and involvement of both cortices indicate a higher degree of instability, which would typically necessitate surgical stabilization.

Question 1947

Topic: 2. Trauma

A 24-year-old male with a sacral fracture (as shown in the axial CT) is undergoing percutaneous sacroiliac screw fixation. To minimize the risk of iatrogenic foot drop due to aberrant hardware placement, which intraoperative fluoroscopic view is most critical for assessing the anterior-to-posterior trajectory of the screw?

. A. Obturator outlet pelvic view
. B. Iliac oblique pelvic view
. C. Pelvic inlet view
. D. True lateral sacral view
. E. AP pelvic view

Correct Answer & Explanation

. C. Pelvic inlet view

Explanation

Correct Answer: C. Pelvic inlet viewThe case discussion explicitly states that the pelvic inlet view is crucial for visualizing the anterior-to-posterior trajectory of the sacroiliac screw. This view allows the surgeon to monitor the screw's progression and prevent anterior breach, which could injure the lower lumbar nerve roots (specifically L5, which contributes to the peroneal nerve and thus foot dorsiflexion, leading to foot drop) that drape over the ventral surface of the sacral ala.Option A (Obturator outlet pelvic view):This view is primarily used to assess the superior-to-inferior trajectory of the screw and ensure it remains within the sacral body, avoiding the greater sciatic notch and sacral foramina. It is less effective for anterior breach.Option B (Iliac oblique pelvic view):This view is used to assess the screw's position within the ilium and sacrum in the coronal plane, ensuring it is not too medial or lateral. It does not provide the necessary anterior-to-posterior trajectory assessment.Option D (True lateral sacral view):While useful for assessing the overall length and trajectory in the sagittal plane, the inlet view is superior for specifically identifying anterior cortical breach in the axial plane, especially concerning the anterior neurovascular structures.Option E (AP pelvic view):The AP view provides a general overview but is insufficient for detailed assessment of screw trajectory in the critical anterior-posterior dimension to prevent anterior breach.

Question 1948

Topic: 2. Trauma
A 68-year-old female with osteoporosis presents with a sacral insufficiency fracture. Preoperative planning for potential percutaneous sacroiliac screw fixation includes assessing for sacral dysmorphism. All of the following radiographic findings are indicative of sacral dysmorphism, EXCEPT which of the following?
. The sacrum is not recessed within the pelvis on the outlet image.
. Mammillary processes are seen on the outlet image.
. A residual disc space between the upper two sacral segments is seen on the outlet image.
. Paradoxical inlet view of the upper sacral segments on the AP or outlet views.
. 'Tongue-in-groove' SI articulations noted on the CT scan.

Correct Answer & Explanation

. Paradoxical inlet view of the upper sacral segments on the AP or outlet views.

Explanation

The finding of a paradoxical inlet view of the upper sacral segments on the AP or outlet views represents an occult sacral fracture dislocation or a U-type sacral fracture, not sacral dysmorphism. This is a critical distinction for diagnosis and treatment planning.

Question 1949

Topic: 2. Trauma
A 35-year-old male presents with a sacral fracture that extends medial to the sacral foramen, involving the central sacral canal. According to the Denis classification, what is the expected rate of neurological injury for this fracture pattern?
. 6%
. 28%
. 45%
. 57%
. 75%

Correct Answer & Explanation

. 57%

Explanation

The question describes a sacral fracture that extends medial to the sacral foramen, involving the central sacral canal. This is the definition of a Denis Type III sacral fracture. The neurological injury rates for each Denis type are: Denis Type I (lateral to foramen): 6%; Denis Type II (through sacral foramen): 28%; Denis Type III (medial to foramen, involving central canal): 57%.

Question 1950

Topic: 2. Trauma

A 24-year-old male presents with a sacral fracture, as shown in the axial CT scan. If this patient were to undergo surgical fixation, which of the following fracture characteristics would most strongly indicate the need for surgical stabilization rather than conservative management?

. A. A neurologically intact patient with a nondisplaced transverse fracture at S4.
. B. A unilateral nondisplaced Denis Type II fracture involving only the ventral cortex.
. C. A neurologically intact elderly patient with bilateral nondisplaced Denis Type II fractures involving only the ventral cortex.
. D. A displaced Denis Type I fracture involving both the ventral and dorsal cortices.
. E. A minimally displaced Denis Type I fracture without spinopelvic instability.

Correct Answer & Explanation

. D. A displaced Denis Type I fracture involving both the ventral and dorsal cortices.

Explanation

Correct Answer: D. A displaced Denis Type I fracture involving both the ventral and dorsal cortices.The case discussion emphasizes that nonsurgical management is reserved for sacral fracture morphologies thatdo not compromise spinopelvic stability. Conversely, characteristics that indicate instability would necessitate surgical stabilization.Option A (A neurologically intact patient with a nondisplaced transverse fracture at S4):This is explicitly mentioned as a scenario where nonsurgical management is reasonable, indicating stability.Option B (A unilateral nondisplaced Denis Type II fracture involving only the ventral cortex):This is also mentioned as a scenario for conservative treatment, implying stability due to lack of displacement and limited cortical involvement.Option C (A neurologically intact elderly patient with bilateral nondisplaced Denis Type II fractures involving only the ventral cortex):Similar to option B, nondisplacement and limited cortical involvement suggest stability, making conservative treatment a possibility.Option D (A displaced Denis Type I fracture involving both the ventral and dorsal cortices):This scenario is explicitly stated in the case as theexceptionwhere nonsurgical treatment isnotconsidered reasonable. Displacement, especially involving both cortices, indicates significant disruption of the sacral ring and compromise of spinopelvic stability, thus requiring surgical intervention.Option E (A minimally displaced Denis Type I fracture without spinopelvic instability):Minimally displaced fractures, particularly if stable, are often managed conservatively.Therefore, a displaced fracture involving both cortices is the strongest indicator for surgical stabilization among the choices provided, as it directly implies instability.

Question 1951

Topic: 2. Trauma

A 72-year-old female with severe osteoporosis presents with a sacral insufficiency fracture. During preoperative assessment, a CT scan reveals a 'tongue-in-groove' appearance of the sacroiliac joint. This finding is indicative of which of the following?

. A. Normal age-related degenerative changes of the SI joint.
. B. An acute traumatic sacroiliac joint dislocation.
. C. Sacral dysmorphism, potentially complicating hardware placement.
. D. A chronic inflammatory arthropathy affecting the SI joint.
. E. An occult sacral fracture dislocation.

Correct Answer & Explanation

. C. Sacral dysmorphism, potentially complicating hardware placement.

Explanation

Correct Answer: C. Sacral dysmorphism, potentially complicating hardware placement.The case discussion lists 'โ€œTongue-in-grooveโ€ SI articulations are noted on the CT scan' as one of the predictable dysplastic patterns that can be easily identified using CT scans and represents sacral dysmorphism. Sacral dysmorphism is a collective term for aberrations in sacral osteology that may preclude safe hardware placement if not recognized preoperatively.Option A (Normal age-related degenerative changes of the SI joint):While degenerative changes occur, 'tongue-in-groove' is a specific morphological variation indicative of dysmorphism, not just typical degeneration.Option B (An acute traumatic sacroiliac joint dislocation):A dislocation implies a complete loss of articulation, which is different from a 'tongue-in-groove' morphology, although dysmorphism can predispose to instability.Option D (A chronic inflammatory arthropathy affecting the SI joint):Inflammatory arthropathies like ankylosing spondylitis cause characteristic erosions, sclerosis, and eventual fusion, which are distinct from a 'tongue-in-groove' appearance.Option E (An occult sacral fracture dislocation):While occult fracture dislocations are important to identify, the 'tongue-in-groove' finding itself is a feature of dysmorphism, not a fracture dislocation. A paradoxical inlet view, as mentioned in the case, is indicative of an occult fracture dislocation.

Question 1952

Topic: 2. Trauma
A 28-year-old male presents with a high-energy pelvic injury. Radiographs and CT scans confirm a sacral fracture. The surgeon notes that the sacral alar slope appears acute on the lateral view. This finding should alert the surgeon to the possibility of:
. A stable transverse sacral fracture.
. A Denis Type III sacral fracture with high neurological risk.
. Sacral dysmorphism, requiring careful preoperative planning for screw placement.
. An isolated sacral avulsion fracture.
. A chronic stress fracture of the sacrum.

Correct Answer & Explanation

. Sacral dysmorphism, requiring careful preoperative planning for screw placement.

Explanation

The alar slope being acute on the lateral view is one of the predictable dysplastic patterns that can be easily identified using plain radiographs and CT scans, falling under the umbrella of sacral dysmorphism. Sacral dysmorphism refers to anatomical variations in the sacrum that can make standard percutaneous sacroiliac screw placement challenging and increase the risk of iatrogenic injury.

Question 1953

Topic: 2. Trauma

A 40-year-old male presents with a complex sacral fracture following a fall from height. The fracture pattern involves bilateral vertical sacral fractures connected by a transverse component, resulting in spinopelvic dissociation. This specific fracture pattern is often associated with which of the following radiographic findings?

. A. Mammillary processes seen on the outlet image.
. B. An acute alar slope on the lateral view.
. C. A residual disc space between the upper two sacral segments on the outlet view.
. D. Paradoxical inlet view of the upper sacral segments on the AP or outlet views.
. E. 'Tongue-in-groove' SI articulations on the CT scan.

Correct Answer & Explanation

. D. Paradoxical inlet view of the upper sacral segments on the AP or outlet views.

Explanation

Correct Answer: D. Paradoxical inlet view of the upper sacral segments on the AP or outlet views.The question describes a U-type or H-type sacral fracture, which is a severe, unstable injury leading to spinopelvic dissociation. The case discussion explicitly states that a 'Paradoxical inlet view of the upper sacral segments on the AP or outlet views' represents 'occult sacral fracture dislocation or U-type sacral fracture.' This finding is a key radiographic indicator of this highly unstable injury pattern.Options A, B, C, and E:These options (mammillary processes, acute alar slope, residual disc space between upper two sacral segments, and 'tongue-in-groove' SI articulations) are all listed in the case discussion as characteristics ofsacral dysmorphism. While sacral dysmorphism can complicate surgery and potentially influence fracture patterns, these findings themselves do not represent an acute U-type fracture or spinopelvic dissociation. The paradoxical inlet view is the specific finding linked to this severe injury pattern in the provided text.

Question 1954

Topic: 2. Trauma
A 35-year-old male is involved in a high-speed motor vehicle collision. CT imaging demonstrates a sacral fracture extending medial to the sacral foramina. What is the most likely neurological complication associated with this specific fracture pattern?
. Unilateral L5 radiculopathy
. Bowel and bladder dysfunction
. Isolated foot drop
. Pudendal neuralgia without sphincter involvement
. Femoral nerve palsy

Correct Answer & Explanation

. Bowel and bladder dysfunction

Explanation

This describes a Denis Zone III (central) sacral fracture, which carries the highest risk of neurological injury (up to 57%). These injuries frequently involve the S2-S4 nerve roots, leading to bowel, bladder, and sexual dysfunction.

Question 1955

Topic: 2. Trauma

Which of the following best describes the anatomical location and corresponding neurological risk of a Denis Zone I sacral fracture?

. Medial to the foramina; 57% risk of neuro deficit
. Through the foramina; 28% risk of neuro deficit
. Transverse through S1; 80% risk of neuro deficit
. Lateral to the foramina; 6% risk of neuro deficit
. Involving the sacroiliac joint exclusively; 15% risk of neuro deficit

Correct Answer & Explanation

. Lateral to the foramina; 6% risk of neuro deficit

Explanation

Denis Zone I fractures occur in the sacral ala lateral to the sacral foramina. They have the lowest rate of neurological injury among the Denis zones, approximately 6%, typically involving the L5 nerve root if present.

Question 1956

Topic: 2. Trauma

A patient sustains a U-type sacral fracture following a fall from height. Which of the following statements is true regarding this injury pattern?

. It is characterized by an isolated transverse fracture below S4.
. It represents a form of spinopelvic dissociation requiring lumbopelvic fixation.
. Conservative management is the gold standard due to high nonunion rates with surgery.
. It primarily occurs as an insufficiency fracture in osteoporotic females.
. Neurological deficits are exceptionally rare in this fracture pattern.

Correct Answer & Explanation

. It represents a form of spinopelvic dissociation requiring lumbopelvic fixation.

Explanation

U-type sacral fractures consist of bilateral longitudinal fractures connected by a transverse fracture component, resulting in spinopelvic dissociation. Due to severe instability and a high rate of neurological compromise, lumbopelvic fixation is generally indicated.

Question 1957

Topic: 2. Trauma
A 29-year-old female presents with severe back pain after a high-energy fall. A CT scan of her pelvis is obtained. If this imaging demonstrates a fracture extending through the central sacral canal, which classification and treatment principle apply?
. Denis Zone I; typically treated with early weight-bearing.
. Denis Zone II; routinely treated with sacral laminectomy.
. Denis Zone III; surgical decompression may be required if bowel/bladder deficits are present.
. Denis Zone III; absolute indication for immediate amputation.
. Denis Zone I; highest risk of sexual dysfunction.

Correct Answer & Explanation

. Denis Zone III; surgical decompression may be required if bowel/bladder deficits are present.

Explanation

Central sacral canal fractures are classified as Denis Zone III. They carry the highest risk of neurological deficits, and surgical decompression with stabilization is often required when bowel, bladder, or severe sacral root deficits are present.

Question 1958

Topic: 2. Trauma

A 33-year-old male undergoes surgical fixation of a complex sacral fracture and associated pelvic ring injury. When is the optimal time to initiate pharmacological VTE prophylaxis postoperatively, assuming no ongoing hemorrhage?

. Immediately in the recovery room
. 12 to 24 hours postoperatively
. 72 to 96 hours postoperatively
. 1 week postoperatively
. Only upon hospital discharge

Correct Answer & Explanation

. 12 to 24 hours postoperatively

Explanation

For high-risk orthopedic trauma patients, including those with pelvic and sacral fractures, guidelines generally recommend initiating pharmacological VTE prophylaxis 12 to 24 hours postoperatively, provided hemostasis is achieved.

Question 1959

Topic: 2. Trauma

A 55-year-old female sustains a transverse sacral fracture at the S4 level following a slip and fall. She has normal sphincter tone and no lower extremity neurological deficits. What is the most appropriate initial management?

. Immediate spinopelvic fixation
. Sacral laminectomy and nerve root decompression
. Symptomatic treatment and protected weight-bearing
. Iliosacral screw fixation
. Transforaminal epidural steroid injection

Correct Answer & Explanation

. Symptomatic treatment and protected weight-bearing

Explanation

Transverse sacral fractures occurring below the S4 level rarely compromise spinopelvic stability or the primary nerve roots supplying the lower extremities or sphincters. They are typically managed non-operatively with symptomatic care and protected weight-bearing.

Question 1960

Topic: 2. Trauma

A patient with an unstable Denis Zone I sacral fracture with cranial displacement of the alar fragment presents with a new neurological deficit. Which physical examination finding is most consistent with the injured nerve root?

. Loss of Achilles tendon reflex
. Weakness in extensor hallucis longus (EHL)
. Decreased sensation over the medial malleolus
. Weakness in knee extension
. Loss of anal wink reflex

Correct Answer & Explanation

. Weakness in extensor hallucis longus (EHL)

Explanation

Denis Zone I fractures (alar fractures) can cause L5 nerve root injury, particularly if there is cranial displacement or compression by the L5 transverse process. L5 radiculopathy characteristically presents with weakness in great toe extension (EHL).

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