Menu

2. Trauma MCQs

Practice Set 249 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 4961

Topic: 2. Trauma

A 28-year-old male sustains severe bilateral 'floating knee' injuries (femur and tibia fractures) in an industrial crush accident. He arrives at the trauma center intubated and requires massive transfusion. Which of the following physiologic parameters is the strongest indication to abandon Early Total Care (ETC) and instead pursue Damage Control Orthopedics (DCO) with temporary external fixation?

. Serum lactate of 1.5 mmol/L
. Base deficit of +2 mEq/L
. Arterial pH of 7.20
. Core body temperature of 36.0°C
. Systolic blood pressure > 100 mmHg responsive to 1L crystalloid

Correct Answer & Explanation

. Arterial pH of 7.20

Explanation

Damage Control Orthopedics (DCO) is indicated in physiologically 'unstable' or 'in extremis' polytrauma patients to avoid the 'second hit' phenomenon associated with prolonged definitive surgery (like IM nailing). Established biochemical and physiologic criteria mandating DCO include: arterial pH < 7.24, core temperature < 34.0°C, serum lactate > 2.5 mmol/L (often > 4.0 mmol/L in severe shock), base deficit > 6 mEq/L, and hemodynamic instability requiring ongoing vasopressors.

Question 4962

Topic: Pelvic & Acetabular Trauma
A 35-year-old male is brought to the trauma bay after a high-speed motorcycle crash. His blood pressure is 70/40 mmHg and heart rate is 130 bpm. An AP pelvis radiograph demonstrates an APC-III pelvic ring injury. A FAST scan is negative. A pelvic binder is appropriately applied, but he remains hemodynamically unstable despite receiving 2 units of packed RBCs and plasma. What is the most appropriate next step in management?
. CT scan of the abdomen and pelvis with IV contrast
. Emergent exploratory laparotomy
. Preperitoneal pelvic packing and/or pelvic angiography
. Application of an external fixator in the Emergency Department
. Bilateral internal iliac artery ligation

Correct Answer & Explanation

. Preperitoneal pelvic packing and/or pelvic angiography

Explanation

In a hemodynamically unstable patient with a mechanically unstable pelvic ring injury and a negative FAST scan (ruling out massive intra-abdominal hemorrhage), the bleeding is primarily venous or from pelvic arterial sources. Preperitoneal pelvic packing (PPP) and/or pelvic angiography with embolization are the treatments of choice after initial resuscitation and mechanical stabilization (binder).

Question 4963

Topic: 2. Trauma

A 28-year-old female sustains a Hawkins Type II talar neck fracture following a fall from height. At 8 weeks post-injury, a radiograph of the ankle reveals a band of subchondral radiolucency within the talar dome. What does this specific radiographic finding indicate?

. Osteonecrosis of the talar body
. Impending nonunion of the talar neck
. Hyperemia and an intact blood supply
. Deep infection of the talar dome
. Chondrolysis of the tibiotalar joint

Correct Answer & Explanation

. Hyperemia and an intact blood supply

Explanation

This finding describes the 'Hawkins sign', which is a subchondral radiolucent band in the talar dome visible 6 to 8 weeks after a talar neck fracture. It is a sign of subchondral osteopenia secondary to hyperemia. The presence of the Hawkins sign is a highly reliable indicator that the talar body has an intact vascular supply and that avascular necrosis (AVN) is unlikely to occur.

Question 4964

Topic: 2. Trauma

Historically, the anterior circumflex humeral artery was considered the primary blood supply to the humeral head. Based on current quantitative anatomical studies, which of the following structures provides the predominant arterial supply to the humeral head, and what is its path?

. Anterior circumflex humeral artery entering via the bicipital groove
. Anterior circumflex humeral artery entering via the bare area
. Posterior circumflex humeral artery entering via the bicipital groove
. Posterior circumflex humeral artery entering via the posteromedial aspect of the surgical neck
. Suprascapular artery entering via the rotator interval

Correct Answer & Explanation

. Posterior circumflex humeral artery entering via the posteromedial aspect of the surgical neck

Explanation

Recent highly definitive anatomical and vascular injection studies (e.g., Hettrich et al.) demonstrated that the posterior circumflex humeral artery (PCHA) provides the predominant blood supply (up to 64%) to the humeral head. It enters the proximal humerus along the posteromedial aspect of the surgical neck, making it highly vulnerable in proximal humerus fractures.

Question 4965

Topic: 2. Trauma

A 42-year-old male sustains a pelvic fracture in a motor vehicle collision. CT imaging of the acetabulum reveals a comminuted fracture involving the anterior column and anterior wall. A fracture line also extends across the quadrilateral plate dividing the innominate bone into two halves, with the posterior column detached from the axial skeleton. The posterior column is in a single piece and not comminuted. What is the correct Letournel classification?

. T-type fracture
. Transverse fracture
. Anterior column posterior hemitransverse fracture
. Associated both column fracture
. Transverse with posterior wall fracture

Correct Answer & Explanation

. Associated both column fracture

Explanation

An Associated Both Column fracture is characterized by detachment of all articular segments from the intact axial skeleton. The presence of an anterior column fracture (with or without anterior wall) and a detached posterior column where no part of the articular surface remains attached to the intact ilium defines this pattern. A pathognomonic sign on the obturator oblique radiograph is the 'spur sign'.

Question 4966

Topic: 2. Trauma

A 45-year-old skier sustains a hyperflexion and varus stress injury to the knee. CT imaging shows a displaced coronal shear fracture of the posteromedial tibial plateau. Which of the following describes the most appropriate surgical approach and fixation strategy for this specific fragment?

. Anteromedial approach with an anterior-to-posterior lag screw
. Posteromedial approach with a posterior anti-glide buttress plate
. Lateral approach with a locking plate spanning medially
. Dual anterolateral and anteromedial approaches with orthogonal plating
. Posterolateral approach with fibular head osteotomy

Correct Answer & Explanation

. Posteromedial approach with a posterior anti-glide buttress plate

Explanation

A posteromedial shear fracture of the tibial plateau (often seen as a variant in Schatzker IV or bicondylar injuries) requires a posteromedial approach. To effectively neutralize the vertical shear forces, a posterior buttress plate (anti-glide technique) placed directly on the posterior aspect of the medial plateau is required. Anteromedial plates cannot adequately compress or buttress a posteromedial coronal split.

Question 4967

Topic: 2. Trauma

A 30-year-old male undergoes a 4-compartment fasciotomy for acute compartment syndrome of the leg following a tibial shaft fracture. Which of the following neurovascular structures is contained within the deep posterior compartment of the leg?

. Superficial peroneal nerve
. Tibial nerve and posterior tibial artery
. Sural nerve and short saphenous vein
. Deep peroneal nerve and anterior tibial artery
. Peroneal artery and superficial peroneal nerve

Correct Answer & Explanation

. Tibial nerve and posterior tibial artery

Explanation

The deep posterior compartment of the lower leg contains the deep flexor muscles (tibialis posterior, flexor hallucis longus, flexor digitorum longus), the posterior tibial artery and vein, the peroneal artery and vein, and the tibial nerve. Failure to adequately decompress this compartment can lead to ischemic contractures (e.g., claw toes) and tibial neuropathy.

Question 4968

Topic: Upper Extremity Trauma
A 25-year-old male falls onto his shoulder apex, sustaining a Type III acromioclavicular (AC) joint dislocation. He is curious about the ruptured ligaments. Which of the following statements correctly pairs the coracoclavicular (CC) ligament bundles with their primary biomechanical restraint function?
. The conoid ligament primarily resists horizontal (anterior-posterior) translation
. The trapezoid ligament primarily resists superior translation of the clavicle
. The conoid ligament primarily resists superior translation of the clavicle
. The coracoacromial ligament primarily resists superior translation of the clavicle
. The acromioclavicular ligaments primarily resist superior translation of the clavicle

Correct Answer & Explanation

. The conoid ligament primarily resists superior translation of the clavicle

Explanation

The CC ligaments consist of the medial conoid and the lateral trapezoid. Biomechanical studies have shown that the conoid ligament is the primary restraint against superior translation of the clavicle. The trapezoid ligament primarily resists axial compression (horizontal loading) into the acromion. The AC ligaments provide primary restraint to anterior-posterior translation.

Question 4969

Topic: 2. Trauma

In a polytrauma patient with bilateral femur fractures, establishing the endpoint of resuscitation is critical prior to converting from a damage control external fixator to definitive intramedullary nailing. Which of the following laboratory parameters is the most reliable, validated indicator of adequate tissue perfusion?

. Serum lactate < 2.5 mmol/L
. Base deficit > 8
. Systolic blood pressure > 90 mmHg for 2 hours
. Urine output > 0.5 mL/kg/hr for 1 hour
. Hemoglobin > 10 g/dL

Correct Answer & Explanation

. Serum lactate < 2.5 mmol/L

Explanation

Normalization of serum lactate (typically < 2.5 mmol/L) and correction of the base deficit (approaching 0, generally > -2) are the most sensitive and validated indicators of adequate end-organ tissue perfusion. Clinical parameters like blood pressure and urine output can normalize while an occult 'oxygen debt' still exists at the tissue level, predisposing the patient to acute respiratory distress syndrome (ARDS) or multi-organ failure if subjected to major definitive surgery.

Question 4970

Topic: Upper Extremity Trauma

A 28-year-old professional motocross rider sustains a Type V acromioclavicular (AC) joint dislocation. He undergoes surgical reconstruction of the coracoclavicular (CC) ligaments. Which of the following accurately describes the native anatomy and biomechanics of the CC ligaments being reconstructed?

. The conoid ligament is lateral to the trapezoid ligament and provides primary restraint against anterior translation.
. The trapezoid ligament is medial to the conoid ligament and provides primary restraint against posterior translation.
. The conoid ligament attaches to the posteromedial clavicle and is the primary restraint to superior clavicular translation.
. The trapezoid ligament attaches to the posteromedial clavicle and is the primary restraint to superior clavicular translation.
. Both ligaments insert on the anterior aspect of the clavicle and act equally to resist inferior translation.

Correct Answer & Explanation

. The conoid ligament attaches to the posteromedial clavicle and is the primary restraint to superior clavicular translation.

Explanation

The coracoclavicular (CC) ligament complex consists of the conoid and trapezoid ligaments. The conoid ligament is located medial and posterior to the trapezoid ligament. It is cone-shaped and acts as the primary restraint against superior translation of the clavicle relative to the acromion. The trapezoid ligament is located anterolateral to the conoid and is the primary restraint against axial compression (driving the acromion medial towards the clavicle).

Question 4971

Topic: 2. Trauma

A 45-year-old man is involved in a high-speed motor vehicle collision. Pelvic radiographs and a CT scan reveal an acetabular fracture with a 'spur sign' present on the obturator oblique radiograph. The entire articular surface is detached from the intact axial skeleton. What is the correct Letournel classification for this fracture?

. Anterior column with posterior hemitransverse
. Transverse
. T-type
. Associated both column
. Posterior column with posterior wall

Correct Answer & Explanation

. Associated both column

Explanation

The 'spur sign' on an obturator oblique radiograph is the pathognomonic finding for an associated both column acetabular fracture. It represents the intact portion of the ilium that remains attached to the axial skeleton while the entire articular surface (both columns) is completely dissociated from the intact ilium. No portion of the articular surface remains attached to the axial skeleton in a both column fracture.

Question 4972

Topic: 2. Trauma

A 34-year-old woman sustains a high-energy distal femur fracture. CT scan reveals a coronal plane fracture of the lateral femoral condyle. Which of the following surgical approaches and fixation strategies is most appropriate for addressing this specific fragment?

. Medial parapatellar approach with anterior-to-posterior lag screws
. Medial parapatellar approach with posterior-to-anterior lag screws
. Lateral parapatellar approach with anterior-to-posterior lag screws
. Lateral parapatellar approach with posterior-to-anterior lag screws
. Subvastus approach with a medial laterally directed buttress plate

Correct Answer & Explanation

. Lateral parapatellar approach with anterior-to-posterior lag screws

Explanation

The patient has a Hoffa fracture (coronal plane fracture of the femoral condyle), most commonly involving the lateral condyle. An anterior-to-posterior screw trajectory, placed perpendicular to the fracture plane via a lateral parapatellar approach (often countersunk within the articular cartilage or placed just proximal to it if the fragment size allows), provides the most biomechanically sound lag compression for a lateral Hoffa fracture.

Question 4973

Topic: 2. Trauma

In evaluating a 4-part proximal humerus fracture for the risk of avascular necrosis (AVN) of the humeral head, which of the following radiographic findings is considered the most reliable predictor of subsequent ischemia according to Hertel's criteria?

. Angulation of the articular segment greater than 20 degrees
. Displacement of the tuberosities greater than 5 mm
. A metaphyseal head extension (calcar length) of less than 8 mm attached to the articular segment
. Medial hinge displacement of less than 2 mm
. Comminution of the greater tuberosity

Correct Answer & Explanation

. A metaphyseal head extension (calcar length) of less than 8 mm attached to the articular segment

Explanation

According to Hertel's classic criteria, the most reliable predictors of ischemia (and subsequent AVN) in proximal humerus fractures include a posteromedial metaphyseal head extension (calcar segment) of less than 8 mm, disruption of the medial hinge (>2 mm of displacement), and anatomic neck fracture patterns. A short calcar length attached to the articular segment means the ascending branch of the anterior humeral circumflex artery and endosteal supply are compromised.

Question 4974

Topic: Pelvic & Acetabular Trauma
A 50-year-old pedestrian is struck from the side by a car. Pelvic radiographs show a transverse fracture of the pubic rami and a posterior iliac wing fracture that extends into the sacroiliac joint. What is the Young-Burgess classification of this injury, and what is the primary deforming force?
. Lateral Compression Type I; internal rotation
. Lateral Compression Type II; internal rotation
. Lateral Compression Type III; external rotation
. Anteroposterior Compression Type II; external rotation
. Vertical Shear; superior translation

Correct Answer & Explanation

. Lateral Compression Type II; internal rotation

Explanation

This is a Lateral Compression Type II (LC-II) pelvic ring injury. It is characterized by an anterior ring injury (e.g., transverse pubic rami fractures) combined with a crescent fracture of the posterior ilium extending into the SI joint. The primary deforming force in lateral compression injuries is internal rotation of the hemipelvis.

Question 4975

Topic: 2. Trauma
A 35-year-old farmer sustains an open tibial shaft fracture after his leg is caught in a tractor mechanism. The wound is 12 cm long with significant periosteal stripping, but adequate soft tissue coverage is possible. According to the most recent evidence-based guidelines for severe agricultural open fractures, which empiric antibiotic regimen should be initiated upon arrival to the emergency department?
. Cefazolin monotherapy
. Cefazolin and Gentamicin
. Cefazolin, Gentamicin, and Penicillin
. Ceftriaxone and Metronidazole
. Vancomycin and Piperacillin-Tazobactam

Correct Answer & Explanation

. Cefazolin, Gentamicin, and Penicillin

Explanation

For severe open fractures (Gustilo-Anderson Type III) sustained in an agricultural setting or highly contaminated with soil, standard guidelines recommend an expanded spectrum of coverage. This typically includes a first-generation cephalosporin (Cefazolin) for Gram-positive coverage, an aminoglycoside (Gentamicin) for Gram-negative coverage, and high-dose Penicillin to cover anaerobic organisms, specifically Clostridium perfringens, which can cause gas gangrene.

Question 4976

Topic: 2. Trauma

A 21-year-old male cyclist falls and sustains a midshaft clavicle fracture. Which of the following radiographic or clinical criteria is considered the strongest relative indication for operative fixation to decrease the risk of symptomatic nonunion?

. Fracture displacement greater than 100% with more than 2 cm of shortening
. Superior displacement of the lateral fragment
. Presence of a small butterfly fragment
. Associated mild acromioclavicular sprain
. Age less than 25 years

Correct Answer & Explanation

. Fracture displacement greater than 100% with more than 2 cm of shortening

Explanation

Significant displacement (>100% translation) and shortening (>2 cm) are the strongest predictors of nonunion and poor functional outcomes in midshaft clavicle fractures. Operative fixation in this setting significantly decreases the nonunion rate and improves early functional outcomes compared to non-operative management.

Question 4977

Topic: 2. Trauma
A 29-year-old male sustains a high-energy, vertically oriented femoral neck fracture (Pauwels Type III). He undergoes closed reduction and internal fixation. Which of the following construct modifications would best resist the high shear forces inherent to this fracture pattern?
. Placing the screws in an inverted triangle configuration
. Using fully threaded screws instead of partially threaded screws
. Adding a medial calcar buttress plate
. Adding a transverse fully threaded screw inferior to the primary construct
. Replacing the cannulated screws with a sliding hip screw (SHS) and a derotational screw

Correct Answer & Explanation

. Replacing the cannulated screws with a sliding hip screw (SHS) and a derotational screw

Explanation

Pauwels Type III fractures (>50 degrees) are highly vertically oriented, resulting in immense shear forces that often lead to varus collapse, nonunion, and failure of multiple cannulated screw constructs. Biomechanical studies demonstrate that a fixed-angle device, such as a sliding hip screw (SHS) combined with a derotational screw, provides vastly superior resistance to shear forces and varus collapse compared to three cannulated screws.

Question 4978

Topic: 2. Trauma

A 27-year-old male develops impending compartment syndrome of the lower leg after a tibial shaft fracture. You plan a four-compartment fasciotomy. Which of the following muscle combinations is located entirely within the deep posterior compartment?

. Gastrocnemius, soleus, and plantaris
. Tibialis posterior, flexor digitorum longus, and flexor hallucis longus
. Tibialis anterior, extensor hallucis longus, and extensor digitorum longus
. Peroneus longus and peroneus brevis
. Popliteus, plantaris, and soleus

Correct Answer & Explanation

. Tibialis posterior, flexor digitorum longus, and flexor hallucis longus

Explanation

The deep posterior compartment of the leg contains the tibialis posterior, flexor digitorum longus (FDL), flexor hallucis longus (FHL), and the popliteus (proximally). It also houses the tibial nerve and the posterior tibial and peroneal vessels. Failure to adequately release this specific compartment is a common cause of poor outcomes in leg fasciotomies.

Question 4979

Topic: 2. Trauma
A 25-year-old male sustains a Pauwels Type III (vertical) femoral neck fracture. Which of the following internal fixation constructs provides the greatest biomechanical stability against the high vertical shear forces inherent to this fracture pattern?
. Three parallel cannulated cancellous screws in an inverted triangle configuration
. Two parallel cannulated cancellous screws
. A dynamic condylar screw (DCS) plate
. A fixed-angle sliding hip screw (SHS) with an adjunctive anti-rotation screw
. A cephalomedullary nail locked dynamically

Correct Answer & Explanation

. A fixed-angle sliding hip screw (SHS) with an adjunctive anti-rotation screw

Explanation

Pauwels Type III fractures (>50 degrees) are inherently unstable due to high vertical shear forces. Biomechanical studies consistently demonstrate that fixed-angle devices, such as a sliding hip screw (SHS), combined with a derotational screw to control rotational forces, provide superior stability and higher load-to-failure compared to multiple parallel cannulated screws for vertical femoral neck fractures in young adults.

Question 4980

Topic: 2. Trauma

A 42-year-old female sustains a high-energy Schatzker IV tibial plateau fracture involving a large posteromedial fragment. The surgeon plans a direct posteromedial approach for optimal buttress plating. This approach utilizes an internervous/intermuscular plane between which two structures?

. Lateral head of the gastrocnemius and soleus
. Medial head of the gastrocnemius and the pes anserinus
. Tibialis anterior and extensor hallucis longus
. Peroneus longus and soleus
. Semitendinosus and semimembranosus

Correct Answer & Explanation

. Medial head of the gastrocnemius and the pes anserinus

Explanation

The posteromedial approach to the tibial plateau is indicated for coronal plane fractures with a posteromedial fragment. The superficial dissection involves utilizing the interval between the medial head of the gastrocnemius (retracted laterally/posteriorly) and the pes anserinus (retracted medially/anteriorly). This exposes the popliteus, which can be partially elevated to safely access the posteromedial plateau.

Test Yourself

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

On this Page