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2. Trauma MCQs

Practice Set 522 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 10421

Topic: Lower Extremity Trauma

A 42-year-old male is undergoing open reduction and internal fixation of a bicondylar tibial plateau fracture (Schatzker VI). The surgeon plans a standard posteromedial approach to directly reduce and buttress a displaced posteromedial fragment. The surgical interval for this approach involves mobilizing and retracting which two structures?

. Medial head of the gastrocnemius and the pes anserinus
. Semimembranosus and the medial head of the gastrocnemius
. Tibialis posterior and the flexor digitorum longus
. Medial head of the gastrocnemius and the soleus
. Tibialis anterior and the extensor hallucis longus

Correct Answer & Explanation

. Medial head of the gastrocnemius and the pes anserinus

Explanation

The standard posteromedial approach to the proximal tibia exploits the interval between the medial head of the gastrocnemius (which is retracted posteriorly/laterally to protect the neurovascular bundle) and the pes anserinus tendons (which are retracted anteriorly/medially). This provides excellent exposure of the posteromedial tibial plateau.

Question 10422

Topic: 2. Trauma
A 30-year-old male sustains a Gustilo-Anderson IIIB open fracture of the middle third of the tibia with a 6 cm anterior soft tissue defect exposing bone void of periosteum. Following thorough serial debridement and skeletal stabilization, which of the following is the most appropriate local muscle flap for coverage of this specific defect?
. Gastrocnemius rotational flap
. Soleus rotational flap
. Sural artery fasciocutaneous flap
. Reverse flow sural flap
. Gracilis free flap

Correct Answer & Explanation

. Soleus rotational flap

Explanation

Soft tissue coverage for the tibia is classically divided into thirds. The proximal third is typically covered by a gastrocnemius rotational flap. The middle third is classically covered by a soleus rotational flap. Defects in the distal third of the tibia generally lack adequate local muscle bulk and require free tissue transfer (e.g., gracilis, latissimus dorsi, or ALT flap).

Question 10423

Topic: 2. Trauma

A 45-year-old male is involved in a motor vehicle collision and sustains a complex acetabular fracture.

On the obturator oblique radiograph, the 'spur sign' is distinctly visible. According to the Letournel and Judet classification, this radiographic finding is pathognomonic for which of the following acetabular fracture patterns?

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

Correct Answer & Explanation

. T-type

Explanation

The 'spur sign' is a pathognomonic radiographic feature of an associated both column acetabular fracture. It is best seen on the obturator oblique view and represents the intact portion of the ilium (the strut attached to the sacroiliac joint) protruding outward as the articular segments (both columns) are medially and internally displaced.

Question 10424

Topic: 2. Trauma

A 25-year-old snowboarder sustains a Hawkins type II talar neck fracture and undergoes urgent ORIF. At 8 weeks postoperatively, an AP radiograph of the ankle demonstrates a subchondral radiolucent band in the talar dome, known as the Hawkins sign. What is the clinical significance of this finding?

. It represents impending avascular necrosis of the talar body
. It indicates intact vascularity to the talar body
. It is a reliable sign of talar neck nonunion
. It signifies the early onset of post-traumatic subtalar arthritis
. It is pathognomonic for deep infection of the talar dome

Correct Answer & Explanation

. It represents impending avascular necrosis of the talar body

Explanation

The Hawkins sign is a subchondral radiolucent band seen in the talar dome, typically appearing 6 to 8 weeks after a talar neck fracture. It is a sign of subchondral osteopenia, which can only occur if there is active bone resorption. Active bone resorption requires an intact blood supply; thus, the presence of the Hawkins sign is a reassuring indicator that the talar body retains its vascularity and is unlikely to develop avascular necrosis.

Question 10425

Topic: 2. Trauma

The standard of care for high-energy tibial pilon fractures usually involves temporary application of a spanning external fixator followed by delayed definitive ORIF 10-14 days later. What is the primary rationale for staging the surgical management of this injury?

. To allow for consolidation of cancellous metaphyseal bone, making screw purchase more reliable
. To allow the soft tissue envelope to recover, decreasing the risk of deep wound infection and wound breakdown
. To facilitate complete evaluation of cartilage damage via outpatient MRI
. To allow the fracture to become partially sticky for easier reduction
. To inherently decrease the long-term incidence of post-traumatic arthritis

Correct Answer & Explanation

. To allow for consolidation of cancellous metaphyseal bone, making screw purchase more reliable

Explanation

High-energy pilon fractures are associated with severe soft tissue trauma. Early definitive internal fixation through compromised soft tissue carries an unacceptably high risk of wound breakdown, dehiscence, and deep infection. Staged management with a spanning external fixator provides skeletal stability while allowing the soft tissue swelling to subside (the 'wrinkle sign'), significantly lowering complication rates.

Question 10426

Topic: 2. Trauma

A 22-year-old male sustains a closed, distal-third spiral humeral shaft fracture (Holstein-Lewis) during an arm-wrestling match. On initial presentation, he exhibits a dense radial nerve palsy. Closed reduction is performed and a coaptation splint is applied. Post-reduction examination confirms the radial nerve palsy is persistent and unchanged. Based on AAOS guidelines, what is the most appropriate management of the radial nerve?

. Immediate surgical exploration of the radial nerve
. Immediate EMG and nerve conduction studies
. Observation and clinical re-evaluation in 3-4 months
. Immediate acute tendon transfers for wrist extension
. Urgent MRI of the humerus to visualize nerve entrapment

Correct Answer & Explanation

. Immediate surgical exploration of the radial nerve

Explanation

For a closed humeral shaft fracture presenting with a primary radial nerve palsy (present before any manipulation), the most appropriate management is observation. Most radial nerve palsies in this setting are neurapraxias that will spontaneously recover within 3-4 months. Immediate exploration is typically reserved for open fractures, penetrating injuries, or secondary palsies (a palsy that develops strictly after closed reduction, indicating potential entrapment).

Question 10427

Topic: 2. Trauma

A 20-year-old college athlete falls onto an outstretched hand and sustains a fracture of the proximal pole of the scaphoid. This fracture pattern carries a high risk of nonunion and avascular necrosis due to the scaphoid's retrograde blood supply. Which of the following arteries provides the primary blood supply to the proximal pole of the scaphoid?

. Palmar carpal branch of the radial artery
. Dorsal carpal branch of the radial artery
. Superficial palmar arch
. Deep palmar arch
. Anterior interosseous artery

Correct Answer & Explanation

. Palmar carpal branch of the radial artery

Explanation

The scaphoid receives its primary blood supply from the dorsal carpal branch of the radial artery, which enters the scaphoid at the dorsal ridge (distal to the waist) and flows in a retrograde fashion to supply the proximal pole. Consequently, proximal pole fractures disrupt this retrograde blood flow, leading to a high rate of avascular necrosis and nonunion.

Question 10428

Topic: 2. Trauma

A 40-year-old male is involved in a high-speed motor vehicle collision. Radiographs and CT scan of his right knee reveal an intra-articular, coronal plane fracture of the lateral femoral condyle. What is the eponym for this specific fracture pattern, and what is the optimal trajectory for lag screw fixation?

. Barton fracture; Anterior-to-posterior screws
. Hoffa fracture; Anterior-to-posterior screws
. Cedell fracture; Posterior-to-anterior screws
. Hoffa fracture; Proximal-to-distal screws
. Chaput fracture; Lateral-to-medial screws

Correct Answer & Explanation

. Barton fracture; Anterior-to-posterior screws

Explanation

A Hoffa fracture is a coronal plane fracture of the distal femoral condyle, most commonly affecting the lateral condyle. Because it is a coronal fracture, optimal compression across the fracture site is achieved with lag screws placed perpendicular to the fracture line, typically in an anterior-to-posterior (AP) trajectory.

Question 10429

Topic: 2. Trauma
A 28-year-old male sustains a closed comminuted midshaft tibia fracture. Eight hours later, he complains of worsening pain out of proportion to the injury, unrelieved by intravenous opioids. His blood pressure is 110/70 mmHg. Intracompartmental pressure testing of the anterior compartment yields a measurement of 45 mmHg. What is the patient's Delta P (ΔP), and what is the indicated treatment?
. 25 mmHg; Immediate four-compartment fasciotomy
. 45 mmHg; Immediate four-compartment fasciotomy
. 65 mmHg; Observation and elevation
. 25 mmHg; Observation and elevation
. 40 mmHg; Immediate four-compartment fasciotomy

Correct Answer & Explanation

. 25 mmHg; Immediate four-compartment fasciotomy

Explanation

Acute compartment syndrome is diagnosed clinically, but compartment pressures can be used adjunctively. Delta P (ΔP) is calculated as the diastolic blood pressure minus the compartment pressure (70 - 45 = 25 mmHg). A ΔP of less than 30 mmHg is the accepted threshold indicating inadequate tissue perfusion and is a strict indication for an emergent four-compartment fasciotomy of the leg.

Question 10430

Topic: 2. Trauma

The Mangled Extremity Severity Score (MESS) is a clinical tool historically utilized to help guide the difficult decision between amputation and limb salvage in severe lower extremity trauma. Which of the following variables is NOT a scored component of the MESS criteria?

. Patient age
. Limb ischemia time
. Shock (hemodynamic instability)
. Skeletal and soft-tissue injury severity
. Presence of associated head injury

Correct Answer & Explanation

. Patient age

Explanation

The Mangled Extremity Severity Score (MESS) consists of four variables: 1) Skeletal and soft-tissue injury (energy level), 2) Limb ischemia (degree and duration), 3) Shock (systolic blood pressure), and 4) Patient age. The presence of an associated head injury is not a component of the MESS.

Question 10431

Topic: 2. Trauma

A 35-year-old male polytrauma patient presents with closed bilateral femoral shaft fractures, multiple rib fractures, and bilateral pulmonary contusions. Initial arterial blood gas evaluation shows a pH of 7.21, base excess of -8, and lactate of 5.0 mmol/L. According to the principles of Damage Control Orthopedics (DCO), what is the most appropriate initial management for his femur fractures?

. Bilateral reamed intramedullary nailing within 24 hours
. Unreamed intramedullary nailing of both femurs immediately
. Skeletal traction until pulmonary function normalizes
. Bilateral spanning external fixation of the femurs
. Open reduction and internal fixation with compression plating

Correct Answer & Explanation

. Bilateral reamed intramedullary nailing within 24 hours

Explanation

This patient is a 'borderline' or 'unstable' polytrauma patient based on his significant acidosis (pH 7.21), high lactate (5.0 mmol/L), and concomitant chest trauma (pulmonary contusions). Under the principles of Damage Control Orthopedics (DCO), definitive fixation (such as reamed IM nailing) risks a second hit phenomenon, exacerbating ARDS and multisystem organ failure. The optimal management is rapid provisional stabilization with spanning external fixators, delaying definitive nailing until his physiology normalizes.

Question 10432

Topic: 2. Trauma
A 45-year-old farmer catches his leg in a tractor mechanism, sustaining a Gustilo-Anderson type IIIA open tibia fracture heavily contaminated with soil and manure. According to current evidence-based guidelines for open fracture management in farm injuries, which of the following intravenous antibiotic regimens is most traditionally appropriate for initial prophylaxis?
. First-generation cephalosporin alone
. First-generation cephalosporin and an aminoglycoside
. Third-generation cephalosporin alone
. First-generation cephalosporin, an aminoglycoside, and high-dose penicillin
. Fluoroquinolone alone

Correct Answer & Explanation

. First-generation cephalosporin, an aminoglycoside, and high-dose penicillin

Explanation

For severe open fractures (Gustilo Type III), the standard antibiotic regimen historically includes a first-generation cephalosporin (for Gram-positive coverage) and an aminoglycoside (for Gram-negative coverage). If there is gross organic contamination (e.g., farm injury, soil, manure), high-dose penicillin is added specifically to provide coverage against Clostridium species to prevent gas gangrene.

Question 10433

Topic: 2. Trauma

A 32-year-old competitive cyclist falls directly onto his right shoulder, sustaining a midshaft clavicle fracture. Which of the following radiographic or clinical findings is considered an absolute indication for open reduction and internal fixation rather than nonoperative management?

. 1.5 cm of fracture shortening
. Superior displacement of the proximal fragment by 100%
. Open fracture
. Z-type deformity with comminution
. Presence of an ipsilateral non-displaced scapular body fracture

Correct Answer & Explanation

. 1.5 cm of fracture shortening

Explanation

Absolute indications for operative fixation of a clavicle fracture include open fractures, fractures with associated neurovascular compromise, and severe skin tenting that threatens skin integrity (impending open fracture). While shortening (>2 cm), complete displacement, and Z-deformities are relative indications (particularly in active patients to prevent nonunion or malunion), an open fracture demands operative debridement and fixation.

Question 10434

Topic: 2. Trauma

A 22-year-old male sustains a low-velocity civilian gunshot wound to the right thigh, resulting in a comminuted midshaft femur fracture. The entrance and exit wounds are 1 cm in diameter with no gross contamination or active bleeding. Compartments are soft, and distal pulses are intact. What is the most appropriate management of this injury?

. Formal surgical open debridement of the bullet tract followed by immediate intramedullary nailing
. Local wound care, tetanus prophylaxis, IV antibiotics, and antegrade intramedullary nailing
. Application of a spanning external fixator and delayed intramedullary nailing
. Nonoperative management with skeletal traction for 6 weeks
. Exploration of the femoral artery and vein followed by intramedullary nailing

Correct Answer & Explanation

. Formal surgical open debridement of the bullet tract followed by immediate intramedullary nailing

Explanation

Low-velocity gunshot wounds resulting in extra-articular long bone fractures are generally treated as closed fractures with respect to fixation. They do not require formal open debridement of the bullet tract unless there is gross contamination, suspected vascular injury, compartment syndrome, or intra-articular extension. Standard of care includes local wound care, tetanus, short-course IV antibiotics, and early definitive fixation (e.g., IM nailing).

Question 10435

Topic: Pelvic & Acetabular Trauma
A 28-year-old hypotensive male is brought in after a motorcycle crash. A pelvic binder is immediately applied. Radiographs show a widened symphysis pubis and disrupted sacroiliac joints bilaterally, consistent with an Anteroposterior Compression (APC) Type III injury. FAST scan is negative. Despite 2 units of uncrossmatched blood and crystalloid resuscitation, his blood pressure remains 75/40 mmHg. What is the most appropriate next step in management?
. Exploratory laparotomy
. Pelvic angiography and embolization
. Immediate open reduction and internal fixation of the anterior pelvic ring
. Zone III REBOA placement followed by definitive internal fixation
. Application of a supra-acetabular external fixator and transfer to the ICU

Correct Answer & Explanation

. Pelvic angiography and embolization

Explanation

In a hemodynamically unstable patient with a mechanically unstable pelvic ring injury and no other identified source of major bleeding (negative FAST and chest X-ray), pelvic angiography and embolization is indicated to control arterial hemorrhage. The bleeding is typically from branches of the internal iliac artery, such as the superior gluteal, internal pudendal, or obturator arteries.

Question 10436

Topic: 2. Trauma
A 22-year-old male sustains a vertical, displaced basicervical femoral neck fracture (Pauwels Type III) during a sporting event. Which of the following factors has been shown in recent literature to be the most critical in decreasing the rate of nonunion and osteonecrosis in this specific patient population?
. Time from injury to surgery of less than 6 hours
. Utilization of a sliding hip screw instead of multiple cannulated screws
. Quality of the anatomic reduction of the fracture
. Routine capsulotomy to relieve intracapsular hematoma pressure
. Prophylactic vascularized free fibular grafting

Correct Answer & Explanation

. Quality of the anatomic reduction of the fracture

Explanation

While historically the timing of surgery (under 6 hours) was considered paramount, recent literature heavily emphasizes that the quality of anatomic reduction is the single most important factor in determining the outcome and decreasing nonunion and AVN rates in young adults with displaced femoral neck fractures. Pauwels III fractures have high shear forces, requiring meticulous reduction and stable fixation (e.g., dynamic hip screw with a derotation screw or proximal femoral locking plate).

Question 10437

Topic: 2. Trauma

In the setting of a completely displaced subtrochanteric femur fracture, the proximal fragment is typically displaced into flexion, abduction, and external rotation due to muscular pull. Which muscle group is primarily responsible for the external rotation deformity of the proximal fragment?

. Iliopsoas
. Gluteus medius and minimus
. Short external rotators
. Gluteus maximus
. Adductor longus

Correct Answer & Explanation

. Iliopsoas

Explanation

The short external rotators (piriformis, superior and inferior gemelli, obturator internus and externus, and quadratus femoris) insert on or near the greater trochanter and externally rotate the proximal fragment. The iliopsoas (inserting on the lesser trochanter) causes the flexion deformity. The gluteus medius and minimus (inserting on the greater trochanter) cause the abduction deformity.

Question 10438

Topic: 2. Trauma

A 45-year-old male sustains a high-energy varus injury to his knee, resulting in a medial tibial plateau fracture with a large posteromedial fragment (Schatzker IV). Which of the following surgical approaches is most appropriate for direct visualization and optimal mechanical buttress plating of the posteromedial fragment?

. Anterolateral approach
. Midline transpatellar approach
. Posteromedial approach between the medial gastrocnemius and pes anserinus
. Direct posterior approach through the popliteal fossa
. Medial parapatellar approach

Correct Answer & Explanation

. Anterolateral approach

Explanation

The posteromedial fragment in a Schatzker IV tibial plateau fracture is best addressed via a posteromedial approach. The surgical interval is typically developed between the medial head of the gastrocnemius (retracted laterally and posteriorly) and the pes anserinus tendons (retracted medially and anteriorly). This allows for direct visualization of the fracture apex and the placement of an anti-glide or buttress plate to counteract the vertical shear forces.

Question 10439

Topic: 2. Trauma

A 30-year-old male is admitted with a closed midshaft tibia fracture treated with casting. Twelve hours later, he complains of severe, escalating leg pain out of proportion to the injury, unrelieved by intravenous opioids. On examination, he has pain with passive stretch of the hallux and a tense calf. When utilizing intra-compartmental pressure monitoring, what is the most definitive diagnostic threshold indicating acute compartment syndrome that requires immediate fasciotomy?

. Absolute compartment pressure greater than 20 mmHg
. Absolute compartment pressure greater than 30 mmHg
. Delta pressure (Diastolic Blood Pressure minus Compartment Pressure) less than 30 mmHg
. Delta pressure (Mean Arterial Pressure minus Compartment Pressure) less than 40 mmHg
. Loss of palpable dorsalis pedis and posterior tibial pulses

Correct Answer & Explanation

. Absolute compartment pressure greater than 20 mmHg

Explanation

Acute compartment syndrome is primarily a clinical diagnosis based on the 'Ps' (pain out of proportion, pain with passive stretch, etc.). However, when pressure measurements are used (e.g., in obtunded or polytrauma patients, or equivocal cases), a Delta pressure (Diastolic Blood Pressure minus Compartment Pressure) of less than 30 mmHg is the most reliable and accepted threshold. Loss of pulses is a very late and unreliable sign.

Question 10440

Topic: 2. Trauma

A 42-year-old female presents with a high-energy intra-articular distal tibia fracture (Pilon, AO/OTA 43-C3) with severe soft tissue swelling, fracture blisters, and a significantly shortened extremity. What is the gold standard initial management protocol for this injury?

. Immediate open reduction and internal fixation to perfectly restore articular congruity
. Application of a spanning external fixator and definitive ORIF once soft tissues allow
. Primary arthrodesis of the tibiotalar joint due to the high-energy articular comminution
. Intramedullary nailing with percutaneous screw fixation of the articular surface
. Closed reduction and placement in a long leg cast until swelling subsides

Correct Answer & Explanation

. Immediate open reduction and internal fixation to perfectly restore articular congruity

Explanation

High-energy Pilon fractures are associated with profound soft tissue injury. Early definitive open reduction and internal fixation carries an unacceptably high risk of wound breakdown, deep infection, and osteomyelitis. The standard of care is a two-staged approach: initial application of a joint-spanning external fixator to restore length, alignment, and rotation (Damage Control), followed by definitive ORIF once the soft tissue envelope has healed (typically 10-21 days later, indicated by the 'wrinkle sign' and epithelialization of blisters).

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