Menu

2. Trauma MCQs

Practice Set 280 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 5581

Topic: 2. Trauma

A 68-year-old osteoporotic female sustains a proximal humerus fracture. The AP radiograph is shown.

According to the Hertel criteria, which of the following radiographic features is the most reliable predictor of humeral head ischemia?

. Anatomical neck fracture pattern
. Greater tuberosity displacement > 1 cm
. Metaphyseal head extension (calcar segment) less than 8 mm
. Varus angulation greater than 20 degrees
. Disruption of the medial periosteal hinge > 2 mm

Correct Answer & Explanation

. Metaphyseal head extension (calcar segment) less than 8 mm

Explanation

Hertel et al. described radiographic criteria predictive of humeral head ischemia. The most reliable predictors include a metaphyseal head extension (calcar segment) of less than 8 mm, disruption of the medial hinge (>2 mm), and an anatomic neck fracture. Among the choices, the calcar segment length < 8 mm represents a highly predictive sign that the primary blood supply (the ascending branch of the anterior humeral circumflex artery and intraosseous vessels) has been severely compromised.

Question 5582

Topic: 2. Trauma

A 22-year-old male falls onto an extended wrist and sustains a displaced fracture of the proximal pole of the scaphoid. What anatomical feature dictates the precarious blood supply and high risk of avascular necrosis (AVN) in this specific fracture?

. The proximal pole is supplied exclusively by the anterior interosseous artery.
. Blood supply runs retrograde, with vessels entering the distal half and dorsal ridge before supplying the proximal pole.
. The proximal pole receives its blood supply from a single volar branch of the ulnar artery.
. Blood supply depends entirely on the scapholunate interosseous ligament.
. The scaphoid relies on diffusion from synovial fluid for its entire nutrient supply.

Correct Answer & Explanation

. Blood supply runs retrograde, with vessels entering the distal half and dorsal ridge before supplying the proximal pole.

Explanation

The major blood supply to the scaphoid comes from branches of the radial artery that enter the bone distally, primarily along the dorsal ridge, and flow in a retrograde direction to perfuse the proximal pole. Fractures through the waist or proximal pole disrupt this retrograde flow, leading to a high incidence of nonunion and avascular necrosis of the proximal fragment.

Question 5583

Topic: 2. Trauma

A 5-year-old child falls on an outstretched hand and sustains the elbow injury shown.

The fracture is displaced 4 mm. If left untreated or mismanaged as a simple sprain, what is the most likely long-term clinical complication?

. Cubitus varus and tardy radial nerve palsy
. Cubitus valgus and tardy ulnar nerve palsy
. Myositis ossificans of the brachialis
. Premature closure of the olecranon apophysis
. Volkmann's ischemic contracture

Correct Answer & Explanation

. Cubitus valgus and tardy ulnar nerve palsy

Explanation

The scenario describes a lateral condyle fracture of the pediatric humerus. Because the lateral condyle provides the lateral buttress of the elbow and is intra-articular, nonunion (due to inadequate immobilization or failure to fix a displaced fracture) commonly leads to a progressive cubitus valgus deformity. Over time, the increased carrying angle stretches the ulnar nerve behind the medial epicondyle, resulting in a tardy ulnar nerve palsy.

Question 5584

Topic: 2. Trauma

In the treatment of unstable intertrochanteric femur fractures with a cephalomedullary nail, achieving correct lag screw placement is critical. According to the original study by Baumgaertner et al., what is the ideal tip-apex distance (TAD) recommended to minimize the risk of lag screw cut-out?

. Less than 10 mm
. Less than 15 mm
. Less than 25 mm
. Less than 35 mm
. Greater than 25 mm

Correct Answer & Explanation

. Less than 25 mm

Explanation

Baumgaertner et al. defined the tip-apex distance (TAD) as the sum of the distance from the tip of the lag screw to the apex of the femoral head on both AP and lateral radiographs, after correcting for magnification. A TAD of less than 25 mm was shown to significantly correlate with a minimal risk of lag screw cut-out in the treatment of intertrochanteric fractures.

Question 5585

Topic: Pelvic & Acetabular Trauma
A 35-year-old male is brought into the trauma bay after a high-speed motorcycle crash. His blood pressure is 80/50 mmHg and heart rate is 130 bpm. An AP pelvis radiograph demonstrates an anteroposterior compression (APC) type III pelvic ring fracture. Following the immediate application of a pelvic binder, his blood pressure remains 85/50 mmHg despite administration of 2L of crystalloid and 2 units of uncrossmatched PRBCs. What is the most appropriate next step in management?
. Immediate exploratory laparotomy
. Pre-peritoneal pelvic packing and/or angiography
. Definitive internal fixation of the anterior and posterior pelvic ring
. Removal of the pelvic binder and application of an external fixator
. Placement of an IVC filter

Correct Answer & Explanation

. Pre-peritoneal pelvic packing and/or angiography

Explanation

In hemodynamically unstable patients with pelvic ring injuries, the first step is mechanical stabilization of the pelvic volume (e.g., pelvic binder or sheet). If the patient remains persistently hypotensive despite resuscitation and stabilization, hemorrhage control is required. Institutional protocols vary between pre-peritoneal pelvic packing (to control venous bleeding, which is the most common source) and angiography with embolization (for arterial bleeding). Laparotomy is contraindicated unless there is a clear concurrent intra-abdominal source of bleeding, as it eliminates the tamponade effect.

Question 5586

Topic: 2. Trauma
A 25-year-old female sustains a Pauwels type III femoral neck fracture after a motor vehicle accident. Which biomechanical force makes this specific fracture pattern particularly prone to fixation failure and varus collapse?
. Compression forces
. Shear forces
. Tension forces
. Torsional forces
. Bending forces

Correct Answer & Explanation

. Shear forces

Explanation

The Pauwels classification of femoral neck fractures is based on the angle of the fracture line relative to the horizontal. A Pauwels type III fracture is highly vertical (angle >50 degrees). Because of this vertical orientation, normal joint reactive forces across the hip are converted primarily into high shear forces across the fracture line, predisposing the fracture to varus collapse, loss of fixation, and nonunion compared to the more compressive forces seen in horizontal fractures.

Question 5587

Topic: 2. Trauma
A 28-year-old male sustains a high-energy Pauwels type III femoral neck fracture. Compared to a Pauwels type I fracture, which of the following biomechanical forces is most significantly increased at the fracture site?
. Compressive forces
. Shear forces
. Tensile forces
. Rotational forces
. Torsional forces

Correct Answer & Explanation

. Shear forces

Explanation

The Pauwels classification of femoral neck fractures is based on the angle of the fracture line relative to the horizontal plane. A type III fracture has an angle greater than 50 degrees, making it more vertically oriented. This vertical orientation significantly increases shear forces across the fracture site, leading to a higher risk of varus collapse, nonunion, and fixation failure.

Question 5588

Topic: Pelvic & Acetabular Trauma
A 35-year-old male is brought to the trauma bay after a motorcycle accident. A pelvic radiograph shows a completely disrupted pubic symphysis and widened sacroiliac joints bilaterally (APC type III injury). He is hemodynamically unstable. What is the most common anatomical source of life-threatening hemorrhage in this injury pattern?
. Superior gluteal artery
. Presacral venous plexus and cancellous bone
. Internal pudendal artery
. External iliac artery
. Obturator artery

Correct Answer & Explanation

. Presacral venous plexus and cancellous bone

Explanation

While arterial bleeding (commonly from the superior gluteal or internal pudendal arteries) can occur and is often addressed by angioembolization, the vast majority (approximately 80-90%) of life-threatening hemorrhage in blunt pelvic ring injuries arises from the presacral venous plexus and the fractured cancellous bony surfaces. Venous and bony bleeding are primarily managed by reducing pelvic volume (e.g., with a pelvic binder or external fixator).

Question 5589

Topic: 2. Trauma

A 32-year-old male sustains a closed tibia fracture and develops intense leg pain out of proportion to the injury. You suspect acute compartment syndrome.

Which of the following pressure parameters is considered the most reliable threshold indication for performing a four-compartment fasciotomy?

. Absolute compartment pressure > 30 mmHg
. Absolute compartment pressure > 45 mmHg
. Diastolic blood pressure minus compartment pressure (Delta P) < 30 mmHg
. Mean arterial pressure minus compartment pressure (Delta P) < 40 mmHg
. Systolic blood pressure minus compartment pressure (Delta P) < 20 mmHg

Correct Answer & Explanation

. Diastolic blood pressure minus compartment pressure (Delta P) < 30 mmHg

Explanation

The differential pressure (Delta P) is universally recognized as more reliable than absolute compartment pressure for diagnosing acute compartment syndrome. A Delta P is calculated by subtracting the intracompartmental pressure from the patient's diastolic blood pressure. A Delta P of less than 30 mmHg represents inadequate tissue perfusion pressure and is an absolute indication for emergency fasciotomy.

Question 5590

Topic: Lower Extremity Trauma
A 45-year-old man sustains a high-energy knee injury in a motorcycle accident. Based on the Schatzker classification, a bicondylar tibial plateau fracture with complete dissociation of the metaphysis from the diaphysis is classified as:
. Schatzker III
. Schatzker IV
. Schatzker V
. Schatzker VI
. Schatzker II

Correct Answer & Explanation

. Schatzker VI

Explanation

A Schatzker VI fracture is defined by complete metaphyseal-diaphyseal dissociation, often accompanied by severe soft tissue injury. Schatzker V is a bicondylar fracture but maintains continuity between the articular segment and the diaphysis. Schatzker I-III involve the lateral plateau, and IV involves the medial plateau.

Question 5591

Topic: 2. Trauma
A 30-year-old male is admitted after suffering a closed tibial shaft fracture. Twelve hours later, he complains of severe pain out of proportion to his injury and pain with passive toe extension. Which of the following pressure measurements is the most reliable threshold indicating the need for an emergent fasciotomy?
. Absolute compartment pressure of 20 mmHg
. Absolute compartment pressure of 25 mmHg
. Delta pressure (Diastolic blood pressure minus compartment pressure) of less than 30 mmHg
. Delta pressure (Systolic blood pressure minus compartment pressure) of less than 45 mmHg
. Mean arterial pressure minus compartment pressure of less than 30 mmHg

Correct Answer & Explanation

. Delta pressure (Diastolic blood pressure minus compartment pressure) of less than 30 mmHg

Explanation

The delta pressure (Δp) is calculated as the diastolic blood pressure minus the intracompartmental pressure. A Δp of less than 30 mmHg is considered highly specific for acute compartment syndrome and is a standard indication for emergent four-compartment fasciotomy of the leg. Absolute pressures are less reliable because tissue perfusion depends on the perfusion gradient.

Question 5592

Topic: Pelvic & Acetabular Trauma
When applying a circumferential pelvic binder for a hemodynamically unstable APC-III pelvic ring injury, what is the optimal anatomic landmark for placement to maximize reduction and minimize complications?
. Iliac crests
. Anterior superior iliac spines
. Greater trochanters
. Symphysis pubis
. Subtrochanteric line

Correct Answer & Explanation

. Greater trochanters

Explanation

Pelvic binders should be centered directly over the greater trochanters to effectively close the pelvic ring, generate appropriate compressive vectors, and avoid excessive pressure on the abdomen or inadequate reduction seen with higher placements (e.g., over the iliac crests).

Question 5593

Topic: Pelvic & Acetabular Trauma

Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by flowing ossification along the anterolateral aspect of the spine. According to Resnick's classical diagnostic criteria, how many contiguous vertebral bodies must be involved?

. 2
. 3
. 4
. 5
. 6

Correct Answer & Explanation

. 4

Explanation

Resnick's criteria for DISH include: flowing ossification of at least 4 contiguous vertebral bodies (bridging 3 intervertebral disc spaces), preservation of disc height, and the absence of apophyseal joint ankylosis or sacroiliac erosion.

Question 5594

Topic: 2. Trauma
According to current guidelines for a Type III open tibia fracture heavily contaminated with soil from an agricultural farm injury, what is the most appropriate initial empiric systemic antibiotic coverage?
. First-generation cephalosporin alone
. First-generation cephalosporin and an aminoglycoside
. First-generation cephalosporin, an aminoglycoside, and high-dose penicillin
. Fluoroquinolone alone
. Carbapenem monotherapy

Correct Answer & Explanation

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

Explanation

For severe open fractures (Type III) with farm or heavily contaminated soil exposure, high-dose penicillin is added specifically for anaerobic coverage (e.g., Clostridium species) to prevent gas gangrene, along with a 1st-generation cephalosporin (Gram-positive coverage) and an aminoglycoside (Gram-negative coverage).

Question 5595

Topic: 2. Trauma

A 30-year-old male with a comminuted tibial shaft fracture complains of escalating leg pain out of proportion to the injury. His blood pressure is 110/80 mmHg. Intracompartmental pressure testing is performed. Which of the following measured thresholds is the most reliable criterion for performing an emergency fasciotomy?

. Absolute compartment pressure > 20 mmHg
. Absolute compartment pressure > 30 mmHg
. Delta P (Diastolic BP minus Compartment Pressure) < 30 mmHg
. Delta P (Mean Arterial Pressure minus Compartment Pressure) < 40 mmHg
. Delta P (Systolic BP minus Compartment Pressure) < 50 mmHg

Correct Answer & Explanation

. Delta P (Diastolic BP minus Compartment Pressure) < 30 mmHg

Explanation

The Delta P concept (Diastolic Blood Pressure minus Compartment Pressure < 30 mmHg) is the most reliable and universally accepted threshold for diagnosing acute compartment syndrome. It accounts for the perfusion pressure of the limb, reducing unnecessary fasciotomies in hypotensive patients.

Question 5596

Topic: 2. Trauma

An 85-year-old female with severe rheumatoid arthritis and osteoporosis sustains a highly comminuted, intra-articular distal humerus fracture (AO/OTA 13-C3) after a mechanical fall. She lives independently and uses a walker. Which surgical intervention provides the most predictable pain relief and allows for immediate postoperative weight-bearing through the upper extremity for mobility?

. Open reduction and internal fixation with dual orthogonal locking plates
. Hinged external fixation
. Total elbow arthroplasty
. Olecranon osteotomy and tension band wiring
. Distal humerus hemiarthroplasty

Correct Answer & Explanation

. Total elbow arthroplasty

Explanation

In an elderly, osteoporotic patient (especially with a history of inflammatory arthritis like RA) who sustains a highly comminuted intra-articular distal humerus fracture, Total Elbow Arthroplasty (TEA) provides superior outcomes compared to ORIF. It offers more predictable pain relief, earlier return of function, and allows the patient to bear weight immediately (within standard TEA limits, though essential for immediate walker use) without the high risk of hardware failure or nonunion associated with osteoporotic bone.

Question 5597

Topic: Pelvic & Acetabular Trauma
A 35-year-old male is brought to the trauma bay following a high-speed motorcycle collision. He is hemodynamically unstable with a blood pressure of 75/40 mmHg. An anteroposterior pelvic radiograph reveals an APC-III pelvic ring injury (diastasis of the pubic symphysis > 2.5 cm and disruption of the sacroiliac joints). A circumferential pelvic sheet or binder is indicated. To be maximally effective in reducing the pelvic volume and stabilizing the venous plexus, the binder must be centered over which anatomical landmark?
. The anterior superior iliac spines
. The greater trochanters
. The iliac crests
. The umbilicus
. The proximal femur shafts

Correct Answer & Explanation

. The greater trochanters

Explanation

To effectively reduce pelvic volume in open-book (APC) pelvic ring injuries, a pelvic binder or sheet must be centered squarely over the greater trochanters of the femurs. Placement over the iliac crests is a common error that can actually force the pelvis into further outward rotation or fail to adequately close the posterior pelvic ring, exacerbating hemorrhage.

Question 5598

Topic: 2. Trauma

A 25-year-old cyclist goes over his handlebars and lands heavily on his left shoulder. Radiographs confirm a displaced midshaft clavicle fracture. While the decision for surgery often involves shared decision-making, which of the following scenarios is universally considered an absolute, unquestionable indication for immediate open reduction and internal fixation of a clavicle fracture?

. 1.5 cm of overall fracture shortening
. 100% superior displacement of the proximal fragment
. Severe comminution with a z-fragment
. Open fracture with exposed bone
. The patient is a high-demand professional athlete

Correct Answer & Explanation

. Open fracture with exposed bone

Explanation

Absolute indications for operative management of a clavicle fracture include open fractures, fractures with associated progressive neurovascular injury, skin tenting that threatens to necrose and progress to an open fracture, and 'floating shoulder' (ipsilateral displaced clavicle and scapular neck fractures). High degrees of displacement, shortening >2 cm, comminution, and the patient's athletic or occupational demands are considered relative indications for surgery.

Question 5599

Topic: 2. Trauma
A 45-year-old male sustains an anterior-posterior compression (APC) type III pelvic ring injury following a crush injury. He is hemodynamically unstable upon arrival. If an arterial source of bleeding is identified on pelvic angiography, which of the following arteries is most likely to be injured based on the fracture pattern?
. Superior gluteal artery
. Inferior gluteal artery
. Internal pudendal artery
. External iliac artery
. Iliolumbar artery

Correct Answer & Explanation

. Internal pudendal artery

Explanation

In anterior-posterior compression (APC) injuries, the internal pudendal and obturator arteries are the most commonly injured arterial branches due to disruption of the anterior ring. Conversely, in lateral compression injuries and fractures extending through the greater sciatic notch, the superior gluteal artery is the most frequently injured.

Question 5600

Topic: 2. Trauma



A 28-year-old male undergoes reamed intramedullary nailing for a closed, high-energy midshaft tibia fracture. In the PACU, he develops severe, unrelenting leg pain out of proportion to the injury, exacerbated by passive stretch of the hallux. Intracompartmental pressures confirm compartment syndrome. If a four-compartment fasciotomy is performed via a standard two-incision technique, the lateral incision provides direct access to which compartments?

. Anterior and deep posterior
. Anterior and lateral
. Lateral and superficial posterior
. Superficial posterior and deep posterior
. Anterior and superficial posterior

Correct Answer & Explanation

. Anterior and lateral

Explanation

The standard two-incision technique for lower leg fasciotomy involves an anterolateral incision and a posteromedial incision. The anterolateral incision is placed between the tibial crest and the fibula, providing access to release the anterior and lateral compartments. The posteromedial incision allows for release of the superficial and deep posterior compartments.

Test Yourself

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

On this Page