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2. Trauma MCQs

Practice Set 245 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 4881

Topic: 2. Trauma
A 32-year-old male sustains a Gustilo-Anderson Type IIIB open tibia fracture in the middle third of the diaphysis. Following initial aggressive debridement and external fixation, there remains a 5x5 cm soft tissue defect with exposed tibial cortex devoid of periosteum. Which of the following is the most classic and appropriate soft tissue coverage option for this specific defect?
. Medial gastrocnemius rotational flap
. Reverse sural artery rotational flap
. Free anterolateral thigh (ALT) fasciocutaneous flap
. Soleus rotational flap
. Split-thickness skin grafting directly over the bone

Correct Answer & Explanation

. Soleus rotational flap

Explanation

Local soft tissue coverage for the tibia is classically divided by thirds. Defects in the proximal third are typically covered by a medial or lateral gastrocnemius rotational flap. Defects in the middle third are optimally covered by a soleus rotational flap. Defects in the distal third generally require free tissue transfer (e.g., ALT or latissimus dorsi) or a reverse sural artery flap.

Question 4882

Topic: 2. Trauma
A 7-year-old boy falls on an outstretched hand and presents to the ER. Radiographs demonstrate a fracture of the proximal third of the ulna with an anterior dislocation of the radial head. According to the Bado classification system, what type of Monteggia fracture pattern does this represent?
. Type I
. Type II
. Type III
. Type IV
. Type V

Correct Answer & Explanation

. Type I

Explanation

The Bado classification categorizes Monteggia fractures (proximal ulnar fracture with radial head dislocation) based on the direction of the radial head displacement. Type I involves anterior dislocation of the radial head (with anterior angulation of the ulnar fracture) and is the most common type. Type II is posterior, Type III is lateral, and Type IV involves fractures of both the radius and ulna shafts with anterior radial head dislocation.

Question 4883

Topic: Lower Extremity Trauma

When utilizing a posteromedial approach for the fixation of a Schatzker IV tibial plateau fracture, the main surgical window is established by utilizing the interval between the medial border of the tibia (pes anserinus) anteriorly and which of the following structures posteriorly?

. Lateral head of the gastrocnemius
. Medial head of the gastrocnemius
. Semimembranosus
. Popliteus
. Soleus

Correct Answer & Explanation

. Medial head of the gastrocnemius

Explanation

The standard posteromedial approach to the tibial plateau utilizes the plane between the pes anserinus (anteriorly/medially) and the medial head of the gastrocnemius (posteriorly). Retracting the medial head of the gastrocnemius laterally and posteriorly exposes the posteromedial aspect of the proximal tibia and protects the neurovascular bundle.

Question 4884

Topic: 2. Trauma
A 28-year-old male sustains a vertically oriented (Pauwels Type III) femoral neck fracture. Based on biomechanical studies, which of the following internal fixation constructs provides the greatest stability against the high vertical shear forces inherent to this fracture pattern?
. Three parallel cancellous cannulated screws in an inverted triangle
. Two parallel cancellous cannulated screws
. A fixed-angle sliding hip screw (DHS) with an additional anti-rotation cancellous screw
. A cephalomedullary nail without a derotation screw
. A partially threaded 7.3 mm single lag screw

Correct Answer & Explanation

. A fixed-angle sliding hip screw (DHS) with an additional anti-rotation cancellous screw

Explanation

Pauwels Type III femoral neck fractures have a fracture angle greater than 50 degrees from the horizontal, leading to extremely high vertical shear forces at the fracture site. Biomechanical studies demonstrate that a fixed-angle device, such as a sliding hip screw (DHS), combined with an anti-rotation cancellous screw provides superior resistance to vertical shear compared to multiple parallel cancellous screws alone.

Question 4885

Topic: 2. Trauma

A 35-year-old male sustains a closed, isolated transverse fracture of the middle third of the humeral shaft resulting from a direct blow. On initial examination in the emergency department, he is unable to extend his wrist or digits. The skin is intact and distal pulses are palpable. What is the most appropriate management regarding his radial nerve palsy?

. Immediate operative exploration of the radial nerve with plate osteosynthesis
. Operative exploration if there is no electromyographic (EMG) evidence of recovery at 3 weeks
. Non-operative management with a functional brace and observation of nerve recovery
. Closed reduction and immediate ultrasound-guided perineural corticosteroid injection
. Immediate exploration and nerve grafting

Correct Answer & Explanation

. Non-operative management with a functional brace and observation of nerve recovery

Explanation

A primary radial nerve palsy in the setting of a closed humeral shaft fracture (without vascular compromise) is generally a neuropraxia and has a spontaneous recovery rate of >70-90%. The standard of care is non-operative management with a functional brace and clinical observation. Immediate exploration is reserved for open fractures, associated vascular injuries requiring repair, penetrating trauma, or secondary palsies that develop after closed reduction.

Question 4886

Topic: 2. Trauma

According to the Hertel criteria, which of the following radiographic parameters is the most reliable predictor of subsequent avascular necrosis (AVN) following a proximal humerus fracture?

. Anatomical neck fracture pattern with a metaphyseal head extension (calcar length) of less than 8 mm
. Greater tuberosity displacement of more than 1 cm
. Four-part fracture classification by Neer criteria
. Angulation of the humeral head > 20 degrees
. Medial hinge displacement of less than 2 mm

Correct Answer & Explanation

. Anatomical neck fracture pattern with a metaphyseal head extension (calcar length) of less than 8 mm

Explanation

Hertel et al. identified specific radiographic criteria highly predictive of humeral head ischemia and subsequent AVN. The most significant predictors include an anatomic neck fracture pattern, a short calcar segment (metaphyseal head extension less than 8 mm), and disruption of the medial hinge (> 2 mm displacement). A metaphyseal head extension < 8 mm was shown to have a very high positive predictive value for ischemia.

Question 4887

Topic: 2. Trauma

A 45-year-old male is undergoing open reduction and internal fixation of a severe tibial pilon fracture using an anterolateral approach to the distal tibia. During the superficial surgical dissection, which neural structure is most directly at risk and must be identified and protected?

. Sural nerve
. Saphenous nerve
. Superficial peroneal nerve
. Deep peroneal nerve
. Tibial nerve

Correct Answer & Explanation

. Superficial peroneal nerve

Explanation

The anterolateral approach to the distal tibia/pilon frequently utilizes the interval between the fibula and tibia (between peroneus tertius and extensor digitorum longus). The superficial peroneal nerve pierces the deep fascia in the distal third of the leg and its terminal branches cross directly over the anterolateral surgical field, putting them at significant risk of iatrogenic injury during the superficial dissection.

Question 4888

Topic: 2. Trauma

A 24-year-old male with bilateral femoral shaft fractures develops severe hypoxia, tachycardia, and a non-blanching rash on his axillae and chest 36 hours after injury. According to Gurd's criteria for the diagnosis of Fat Embolism Syndrome, which of the following clinical findings represents one of the 'major' criteria?

. Tachycardia greater than 120 beats per minute
. Petechial rash
. Unexplained fever > 39°C
. Sudden drop in hematocrit
. Retinal microhemorrhages

Correct Answer & Explanation

. Petechial rash

Explanation

Gurd's diagnostic criteria for Fat Embolism Syndrome (FES) include major and minor criteria. The three major criteria are: 1) Respiratory insufficiency (hypoxemia), 2) Cerebral involvement (neurologic dysfunction/confusion), and 3) Petechial rash (typically on the axillae, chest, conjunctiva, or palate). Tachycardia, fever, retinal changes, and drops in hemoglobin/platelets are considered minor criteria.

Question 4889

Topic: 2. Trauma

A 45-year-old male sustains a closed posteromedial tibial plateau fracture after falling from a ladder. Which of the following surgical approaches and patient positionings provides the most optimal access for direct reduction and buttress plating of this specific fracture fragment?

. Supine, anterolateral approach
. Prone, posteromedial approach
. Supine, direct medial approach
. Lateral decubitus, posterolateral approach
. Supine, medial parapatellar approach

Correct Answer & Explanation

. Prone, posteromedial approach

Explanation

Posteromedial tibial plateau fractures exhibit a vertically oriented shear fragment. A prone position with a posteromedial approach allows direct visualization, perpendicular lag screw placement, and optimal anti-glide buttress plating.

Question 4890

Topic: 2. Trauma

A 72-year-old male sustains a Type II odontoid fracture following a ground-level fall. Nonoperative management with a rigid cervical collar is being considered. Which of the following radiographic parameters is the most significant predictor of nonunion for this fracture pattern?

. Initial fracture angulation of 5 degrees
. Anterior displacement of 2 mm
. Presence of a concomitant C1 arch fracture
. Initial fracture displacement greater than 5 mm
. Distance between the fracture gap of 1 mm

Correct Answer & Explanation

. Initial fracture displacement greater than 5 mm

Explanation

Risk factors for nonunion of Type II odontoid fractures include initial displacement greater than 5 mm, angulation greater than 10 degrees, age > 65 years, and delayed treatment. A displacement > 5 mm drastically decreases the likelihood of union with conservative management.

Question 4891

Topic: 2. Trauma

An 80-year-old female falls onto her hip and sustains a severe acetabular fracture. Anteroposterior and Judet oblique pelvic radiographs demonstrate a pathognomonic "spur sign." This radiographic finding definitively indicates which of the following Letournel fracture patterns?

. T-type fracture
. Anterior column posterior hemitransverse fracture
. Both-column fracture
. Transverse with posterior wall fracture
. Isolated posterior column fracture

Correct Answer & Explanation

. Both-column fracture

Explanation

The "spur sign" is seen on the obturator oblique view and is pathognomonic for a both-column acetabular fracture. It represents the uninjured superior portion of the iliac wing, from which the entire articular surface has been disconnected and medially displaced.

Question 4892

Topic: 2. Trauma

A 28-year-old male polytrauma patient arrives with bilateral femur fractures, pulmonary contusions, and a closed head injury. The decision is being made between Early Total Care (ETC) and Damage Control Orthopedics (DCO). Which of the following physiologic parameters is an accepted absolute indication for DCO?

. Serum lactate of 1.8 mmol/L
. Base deficit greater than 8 mEq/L
. Core body temperature of 36.0 degrees Celsius
. Systolic blood pressure of 105 mmHg after initial fluid resuscitation
. Urine output of 1.0 mL/kg/hr

Correct Answer & Explanation

. Base deficit greater than 8 mEq/L

Explanation

Damage Control Orthopedics (DCO) is indicated in the presence of the "lethal triad" or severe physiologic exhaustion. Accepted criteria for DCO include a base deficit > 8 mEq/L, pH < 7.24, core temperature < 35 degrees C, and coagulopathy.

Question 4893

Topic: 2. Trauma

A 22-year-old male sustains a comminuted fracture of the tibial diaphysis. Overnight, he complains of severe pain out of proportion to the injury. The clinical suspicion for acute compartment syndrome is high, and intracompartmental pressures are measured. Which of the following calculations strictly defines the accepted threshold (Delta P) for diagnosing compartment syndrome?

. Mean arterial pressure minus compartment pressure < 30 mmHg
. Diastolic blood pressure minus compartment pressure < 30 mmHg
. Systolic blood pressure minus compartment pressure < 30 mmHg
. Compartment pressure minus central venous pressure > 20 mmHg
. Absolute compartment pressure strictly > 25 mmHg regardless of blood pressure

Correct Answer & Explanation

. Diastolic blood pressure minus compartment pressure < 30 mmHg

Explanation

The Delta P is the most reliable objective measure for diagnosing compartment syndrome. It is calculated as the diastolic blood pressure minus the intracompartmental pressure. A Delta P of less than 30 mmHg is an indication for emergent fasciotomies.

Question 4894

Topic: 2. Trauma
A 38-year-old male sustains a high-energy Pauwels Type III (vertical) femoral neck fracture. A fixed-angle sliding hip screw (SHS) with a derotational screw is chosen over multiple parallel cancellous screws. What is the primary biomechanical rationale for this choice?
. Increased resistance to vertical shear forces
. Decreased incidence of avascular necrosis of the femoral head
. Prevention of varus collapse by preserving the lateral femoral wall
. Superior rotational control of the femoral head
. Elimination of the need for capsulotomy

Correct Answer & Explanation

. Increased resistance to vertical shear forces

Explanation

Pauwels Type III femoral neck fractures have a high vertically oriented fracture line, making them highly subjected to vertical shear forces. A fixed-angle device, such as a sliding hip screw, provides superior biomechanical resistance to vertical shear compared to parallel cancellous screws.

Question 4895

Topic: 2. Trauma

A 65-year-old female sustains a 3-part proximal humerus fracture. The surgeon is evaluating the risk of avascular necrosis (AVN) of the humeral head to decide between ORIF and arthroplasty. According to Hertel's criteria, which of the following findings is the most reliable predictor of humeral head ischemia?

. Metaphyseal head extension less than 8 mm
. Intact medial hinge
. Greater tuberosity displacement of 5 mm
. Valgus impaction of the humeral head
. Head-shaft angle greater than 130 degrees

Correct Answer & Explanation

. Intact medial hinge

Explanation

Hertel's criteria describe predictors of humeral head ischemia in proximal humerus fractures. The most significant predictors include a short metaphyseal head extension (<8 mm), disruption of the medial hinge (>2 mm displacement), and an anatomic neck fracture pattern.

Question 4896

Topic: Pelvic & Acetabular Trauma
Six weeks later the boy remains uncomfortable and continues to use crutches for all ambulation. What do the new radiographs seen in Figures 78a and 78b reveal?
. Osteonecrosis
. Chondrolysis
. Fixation failure at the femoral neck
. Screw cutout of the femoral head

Correct Answer & Explanation

. Fixation failure at the femoral neck

Explanation

Discussion for questions 77 and 78: It has been demonstrated on a cadaver model that screw fixation of moderate and severe slipped capital femoral epiphyses may result in screw impingement upon the acetabulum and labrum. This is likely when the screw head on the anteroposterior view is seen to lie medial to the intertrochanteric line. Femoral artery pseudoaneurysm has been reported when the screws are left long (projecting far from the bone) to ease removal. Chondrolysis is associated with persistent penetration into the hip joint; both screws stop well short of the articular surface. Many in vitro studies of slip models have demonstrated increased strength of construct of two screws compared to one, although the clinical relevance can be questioned. The radiographs show the screw heads firmly in the femoral head, with loss of fixation in the femoral neck. Sanders and associates reported a series of 7 such failures and hypothesized that acute-on-chronic slips may develop osteopenia of the femoral neck. All patients reported continued pain postoperatively rather than the relief typically seen following surgical stabilization of the epiphysis. There is no radiographic evidence of osteonecrosis or chondrolysis.

Question 4897

Topic: 2. Trauma

Patient outcomes can be improved and early post-injury management errors decreased by adhering to the Advanced Trauma Life Support (ATLS) protocol. This protocol includes criteria for inter-hospital transfer when the patient's needs exceed the resources available. Which of the following would it be acceptable to manage without interfacility transfer to a trauma center?

. A 29-year-old man with an open pelvic fracture
. A 42-year-old man with a major extremity crush injury
. A 31-year-old woman with an open forearm fracture
. A 36-year-old man with a spleen laceration after blunt trauma who is clinically stable and whose spleen laceration does not meet criteria for operative management
. An 18-year-old woman with multiple proximal long bone fractures

Correct Answer & Explanation

. A 36-year-old man with a spleen laceration after blunt trauma who is clinically stable and whose spleen laceration does not meet criteria for operative management

Explanation

Patients with severe open fractures should be managed at a trauma center. A patient with an isolated open forearm fracture may not require transfer if her injury is isolated, relatively free of contamination and not otherwise complicated by other factors such as tissue ischemia or tissue loss.While most patients can receive all their definitive care at any hospital to which they present, early recognition of those that require transfer to a trauma center is essential to maximizing outcomes. Inherent in such identification is physician's' assessment of their own and their institutions' abilities and the limits thereof.Van Olden et al. prospectively studied severely injured patients consecutively presenting to two community hospitals in the Netherlands. Comparison was made between patients treated prior to and after introduction of ATLS training to physicians at the studied hospitals. There was no difference in overall mortality between the two groups. however, there was a significant reduction in mortality in the first 60 minutes after admission, from 24.2% pre-ATLS to 0.0% post-ATLS.Ali et al. studied trauma outcomes and mortality in patients presenting to the largest hospital in Trinidad and Tobago for the four years prior to and after introduction of ATLS training for physicians in the emergency department. Trauma mortality decreased to 33.5% from 67.5% after introduction of ATLS. Post-injury functional outcomes were also improved.Illustration A shows the ATLS guidelines for interfacility transfer in table format. Incorrect answers:

Question 4898

Topic: 2. Trauma

A 45-year-old man sustained the injury shown in Figures 18a through 18c. He is neurologically intact. Which of the following is the most appropriate treatment? Review Topic

. A lumbar corset
. A thoracolumbosacral orthosis (TLSO) and immediate mobilization with repeat scans in 6 weeks
. Anterior corpectomy and fusion alone
. Posterior laminectomy without fusion
. Posterior fusion with instrumentation

Correct Answer & Explanation

. Posterior fusion with instrumentation

Explanation

The CT scan reveals a thoracolumbar compression fracture with some height loss and minimal kyphosis. The T2-weighted MRI scan shows discontinuity of the posterior interspinous and supraspinous ligaments and ligamentum flavum. The STIR images demonstrate a discrete region of hyperintensity in the posterior region at the level of the injury. Thoracolumbar fractures with posterior ligamentous injury are potentially unstable. A lumbar corset brace would provide insufficient immobilization of this injury. A laminectomy alone is not indicated and in fact would further destabilize the injury. Whereas an anterior corpectomy could be performed, it should be accompanied by rigid instrumentation. If nonsurgical management with a TLSO and immediate mobilization is elected, serial radiographs should be obtained in the early post-injury period. Posterior fusion with instrumentation allows mobilization without fear of secondary displacement.

Question 4899

Topic: 2. Trauma
A 55-year-old active left-hand-dominant woman sustains a minimally displaced (less than 2 mm displaced) left proximal humerus fracture that involves fractures of the greater tuberosity and surgical neck. Her activities include tennis and golf. What is the best treatment for this patient?
. Nonsurgical treatment
. Percutaneous skeletal fixation
. Open reduction and internal fixation
. Total shoulder arthroplasty

Correct Answer & Explanation

. Nonsurgical treatment

Explanation

Discussion: Literature guiding indications for surgical vs nonsurgical treatment of proximal humerus fractures is not definitive. Many of the recommendations are based on older, nonrandomized series. Newer data suggest that surgical and nonsurgical treatment provide comparable results. Although surgical treatment is preferred for treatment of displaced fractures, fractures with minimal displacement are best managed without surgery.

Question 4900

Topic: 2. Trauma

A 19-year-old collegiate track athlete complains of vague dorsal midfoot pain over the last 3 months. A CT scan confirms an incomplete stress fracture of the dorsal cortex of the tarsal navicular without displacement. What is the recommended initial management?

. Protected weight-bearing in a CAM boot for 4 weeks
. Six weeks of strict non-weight-bearing in a short leg cast
. Percutaneous retrograde screw fixation
. Open reduction and internal fixation with a dorsal plate
. Corticosteroid injection and immediate return to play

Correct Answer & Explanation

. Six weeks of strict non-weight-bearing in a short leg cast

Explanation

Non-displaced or incomplete tarsal navicular stress fractures should be treated with strict non-weight-bearing in a short leg cast for 6 weeks. Weight-bearing modalities have an unacceptably high rate of delayed union or nonunion.

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