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2. Trauma MCQs

Practice Set 250 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 4981

Topic: Upper Extremity Trauma

During surgical reconstruction of a severe acromioclavicular (AC) joint separation, precise knowledge of the coracoclavicular (CC) ligament insertions is required. Which of the following best describes the normal anatomic footprint of the CC ligaments on the clavicle?

. The conoid ligament inserts on the anterolateral clavicle, approximately 2.5 cm from the distal end.
. The trapezoid ligament inserts on the posteromedial clavicle, approximately 4.5 cm from the distal end.
. The conoid ligament inserts on the posteromedial aspect of the distal clavicle, approximately 4.5 cm from the AC joint.
. The trapezoid ligament inserts on the posteromedial aspect of the distal clavicle, approximately 3.0 cm from the AC joint.
. Both ligaments blend together and insert at the exact same footprint on the inferior clavicle, 1.0 cm from the AC joint.

Correct Answer & Explanation

. The conoid ligament inserts on the posteromedial aspect of the distal clavicle, approximately 4.5 cm from the AC joint.

Explanation

The coracoclavicular (CC) ligaments consist of the conoid and trapezoid. The conoid is medial and posterior, inserting approximately 4.5 cm from the distal end of the clavicle. The trapezoid is lateral and anterior, inserting approximately 3.0 cm from the distal clavicle. Mnemonic: 'Conoid is Cone-shaped, medial, and posterior.' Accurate tunnel placement requires knowing these distances.

Question 4982

Topic: Pelvic & Acetabular Trauma
A 40-year-old male is brought into the trauma bay with an APC-III (anteroposterior compression) pelvic ring injury and severe hemodynamic instability. A non-invasive pelvic binder is applied to reduce pelvic volume. To achieve maximal reduction of the symphyseal diastasis and control hemorrhage, over which anatomic landmark should the binder be centered?
. The iliac crests
. The anterior superior iliac spines (ASIS)
. The greater trochanters
. The level of the umbilicus
. The mid-thighs

Correct Answer & Explanation

. The greater trochanters

Explanation

Pelvic binders are a critical first step in managing hemodynamically unstable pelvic ring injuries, particularly open book (APC) patterns. To correctly apply vector force that effectively closes the pelvic ring and reduces the symphyseal diastasis, the binder must be centered directly over the greater trochanters. Placement too high (e.g., over the iliac crests or ASIS) is a common error and is ineffective at reducing pelvic volume.

Question 4983

Topic: 2. Trauma

The Tillaux-Chaput fracture is an important component of complex ankle fractures. It represents an avulsion fracture caused by tension from the anterior inferior tibiofibular ligament (AITFL). From which specific bony structure does this fragment avulse?

. The anteromedial distal fibula
. The anterolateral distal tibia
. The posterolateral distal tibia
. The posteromedial distal fibula
. The medial malleolus

Correct Answer & Explanation

. The anterolateral distal tibia

Explanation

The anterior inferior tibiofibular ligament (AITFL) connects the anterolateral distal tibia to the anteromedial distal fibula. An avulsion fracture of its tibial attachment is the Tillaux-Chaput fragment (anterolateral distal tibia). An avulsion of its fibular attachment is the Wagstaffe-Le Fort fragment. The posterior inferior tibiofibular ligament (PITFL) avulses the posterolateral tibia, known as the Volkmann fragment.

Question 4984

Topic: 2. Trauma
A 40-year-old male sustains an isolated, closed transverse fracture of the femoral shaft in a motor vehicle accident. Reamed intramedullary nailing is planned. What is the primary physiological and clinical benefit of reaming the medullary canal prior to nail insertion compared to an unreamed technique?
. Decreased risk of fat embolism syndrome
. Preservation of the endosteal blood supply
. Shorter total operative time
. Higher rates of fracture union
. Elimination of the need for distal interlocking screws

Correct Answer & Explanation

. Higher rates of fracture union

Explanation

Multiple large randomized trials and meta-analyses have shown that reamed intramedullary nailing of closed femoral shaft fractures yields significantly higher union rates and lower rates of hardware failure compared to unreamed nailing. Reaming allows for a larger, stiffer nail and generates autologous bone graft at the fracture site, outweighing the transient destruction of the endosteal blood supply.

Question 4985

Topic: 2. Trauma

In bridge plating of a highly comminuted distal femur fracture using a lateral locked plate, the surgeon must balance construct stiffness to promote secondary bone healing. Which of the following mechanical choices most significantly decreases construct stiffness to allow the micro-motion necessary for robust callus formation?

. Using stainless steel instead of titanium plates
. Decreasing the plate working length by placing screws as close to the fracture as possible
. Increasing the plate working length by omitting screws immediately adjacent to the fracture gap
. Using unicortical screws in the diaphysis only
. Filling every available screw hole in the plate

Correct Answer & Explanation

. Increasing the plate working length by omitting screws immediately adjacent to the fracture gap

Explanation

In bridge plating, the 'working length' is the distance between the two closest screws on either side of the fracture. Increasing the working length (by leaving holes empty near the fracture) decreases the stiffness of the construct, allowing for interfragmentary strain and micro-motion. This micro-motion is essential for secondary bone healing via callus formation. Constructs that are too stiff (short working length, filling every hole) suppress callus and contribute to nonunion.

Question 4986

Topic: 2. Trauma

A 25-year-old male sustains a closed comminuted tibial shaft fracture. Two hours post-injury, he complains of severe pain out of proportion to the injury. Which of the following hemodynamic measurements provides the most reliable indication for performing a four-compartment fasciotomy?

. Absolute compartment pressure > 20 mmHg
. Absolute compartment pressure > 30 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 less than 30 mmHg is an absolute indication for fasciotomy. Absolute pressure thresholds (e.g., 30 mmHg) can lead to overtreatment in hypotensive patients and undertreatment in hypertensive patients.

Question 4987

Topic: 2. Trauma
A 35-year-old male sustains a vertically oriented femoral neck fracture (Pauwels Type III) after falling from a roof. To minimize the risk of varus collapse and nonunion, which internal fixation construct provides the most biomechanically superior stability against shear forces?
. Three parallel cancellous screws placed in an inverted triangle
. A sliding hip screw (SHS) with an anti-rotation screw
. A standard trochanteric entry cephalomedullary nail
. Two divergent cannulated screws
. A fully threaded single lag screw

Correct Answer & Explanation

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

Explanation

Pauwels Type III fractures are vertically oriented (>50 degrees) and experience high shear forces, leading to a high risk of varus collapse. Biomechanical studies have shown that a fixed-angle device, such as a sliding hip screw (often combined with a derotational screw), provides superior stability against vertical shear forces compared to multiple cancellous screws.

Question 4988

Topic: 2. Trauma

A 21-year-old track athlete presents with insidious onset of vague dorsal midfoot pain. A CT scan reveals a nondisplaced, incomplete stress fracture in the central third of the navicular. What is the most appropriate initial management?

. Open reduction internal fixation with a compression screw
. Closed reduction and percutaneous pinning
. Strict non-weight-bearing in a short leg cast for 6-8 weeks
. Weight-bearing as tolerated in a controlled ankle motion (CAM) boot for 4 weeks
. Extracorporeal shock wave therapy and return to play in 2 weeks

Correct Answer & Explanation

. Strict non-weight-bearing in a short leg cast for 6-8 weeks

Explanation

Navicular stress fractures typically occur in the central third, which is a relative watershed area for blood supply. For nondisplaced and incomplete fractures, the gold standard initial treatment is strict non-weight-bearing in a short leg cast for 6 to 8 weeks to allow for healing and minimize the risk of nonunion.

Question 4989

Topic: 2. Trauma
A 40-year-old farmer sustains a Gustilo-Anderson Type IIIB open tibia fracture heavily contaminated with soil and manure. Based on current guidelines, which of the following prophylactic antibiotic regimens is most appropriate?
. First-generation cephalosporin alone
. First-generation cephalosporin and an aminoglycoside
. First-generation cephalosporin, an aminoglycoside, and high-dose penicillin
. Third-generation cephalosporin alone
. Fluoroquinolone and clindamycin

Correct Answer & Explanation

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

Explanation

For a heavily contaminated farm injury (Type III open fracture), the standard antibiotic prophylaxis includes a first-generation cephalosporin (for Gram-positive coverage), an aminoglycoside (for Gram-negative coverage), and the addition of high-dose penicillin to specifically cover anaerobic organisms, most notably Clostridium species.

Question 4990

Topic: 2. Trauma

The Sanders classification is widely used to categorize intra-articular calcaneus fractures based on coronal CT images. This classification relies specifically on the number and location of fracture lines through which articular facet?

. Anterior facet
. Middle facet
. Posterior facet
. Cuboid articular surface
. Talar dome

Correct Answer & Explanation

. Posterior facet

Explanation

The Sanders classification evaluates intra-articular calcaneal fractures by assessing the number and location of primary fracture lines through the posterior facet of the calcaneus on the widest semicoronal CT image. The posterior facet is the largest and most critical weight-bearing surface of the subtalar joint.

Question 4991

Topic: Upper Extremity Trauma
A 22-year-old male falls directly onto his shoulder tip. Radiographs demonstrate 100% superior displacement of the clavicle relative to the acromion. Based on the Rockwood classification for acromioclavicular (AC) joint injuries, a Type III separation involves complete rupture of which ligaments?
. Acromioclavicular ligaments only
. Coracoclavicular ligaments only
. Both the acromioclavicular and coracoclavicular ligaments
. Acromioclavicular, coracoclavicular, and coracoacromial ligaments
. Coracoacromial and coracoclavicular ligaments

Correct Answer & Explanation

. Both the acromioclavicular and coracoclavicular ligaments

Explanation

In the Rockwood classification: Type I is an AC ligament sprain; Type II is an AC ligament tear with a CC ligament sprain; Type III is a complete rupture of both the AC ligaments and the CC ligaments (conoid and trapezoid), resulting in superior displacement of the clavicle between 25% and 100%.

Question 4992

Topic: 2. Trauma

A 45-year-old driver sustains a posterior wall acetabular fracture in a head-on collision. Which of the following findings is an absolute indication for operative fixation of the posterior wall?

. Fracture involving 10% of the posterior wall
. A completely non-displaced fracture on CT
. An incarcerated intra-articular bone fragment
. An associated, non-displaced anterior column fracture
. A 1 mm articular step-off seen on CT

Correct Answer & Explanation

. An incarcerated intra-articular bone fragment

Explanation

Absolute indications for open reduction and internal fixation of a posterior wall acetabular fracture include hip joint instability (often seen when >20-40% of the wall is involved), the presence of an incarcerated intra-articular osteochondral fragment, and progressive sciatic nerve deficit following a closed reduction.

Question 4993

Topic: 2. Trauma

The FRAX (Fracture Risk Assessment Tool) algorithm is used to calculate the 10-year probability of a major osteoporotic fracture. Which of the following is NOT included as a discrete risk factor variable in the FRAX tool?

. Rheumatoid arthritis
. Current smoking
. History of falls
. Glucocorticoid use
. Parental history of hip fracture

Correct Answer & Explanation

. History of falls

Explanation

Despite a history of falls being one of the most significant clinical predictors of future fracture risk, it is notably absent from the FRAX algorithm. FRAX variables include age, sex, weight, height, prior fracture, parental hip fracture, current smoking, glucocorticoid use, rheumatoid arthritis, secondary osteoporosis, and excessive alcohol intake.

Question 4994

Topic: 2. Trauma
What is the optimal timing for the first dose of zoledronic acid following surgical fixation of an osteoporotic hip fracture to maximize the reduction in mortality and subsequent fracture risk?
. Within 24 hours postoperatively
. 2 to 6 weeks postoperatively
. 3 months postoperatively
. 6 months postoperatively
. 1 year postoperatively

Correct Answer & Explanation

. 2 to 6 weeks postoperatively

Explanation

The HORIZON Recurrent Fracture Trial demonstrated that administering zoledronic acid between 2 and 6 weeks postoperatively resulted in significant reductions in new clinical fractures and mortality. Administration within the first 2 weeks was less effective and did not show the same mortality benefit, likely due to interference with the early acute-phase reaction or early fracture healing physiology.

Question 4995

Topic: 2. Trauma

The Fracture Risk Assessment Tool (FRAX) is widely used to calculate the 10-year probability of a major osteoporotic fracture and a hip fracture. Which of the following clinical variables is NOT included in the FRAX calculation model?

. Current tobacco smoking
. A parental history of a fractured hip
. A history of falls in the past 12 months
. Rheumatoid arthritis
. Current or past use of oral glucocorticoids for > 3 months

Correct Answer & Explanation

. A history of falls in the past 12 months

Explanation

The FRAX tool calculates a 10-year fracture risk based on clinical risk factors and femoral neck BMD. The specific clinical risk factors included are: Age, Sex, Weight, Height, Prior fracture, Parental history of hip fracture, Current smoking, Glucocorticoid use, Rheumatoid arthritis, Secondary osteoporosis, and Alcohol intake (>3 units/day). History of falls, despite being a major independent risk factor for fractures, is notably NOT included in the FRAX algorithm.

Question 4996

Topic: 2. Trauma

An 82-year-old female presents with a periprosthetic femur fracture around a cemented polished taper-slip stem placed 15 years ago. Radiographs reveal a fracture extending just distal to the tip of the stem. The stem is frankly loose. Furthermore, there is severe proximal bone loss with marked cortical thinning, rendering the proximal femur mechanically nonsupportive. According to the Vancouver classification, what is the standard recommended surgical management?

. Open reduction and internal fixation with a lateral locking plate and cerclage cables
. Revision to a standard length uncemented fully porous-coated stem
. Revision to a long cemented stem with impaction bone grafting
. Revision to a modular fluted tapered uncemented diaphyseal-engaging stem or proximal femoral replacement
. Retention of the loose stem and stabilization with a retrograde intramedullary nail

Correct Answer & Explanation

. Revision to a modular fluted tapered uncemented diaphyseal-engaging stem or proximal femoral replacement

Explanation

This is a Vancouver B3 fracture, defined by a fracture around or just below the stem, a loose stem, and poor proximal bone stock. Because the proximal bone cannot provide adequate initial fixation or support, the surgical solution must bypass this area. Standard of care relies on obtaining stable diaphyseal fixation using a distally fixing modular fluted tapered stem, or in cases of extreme comminution and elderly/low-demand patients, utilizing a proximal femoral replacement (megaprosthesis) to allow immediate weight-bearing.

Question 4997

Topic: 2. Trauma
The Fracture Risk Assessment Tool (FRAX) is utilized to estimate the 10-year probability of a major osteoporotic fracture and a hip fracture. Which of the following clinical variables is NOT explicitly included as a risk factor input in the calculation of the FRAX score?
. Diagnosis of Rheumatoid arthritis
. Current smoking status
. Diagnosis of Type 2 Diabetes Mellitus
. History of a prior fragility fracture
. Current or past use of systemic glucocorticoids

Correct Answer & Explanation

. Diagnosis of Type 2 Diabetes Mellitus

Explanation

The FRAX tool includes inputs for age, sex, weight, height, prior fracture, parental history of hip fracture, current smoking, glucocorticoid use, rheumatoid arthritis, secondary osteoporosis, alcohol intake (≥3 units/day), and femoral neck BMD. Although Type 2 Diabetes Mellitus is recognized as a significant risk factor for poor bone quality and fractures, it is not explicitly included as a discrete variable in the standard FRAX calculation, which can sometimes lead to underestimating fracture risk in diabetic patients.

Question 4998

Topic: 2. Trauma

A 78-year-old female sustains a distal femur fracture 5 years after a primary total knee arthroplasty. Radiographs show a displaced, comminuted metaphyseal fracture, but the femoral component remains well-fixed. According to the Rorabeck classification, what is the best surgical treatment?

. Conservative management in a hinged knee brace
. Open reduction and internal fixation with a lateral locking plate
. Revision total knee arthroplasty with a distal femoral replacement
. Removal of hardware and application of a circular external fixator
. Knee arthrodesis with an intramedullary nail

Correct Answer & Explanation

. Open reduction and internal fixation with a lateral locking plate

Explanation

A displaced periprosthetic distal femur fracture with a well-fixed femoral component is classified as Rorabeck Type II. The standard of care is open reduction and internal fixation, typically utilizing a lateral locking plate.

Question 4999

Topic: 2. Trauma

A 32-year-old male is involved in a motorcycle collision and sustains a coronal plane fracture of the lateral femoral condyle (Hoffa fracture). Which of the following describes the optimal lag screw trajectory for maximum biomechanical stability?

. Anterior-to-posterior (AP) directed lag screws
. Posterior-to-anterior (PA) directed lag screws
. Medial-to-lateral directed lag screws
. Inferior-to-superior directed lag screws
. Distal-to-proximal directed lag screws

Correct Answer & Explanation

. Posterior-to-anterior (PA) directed lag screws

Explanation

Hoffa fractures are coronal plane fractures of the femoral condyle (most commonly lateral). Biomechanical studies have shown that posterior-to-anterior (PA) directed lag screws provide superior biomechanical stability compared to AP screws, although AP screws are frequently used clinically due to the ease of an anterior surgical approach.

Question 5000

Topic: 2. Trauma

A 45-year-old male sustains a high-energy medial tibial plateau fracture with widening and depression (Schatzker IV). Preoperative CT scan reveals a significant posteromedial shear fragment. Which surgical approach is most critical for adequate buttress plating of this specific fragment?

. Anterolateral approach
. Direct anterior approach
. Posteromedial approach
. Posterolateral approach
. Medial parapatellar approach

Correct Answer & Explanation

. Posteromedial approach

Explanation

Schatzker IV fractures frequently involve a posteromedial fragment that represents a major destabilizing injury. This fragment requires anti-glide or buttress plating from its posterior aspect to prevent displacement. The posteromedial approach allows direct visualization and orthogonal plating of this fragment.

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