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2. Trauma MCQs

Practice Set 562 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 11221

Topic: 2. Trauma

A 32-year-old male with a closed tibial shaft fracture is complaining of out-of-proportion pain 12 hours post-injury. You suspect acute compartment syndrome. Which of the following pressure measurement thresholds is the most accurate indication for emergent fasciotomy?

. Absolute compartment pressure > 30 mmHg
. Absolute compartment pressure > 45 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 < 30 mmHg accurately indicates a perfusion deficit requiring emergent fasciotomy, minimizing unnecessary surgeries compared to using an absolute pressure threshold.

Question 11222

Topic: 2. Trauma

A 45-year-old male is involved in a high-speed motor vehicle collision. Radiographs and CT demonstrate an acetabular fracture. The obturator oblique view reveals a pathognomonic 'spur sign'. This radiographic finding is indicative of which Letournel and Judet fracture pattern?

. Anterior column fracture
. Both-column fracture
. T-type fracture
. Transverse fracture
. Posterior wall fracture

Correct Answer & Explanation

. Both-column fracture

Explanation

The 'spur sign' represents the stable, intact portion of the ilium that remains attached to the axial skeleton, projecting posterior-inferiorly above the displaced acetabular articular fragments. It is best seen on the obturator oblique radiograph and is pathognomonic for a both-column acetabular fracture.

Question 11223

Topic: 2. Trauma
A 50-year-old male sustains a knee injury classified as a Schatzker IV tibial plateau fracture. Which of the following best describes this specific fracture pattern?
. Pure cleavage fracture of the lateral plateau
. Cleavage and depression of the lateral plateau
. Pure depression of the lateral plateau
. Fracture of the medial tibial plateau
. Bicondylar tibial plateau fracture

Correct Answer & Explanation

. Fracture of the medial tibial plateau

Explanation

In the Schatzker classification: I is lateral split, II is lateral split-depression, III is lateral pure depression, IV is medial plateau fracture, V is bicondylar fracture, and VI is plateau fracture with metaphyseal-diaphyseal dissociation. Schatzker IV injuries are often high-energy varus forces with a high risk of vascular injury and compartment syndrome.

Question 11224

Topic: 2. Trauma

A 22-year-old male is evaluated in the ER after sustaining a low-velocity civilian gunshot wound to the thigh, resulting in a midshaft femur fracture. The bullet tracked directly through the thigh with no gross wound contamination or expanding hematoma. What is the standard of care for definitive management?

. Intravenous antibiotics for 72 hours, immediate extensive excisional debridement, and external fixation
. Oral antibiotics, local wound care, and intramedullary nailing within 24 hours
. Intravenous antibiotics, superficial wound care, and standard intramedullary nailing
. No antibiotics are necessary; perform immediate plate osteosynthesis
. Formal tracking debridement of the bullet path in the OR followed by skeletal traction

Correct Answer & Explanation

. Intravenous antibiotics, superficial wound care, and standard intramedullary nailing

Explanation

Low-velocity gunshot fractures of the femur without gross contamination or vascular injury are treated similarly to closed fractures. Standard management involves superficial local wound care, a short course of IV antibiotics, and antegrade intramedullary nailing. Extensive excisional debridement of the bullet track is unnecessary and can increase morbidity.

Question 11225

Topic: 2. Trauma

In the concept of Damage Control Orthopedics (DCO), the 'second hit' phenomenon can precipitate systemic inflammatory response syndrome (SIRS) and acute respiratory distress syndrome (ARDS). Which of the following cytokines is most strongly correlated with the severity of this secondary inflammatory response and is routinely measured in European trauma protocols to guide timing of definitive surgery?

. Interleukin-1 (IL-1)
. Interleukin-6 (IL-6)
. Tumor Necrosis Factor alpha (TNF-a)
. Transforming Growth Factor beta (TGF-b)
. Interferon-gamma

Correct Answer & Explanation

. Interleukin-6 (IL-6)

Explanation

Interleukin-6 (IL-6) is a key mediator and the most sensitive inflammatory marker for predicting the severity of the systemic inflammatory response following major trauma (the 'first hit') and the magnitude of the 'second hit' induced by extensive surgery. An IL-6 level > 500 pg/mL is often considered a threshold favoring DCO over ETC.

Question 11226

Topic: 2. Trauma
A 28-year-old polytrauma patient sustains bilateral femur fractures and a blunt chest injury. He is initially managed with temporary external fixation (Damage Control Orthopedics). Which of the following biochemical parameters most reliably indicates that the patient is physiologically optimized for conversion to definitive intramedullary nailing (Early Total Care)?
. Interleukin-6 (IL-6) levels reaching peak concentration
. Normalization of base deficit (> -2.0 mmol/L) and lactate (< 2.5 mmol/L)
. Persistent hyperlactatemia (> 4.0 mmol/L) with normal pH
. Platelet count dropping below 90,000/ฮผL
. INR > 1.5 with clinical evidence of coagulopathy

Correct Answer & Explanation

. Normalization of base deficit (> -2.0 mmol/L) and lactate (< 2.5 mmol/L)

Explanation

According to the principles of Damage Control Orthopedics (DCO) vs. Early Total Care (ETC), optimal timing for definitive fixation in a polytrauma patient relies heavily on adequate physiological resuscitation. The most reliable systemic markers of adequate tissue perfusion and resuscitation are a cleared serum lactate (< 2.5 mmol/L) and a normalized base deficit (typically > -2.0 mmol/L or resolving to normal limits). Operating during the 'window of opportunity' (days 5-10) when these parameters are normal minimizes the 'second hit' of surgery.

Question 11227

Topic: 2. Trauma

A 40-year-old male sustains a high-energy posterior shear fracture of the medial tibial plateau (Schatzker IV variant).

What is the optimal surgical approach to directly visualize and buttress this specific posteromedial fragment?

. Standard anterolateral approach
. Direct posterior approach through the popliteal fossa
. Posteromedial approach utilizing the interval between the medial head of the gastrocnemius and the pes anserinus
. Direct medial approach centered over the medial collateral ligament
. Midline transpatellar tendon approach

Correct Answer & Explanation

. Posteromedial approach utilizing the interval between the medial head of the gastrocnemius and the pes anserinus

Explanation

Posteromedial shear fractures of the tibial plateau cannot be effectively reduced or buttressed via an anterior or anterolateral approach. The optimal approach is the posteromedial approach, which utilizes the interval between the medial head of the gastrocnemius (retracted laterally with the neurovascular bundle) and the pes anserinus/semimembranosus (retracted medially). This allows direct application of an anti-glide or buttress plate to the posterior aspect of the medial plateau.

Question 11228

Topic: 2. Trauma
A 35-year-old presents with a Grade IIIB open tibia fracture requiring a local rotational flap for coverage. Following current evidence-based guidelines (e.g., the EAST guidelines/Surgical Infection Society), what is the currently recommended protocol for systemic antibiotic prophylaxis duration following definitive soft-tissue wound closure?
. Discontinue systemic antibiotics within 24 hours after successful definitive wound closure
. Continue systemic IV antibiotics for 7 days post-coverage
. Continue oral antibiotics until radiographic bone union is evident
. 5 days of IV antibiotics followed by 10 days of broad-spectrum oral antibiotics
. Discontinue immediately post-initial debridement, regardless of closure timing

Correct Answer & Explanation

. Discontinue systemic antibiotics within 24 hours after successful definitive wound closure

Explanation

For severe open fractures (Gustilo-Anderson Grade III), updated guidelines from the Surgical Infection Society and Eastern Association for the Surgery of Trauma (EAST) recommend stopping prophylactic systemic antibiotics either 72 hours after the initial injury or within 24 hours of successful, definitive soft-tissue coverage (whichever occurs first). Prolonging antibiotic prophylaxis beyond this timeframe does not decrease infection rates and increases the risk of antimicrobial resistance and C. difficile infections.

Question 11229

Topic: 2. Trauma

A 22-year-old male polytrauma patient presents with severe traumatic brain injury (GCS 6, ICP 25 mmHg) and bilateral closed femoral shaft fractures. He has been hemodynamically resuscitated in the ICU. Which of the following is the most appropriate orthopedic management strategy for his femur fractures?

. Immediate bilateral antegrade reamed intramedullary nailing
. Bilateral external fixation as Damage Control Orthopedics (DCO)
. Unilateral IM nailing of the more severe side, and traction for the other
. Strict skeletal traction until the patient regains full consciousness
. Open reduction and internal fixation with dynamic compression plates

Correct Answer & Explanation

. Immediate bilateral antegrade reamed intramedullary nailing

Explanation

In a patient with severe Traumatic Brain Injury (GCS < 8) and elevated intracranial pressure (ICP), prolonged surgical procedures and physiological insults (like femoral reaming) can precipitate secondary brain injury (the 'second hit') by inducing hypotension, hypoxia, or severe inflammatory responses. Damage Control Orthopedics (DCO) using rapid external fixation is the treatment of choice. Definitive IM nailing is deferred until the neurologic status and ICP have stabilized.

Question 11230

Topic: 2. Trauma

A 45-year-old male with a high-energy Pilon fracture is initially managed with a spanning external fixator to allow for soft tissue resuscitation. What clinical physical exam finding most reliably indicates that the soft tissue envelope is sufficiently recovered to safely proceed with definitive open reduction and internal fixation (ORIF)?

. Return of capillary refill in the toes to < 2 seconds
. Appearance of skin wrinkles with active or passive dorsiflexion of the ankle
. Conversion of hemorrhagic fracture blisters to clear fluid blisters
. Decrease in maximal calf circumference by at least 1 cm
. Complete epithelialization of all external fixator pin sites

Correct Answer & Explanation

. Return of capillary refill in the toes to < 2 seconds

Explanation

The 'wrinkle sign' is a classic clinical indicator used to assess the resolution of soft tissue edema following lower extremity trauma, particularly Pilon and calcaneus fractures. When skin wrinkles appear upon dorsiflexion or movement, it signifies that the interstitial edema has resolved sufficiently to safely make surgical incisions with a lower risk of wound dehiscence and infection. Blisters must re-epithelialize, not just change fluid type. Pin sites do not dictate incision readiness for the primary fracture.

Question 11231

Topic: 2. Trauma

A 30-year-old male is admitted with a closed tibia fracture. Over the next 12 hours, he complains of worsening leg pain out of proportion to the injury. His blood pressure is 110/70 mmHg. Compartment pressures are measured. Which of the following absolute or differential pressure measurements represents a strict, widely accepted indication for immediate four-compartment fasciotomy?

. An absolute anterior compartment pressure of 25 mmHg
. An absolute deep posterior compartment pressure of 30 mmHg
. A delta pressure (Diastolic BP - Compartment Pressure) of 20 mmHg
. A delta pressure (Diastolic BP - Compartment Pressure) of 45 mmHg
. A difference between Mean Arterial Pressure (MAP) and Compartment Pressure of 40 mmHg

Correct Answer & Explanation

. An absolute anterior compartment pressure of 25 mmHg

Explanation

The diagnosis of acute compartment syndrome is strongly supported by a delta pressure (Diastolic Blood Pressure minus intra-compartmental pressure) of less than 30 mmHg (some sources cite < 20-30 mmHg). An absolute pressure > 30 mmHg was historically used, but it leads to overtreatment, particularly in hypotensive trauma patients. A delta pressure of 20 mmHg means the compartment pressure is dangerously close to the diastolic pressure, compromising capillary perfusion, and mandates fasciotomy.

Question 11232

Topic: 2. Trauma
A 40-year-old motorcyclist sustains a closed lateral compression pelvic fracture. Examination reveals a large, soft, fluctuant swelling over the greater trochanter with localized ecchymosis and decreased cutaneous sensation. What is the precise pathophysiology underlying this specific soft tissue lesion?
. Direct crush injury leading to liquefactive necrosis of the gluteal muscles
. Shearing separation of the skin and subcutaneous fat from the underlying deep fascia, creating a potential space filled with hemolymph
. Rupture of the superior gluteal artery leading to a sub-fascial expanding hematoma
. Traumatic herniation of the vastus lateralis through a tear in the fascia lata
. Displaced bone fragment directly lacerating the dermal venous plexus

Correct Answer & Explanation

. Shearing separation of the skin and subcutaneous fat from the underlying deep fascia, creating a potential space filled with hemolymph

Explanation

This presentation describes a Morel-Lavallรฉe lesion, which is a closed internal degloving injury. The pathophysiology involves the shearing of the skin and subcutaneous tissue from the rigidly fixed underlying deep fascia. This mechanism disrupts the perforating vascular and lymphatic vessels, leading to the accumulation of a serosanguineous, hemolymphatic collection in the newly created potential space. It is highly associated with pelvic and acetabular trauma.

Question 11233

Topic: 2. Trauma

A 25-year-old sustains a talar neck fracture. To assess the viability of the talar body, a physician notes the presence of a subchondral radiolucent band in the dome of the talus on an AP ankle radiograph taken 6-8 weeks post-injury. What does this radiographic finding (Hawkins sign) indicate regarding the talus?

. Impending complete collapse of the talar dome
. Infection (osteomyelitis) of the talar body
. Intact vascular supply to the talar body
. Severe post-traumatic osteoarthritis
. Avascular necrosis (AVN) of the talar body

Correct Answer & Explanation

. Impending complete collapse of the talar dome

Explanation

The Hawkins sign is the appearance of a subchondral radiolucent band in the dome of the talus, typically seen 6-8 weeks following a talar neck fracture on an AP or Mortise radiograph. This radiolucency represents subchondral osteopenia secondary to bone resorption. Because bone resorption requires an active blood supply, the presence of the Hawkins sign is a highly reliable indicator that the talar body remains vascularized, predicting a very low risk of Avascular Necrosis (AVN).

Question 11234

Topic: 2. Trauma

A 35-year-old male presents with a closed, distal third spiral fracture of the humerus (Holstein-Lewis fracture). On initial evaluation in the emergency department, his radial nerve function is completely intact. Following closed reduction and the application of a coaptation splint, repeat examination demonstrates a new complete loss of wrist and finger extension. What is the most appropriate next step in management?

. Obtain an immediate electromyography (EMG) study
. Observe for spontaneous recovery over the next 3 months
. Surgical exploration of the radial nerve and ORIF of the fracture
. Remove the coaptation splint and apply a functional Sarmiento brace
. Administer high-dose intravenous corticosteroids

Correct Answer & Explanation

. Obtain an immediate electromyography (EMG) study

Explanation

A Holstein-Lewis fracture is a spiral fracture of the distal one-third of the humeral shaft, which carries a high risk of radial nerve entrapment as the nerve passes through the lateral intermuscular septum. While primary radial nerve palsies associated with closed humerus fractures are generally observed, asecondarynerve palsy that developsaftera closed reduction maneuver strongly suggests iatrogenic entrapment or laceration of the nerve in the fracture site. This is an absolute indication for immediate surgical exploration and fracture fixation.

Question 11235

Topic: 2. Trauma

A 42-year-old cyclist falls and sustains a 'floating shoulder' consisting of ipsilateral displaced fractures of the midshaft clavicle and the surgical neck of the scapula. Which of the following factors represents the primary indication for operative fixation of this combined injury pattern?

. Any degree of displacement of the clavicular shaft fracture
. Greater than 1 cm medial translation or >40 degrees angulation of the glenoid/scapular neck fragment
. The presence of two or more ipsilateral rib fractures
. Concomitant rupture of the coracoclavicular ligaments
. A non-displaced fracture of the acromion process

Correct Answer & Explanation

. Any degree of displacement of the clavicular shaft fracture

Explanation

A 'floating shoulder' disrupts the superior shoulder suspensory complex. However, not all require surgery. The primary indication for operative intervention (usually fixation of the clavicle, sometimes both) is significant displacement of the scapular neck/glenoid. Specifically, medial translation > 1 cm, angular deformity > 40 degrees, or double disruption of the superior shoulder suspensory complex with profound instability. Fixation of the clavicle alone often indirectly reduces and stabilizes the scapular neck.

Question 11236

Topic: 2. Trauma

A 25-year-old male is involved in a motorcycle collision.

A CT scan reveals a coronal plane fracture of the lateral femoral condyle. What is the standard operative fixation principle for this specific intra-articular fragment?

. Nonoperative management in a long leg cast
. Excision of the fragment and advancement of the lateral collateral ligament
. Fixation utilizing anterior-to-posterior (or posterior-to-anterior) oriented interfragmentary lag screws
. Fixation utilizing standard lateral-to-medial locking screws through a lateral plate
. Tension band wiring using K-wires and figure-of-8 wire

Correct Answer & Explanation

. Nonoperative management in a long leg cast

Explanation

A coronal plane fracture of the femoral condyle is known as a Hoffa fracture (typically type 33-B3 in the AO classification). Because the fracture line runs in the coronal plane (separating anterior from posterior), standard lateral-to-medial screw fixation will be parallel to the fracture line and fail to provide compression. The correct biomechanical fixation principle requires interfragmentary lag screws placed in an anterior-to-posterior (or posterior-to-anterior) direction, perpendicular to the fracture line.

Question 11237

Topic: Pelvic & Acetabular Trauma
In a Young-Burgess Anteroposterior Compression (APC) Type III pelvic ring injury, the mechanism involves severe external rotation of the hemipelvis. Which of the following ligamentous complexes are completely disrupted, distinguishing it from an APC II injury and resulting in complete global (rotational and vertical) instability?
. Anterior sacroiliac, sacrospinous, and sacrotuberous ligaments only
. Posterior sacroiliac ligaments only
. Anterior sacroiliac, posterior sacroiliac, sacrospinous, and sacrotuberous ligaments
. Iliolumbar and posterior sacroiliac ligaments only
. Symphyseal ligaments only

Correct Answer & Explanation

. Anterior sacroiliac, posterior sacroiliac, sacrospinous, and sacrotuberous ligaments

Explanation

In the Young-Burgess classification, APC injuries occur in a sequential cascade. APC I involves symphyseal diastasis < 2.5 cm. APC II involves symphyseal widening > 2.5 cm with tearing of the anterior SI ligaments, sacrospinous, and sacrotuberous ligaments, causing rotational instability but maintaining vertical stability because the posterior SI ligaments remain intact. An APC III injury implies complete disruption of both the anterior AND posterior SI ligaments (along with the pelvic floor ligaments), leading to complete spinopelvic dissociation and both rotational and vertical instability.

Question 11238

Topic: 2. Trauma

A 65-year-old female on prolonged bisphosphonate therapy presents with a displaced atypical femoral fracture (AFF). Radiographs demonstrate marked anterolateral bowing of the femur. During cephalomedullary nailing of this fracture, which technical complication is most likely to occur due to the mismatch between the implant and the patient's altered anatomy?

. Iatrogenic coronal plane fracture of the distal femoral condyles
. Iatrogenic fracture or perforation of the anterior cortex of the distal femur during nail insertion
. Severe rotational malalignment exceeding 30 degrees
. Inability to pass the reamer guidewire past the lesser trochanter
. Atrophic nonunion secondary to excessive thermal necrosis from over-reaming

Correct Answer & Explanation

. Iatrogenic coronal plane fracture of the distal femoral condyles

Explanation

Patients with atypical femur fractures (AFFs) due to prolonged bisphosphonate use often exhibit exaggerated anterolateral bowing of the femur. Standard intramedullary nails are relatively straight compared to this geometry. When a straight, rigid nail is driven into a bowed femur, the tip of the nail impinges on the anterior cortex distally, frequently leading to an iatrogenic perforation or fracture of the anterior cortex. To prevent this, surgeons must carefully match the nail's radius of curvature, use a shorter nail, over-ream, or perform a correcting osteotomy.

Question 11239

Topic: 2. Trauma

A 2-day-old infant presents with decreased movement of the left arm following a difficult vaginal delivery. Examination reveals a palpable mass and crepitus over the middle third of the left clavicle. The Moro reflex is asymmetric. What is the most appropriate management?

. Open reduction and internal fixation
. Figure-of-eight brace application
. Pinning the infant's sleeve to the shirt across the chest
. Immediate referral for brachial plexus exploration
. Skeletal traction

Correct Answer & Explanation

. Open reduction and internal fixation

Explanation

Neonatal clavicle fractures are the most common obstetrical fractures. They are benign and heal rapidly with minimal intervention, typically requiring only supportive care such as pinning the sleeve to the shirt to minimize arm movement and reduce pain.

Question 11240

Topic: 2. Trauma

A 28-year-old polytrauma patient with a bilateral femur fracture and pulmonary contusion is evaluated for surgery. Which of the following laboratory values is an established threshold indicating a 'borderline' or 'unstable' patient, favoring Damage Control Orthopedics (DCO) over Early Total Care (ETC)?

. Lactate 1.5 mmol/L
. Arterial pH 7.35
. Base deficit > 6 mmol/L
. Platelet count 150,000/mm3
. Temperature 36.5ยฐC

Correct Answer & Explanation

. Lactate 1.5 mmol/L

Explanation

A base deficit > 6 mmol/L, lactate > 2.5 mmol/L, pH < 7.24, and platelets < 90,000/mm3 are physiologic indicators of a borderline or unstable patient. These derangements suggest the patient is not adequately resuscitated, favoring DCO to avoid the 'second hit' of prolonged surgery.

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