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2. Trauma MCQs

Practice Set 499 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 9961

Topic: 2. Trauma

A 35-year-old farm worker sustains an open tibial shaft fracture heavily contaminated with soil. Which of the following antibiotic regimens is most appropriate according to current evidence-based guidelines?

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

Correct Answer & Explanation

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

Explanation

Farm injuries are highly associated with Clostridium species. Current guidelines recommend a first-generation cephalosporin, an aminoglycoside for Gram-negative coverage, and high-dose penicillin for anaerobes.

Question 9962

Topic: 2. Trauma

A 30-year-old man undergoes intramedullary nailing of a closed tibial shaft fracture. Postoperatively, he develops severe pain out of proportion, not relieved by opioids. Passive stretch of the toes exacerbates the pain. Compartment pressure is 35 mmHg and diastolic blood pressure is 60 mmHg. What is the delta pressure, and what is the indicated management?

. 25 mmHg; immediate fasciotomy
. 25 mmHg; elevate the leg and observe
. 35 mmHg; immediate fasciotomy
. 35 mmHg; elevate the leg and observe
. 95 mmHg; immediate fasciotomy

Correct Answer & Explanation

. 35 mmHg; immediate fasciotomy

Explanation

The delta pressure (diastolic BP minus compartment pressure) is 60 - 35 = 25 mmHg. A delta pressure of < 30 mmHg is highly indicative of acute compartment syndrome, and emergent four-compartment fasciotomy is indicated.

Question 9963

Topic: 2. Trauma
A 65-year-old female sustains a vertically oriented (Pauwels type III) femoral neck fracture. To maximize biomechanical stability and preserve the primary vascular supply to the femoral head, which structure must be protected and what is its anatomic course?
. Lateral circumflex femoral artery, passing anterior to the intertrochanteric line
. Medial circumflex femoral artery, with its deep branch passing posterior to the obturator externus
. Artery of the ligamentum teres, arising directly from the internal iliac artery
. Inferior gluteal artery, passing superior to the piriformis
. First perforating branch of the profunda femoris, piercing the adductor magnus

Correct Answer & Explanation

. Medial circumflex femoral artery, with its deep branch passing posterior to the obturator externus

Explanation

The deep branch of the medial circumflex femoral artery provides the predominant blood supply to the adult femoral head. It courses posterior to the obturator externus and anterior to the short external rotators before entering the capsule.

Question 9964

Topic: 2. Trauma

A 28-year-old male sustains a spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture) and presents with a newly identified wrist drop. The injured nerve travels through the spiral groove in direct company with which vascular structure?

. Brachial artery
. Anterior circumflex humeral artery
. Superior ulnar collateral artery
. Profunda brachii artery
. Radial recurrent artery

Correct Answer & Explanation

. Profunda brachii artery

Explanation

The radial nerve courses through the spiral groove of the humerus accompanied by the profunda brachii artery. Injury here typically results in a radial nerve palsy, characteristic of Holstein-Lewis fractures.

Question 9965

Topic: 2. Trauma

An 80-year-old female sustains a reverse obliquity intertrochanteric proximal femur fracture (AO/OTA 31-A3). Why is a cephalomedullary nail biomechanically superior to a sliding hip screw for this specific fracture pattern?

. Sliding hip screws result in excessive medialization of the distal fragment due to loss of lateral wall buttress
. Intramedullary nails provide a dynamic compression effect directly across the subtrochanteric region
. Sliding hip screws completely disrupt the medial circumflex femoral artery during plate application
. Intramedullary nails allow immediate full weight-bearing irrespective of bone quality
. Reverse obliquity fractures heal primarily through enchondral ossification which plates inhibit

Correct Answer & Explanation

. Sliding hip screws result in excessive medialization of the distal fragment due to loss of lateral wall buttress

Explanation

In reverse obliquity fractures, the intact medial cortex combined with a compromised lateral wall means a sliding hip screw will allow the femoral shaft to medialize excessively. An intramedullary nail acts as an internal lateral buttress, preventing this displacement.

Question 9966

Topic: 2. Trauma

In the treatment of a 12-year-old's femoral shaft fracture, utilization of a piriformis fossa entry portal for rigid intramedullary nailing is contraindicated. Which specific vascular structure is jeopardized by this starting point?

. Ascending branch of the lateral circumflex femoral artery
. Deep branch of the medial circumflex femoral artery
. Artery of the ligamentum teres
. Inferior gluteal artery
. First perforating branch of the profunda femoris

Correct Answer & Explanation

. Deep branch of the medial circumflex femoral artery

Explanation

A piriformis fossa entry point in skeletally immature patients carries a high risk of iatrogenic avascular necrosis. It directly threatens the deep branch of the medial circumflex femoral artery at the posterosuperior femoral neck.

Question 9967

Topic: 2. Trauma

A 35-year-old male sustains a posterior hip dislocation with an associated femoral head fracture occurring inferior to the fovea capitis, alongside a posterior wall acetabular fracture (Pipkin IV). What is the primary anatomical explanation for the high rate of avascular necrosis in this injury?

. Direct crush injury to the artery of the ligamentum teres
. Disruption of the retinacular vessels arising from the medial circumflex femoral artery
. Laceration of the lateral circumflex femoral artery by the posterior wall fragment
. Avulsion of the inferior gluteal artery at the greater sciatic notch
. Thrombosis of the external iliac artery due to severe hip hyperflexion

Correct Answer & Explanation

. Disruption of the retinacular vessels arising from the medial circumflex femoral artery

Explanation

Posterior hip dislocations, particularly those associated with severe trauma like Pipkin IV fractures, stretch and tear the posterior capsule and the ascending retinacular branches of the medial circumflex femoral artery, leading to AVN.

Question 9968

Topic: 2. Trauma

A 28-year-old male arrives in the trauma bay with his right lower extremity fixed in extension, external rotation, and abduction. A superior (pubic) anterior hip dislocation is confirmed. What is the most critical immediate local vascular risk to evaluate?

. Laceration of the deep branch of the medial circumflex femoral artery
. Avulsion of the internal iliac artery
. Occlusion or compression of the common femoral artery
. Rupture of the superior gluteal artery
. Thrombosis of the popliteal artery

Correct Answer & Explanation

. Occlusion or compression of the common femoral artery

Explanation

Superior (pubic) anterior hip dislocations force the femoral head anteriorly and superiorly, placing it in direct proximity to the femoral neurovascular bundle, creating a high risk for common femoral artery and vein compression or laceration.

Question 9969

Topic: 2. Trauma

During a Kocher-Langenbeck approach for a posterior wall acetabular fracture, the gluteus maximus is split bluntly in line with its fibers. To preserve the primary vascular supply to the superior portion of the gluteus maximus, which vessel must be protected from over-retraction?

. Inferior gluteal artery
. Superior gluteal artery
. Internal pudendal artery
. First perforating branch of the profunda femoris
. Medial circumflex femoral artery

Correct Answer & Explanation

. Superior gluteal artery

Explanation

The superior gluteal artery exits the greater sciatic foramen superior to the piriformis and supplies the proximal/superior half of the gluteus maximus. Excessive medial retraction or proximal splitting risks tearing this friable vessel.

Question 9970

Topic: Upper Extremity Trauma

Recent anatomical studies regarding the vascular supply of the proximal humerus demonstrate that the predominant blood supply to the humeral head is provided by which of the following vessels?

. Anterior humeral circumflex artery
. Posterior humeral circumflex artery
. Arcuate artery
. Thoracoacromial artery
. Subscapular artery

Correct Answer & Explanation

. Posterior humeral circumflex artery

Explanation

Classic teaching highlighted the anterior humeral circumflex artery as the primary supply via its arcuate branch. However, recent quantitative studies prove the posterior humeral circumflex artery provides approximately 64% of the blood supply to the humeral head.

Question 9971

Topic: 2. Trauma

A 35-year-old male presents with a closed distal-third spiral fracture of the humeral shaft. Following closed reduction and splinting in the emergency department, he develops a new-onset complete wrist drop and inability to extend his metacarpophalangeal joints. What is the most appropriate next step in management?

. Immediate surgical exploration of the radial nerve and fracture fixation
. Electromyography (EMG) at 3 weeks
. Observation and continuation of non-operative management
. Ultrasound-guided nerve block
. Corticosteroid injection into the fracture site

Correct Answer & Explanation

. Immediate surgical exploration of the radial nerve and fracture fixation

Explanation

A secondary radial nerve palsy that develops after a closed reduction of a distal-third spiral humeral shaft fracture (Holstein-Lewis) strongly suggests iatrogenic nerve entrapment. This is an absolute indication for immediate surgical exploration and internal fixation.

Question 9972

Topic: 2. Trauma

In the treatment of an intertrochanteric femoral fracture, preoperative templating demonstrates a lateral wall thickness of 18 mm. Which of the following is the most appropriate fixation construct to minimize the risk of mechanical failure?

. Sliding hip screw with a 2-hole side plate
. Sliding hip screw with a 4-hole side plate
. Short cephalomedullary nail
. Multiple cancellous screws
. Dynamic condylar screw

Correct Answer & Explanation

. Short cephalomedullary nail

Explanation

A lateral wall thickness of less than 20.5 mm in an intertrochanteric fracture defines an incompetent lateral wall. Using a sliding hip screw in this setting carries a high rate of lateral wall blowout, making a cephalomedullary nail the treatment of choice.

Question 9973

Topic: 2. Trauma

A 28-year-old polytrauma patient sustains a floating elbow injury with an associated brachial artery transection resulting in an ischemic, pulseless hand. What is the correct sequence of surgical management?

. Arterial repair, followed by skeletal fixation, followed by fasciotomies
. Skeletal fixation, followed by arterial repair, followed by fasciotomies
. Temporary vascular shunt, followed by skeletal fixation, followed by definitive arterial repair and fasciotomies
. Fasciotomies, followed by arterial repair, followed by skeletal fixation
. Immediate amputation due to prolonged ischemia

Correct Answer & Explanation

. Temporary vascular shunt, followed by skeletal fixation, followed by definitive arterial repair and fasciotomies

Explanation

In an ischemic limb with highly unstable fractures, a temporary intravascular shunt must be placed first to quickly restore perfusion. This is followed by stable skeletal fixation, definitive arterial repair, and prophylactic fasciotomies.

Question 9974

Topic: 2. Trauma

A 40-year-old male sustains a posterior hip dislocation with an associated femoral head fracture (Pipkin IV). A surgical dislocation of the hip (Ganz approach) is planned. To preserve the MFCA blood supply to the femoral head, the trochanteric flip osteotomy must keep which muscle attachments intact on the greater trochanter?

. Gluteus medius and piriformis
. Gluteus minimus and short external rotators
. Gluteus medius, gluteus minimus, and vastus lateralis
. Obturator externus and quadratus femoris
. Iliopsoas and pectineus

Correct Answer & Explanation

. Gluteus medius, gluteus minimus, and vastus lateralis

Explanation

The Ganz trochanteric flip osteotomy meticulously preserves the insertions of the gluteus medius, gluteus minimus, and vastus lateralis on the trochanteric fragment. The external rotators remain intact on the femur, thereby protecting the deep branch of the MFCA.

Question 9975

Topic: 2. Trauma
A 25-year-old male sustains a high-energy Pauwels type III femoral neck fracture. Which of the following internal fixation constructs provides the highest biomechanical stability against vertical shear forces?
. Three parallel cancellous screws in an inverted triangle
. Three parallel cancellous screws in a standard triangle
. A sliding hip screw with a derotation cancellous screw
. Fully threaded cortical screws alone
. Non-operative management with skeletal traction

Correct Answer & Explanation

. A sliding hip screw with a derotation cancellous screw

Explanation

Pauwels type III fractures are highly unstable vertically due to their steep shear angle. Biomechanical studies consistently show that a fixed-angle construct, such as a sliding hip screw with an anti-rotation screw, provides superior stability against vertical shear compared to cancellous screws alone.

Question 9976

Topic: 2. Trauma

A 35-year-old male sustains a Holstein-Lewis fracture of the humerus. Which nerve is most classically at risk for neuropraxia or entrapment in this specific injury pattern?

. Axillary nerve
. Ulnar nerve
. Median nerve
. Radial nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Radial nerve

Explanation

A Holstein-Lewis fracture is a spiral fracture of the distal third of the humeral shaft. It is classically associated with radial nerve injury as the nerve passes through the lateral intermuscular septum and can become entrapped by the fracture fragments.

Question 9977

Topic: 2. Trauma

In the Pipkin classification of femoral head fractures associated with posterior hip dislocations, which description accurately defines a Type II fracture?

. Femoral head fracture strictly below the fovea capitis
. Femoral head fracture extending above the fovea capitis
. Femoral head fracture associated with a femoral neck fracture
. Femoral head fracture associated with an acetabular fracture
. Isolated chondral avulsion of the ligamentum teres

Correct Answer & Explanation

. Femoral head fracture extending above the fovea capitis

Explanation

A Pipkin Type II fracture involves a posterior hip dislocation with a femoral head fracture that extends cephalad to the fovea capitis. Because it involves the major weight-bearing dome, it often requires operative fixation to restore joint congruity.

Question 9978

Topic: 2. Trauma

Which of the following clinical scenarios represents an absolute indication for immediate operative fixation of a humeral shaft fracture?

. An oblique midshaft fracture with 15 degrees of varus angulation
. A complete radial nerve palsy present prior to closed reduction
. An open humeral shaft fracture
. A transverse fracture with 2 cm of shortening
. A segmental humerus fracture in a polytrauma patient with no head injury

Correct Answer & Explanation

. An open humeral shaft fracture

Explanation

Open humeral shaft fractures represent an absolute indication for surgical management to allow for thorough debridement, irrigation, and stable fixation. Primary radial nerve palsy before reduction is generally observed, as the majority of cases are neuropraxias that spontaneously recover.

Question 9979

Topic: 2. Trauma

According to the Neer classification for proximal humerus fractures, what criteria must be met for a fracture segment to be considered a separate, "displaced" part?

. >1 cm of separation or >45 degrees of angulation
. >5 mm of separation or >20 degrees of angulation
. >2 cm of separation or >30 degrees of angulation
. >1 cm of separation or >30 degrees of angulation
. >5 mm of separation or >45 degrees of angulation

Correct Answer & Explanation

. >1 cm of separation or >45 degrees of angulation

Explanation

The Neer classification defines a "part" as displaced if there is greater than 1 cm of separation or greater than 45 degrees of angulation between the fracture fragments relative to their normal anatomical position.

Question 9980

Topic: 2. Trauma

When evaluating an intertrochanteric hip fracture, which anatomical feature is the most critical determinant of fracture stability following internal fixation?

. The integrity of the greater trochanter
. The extent of comminution in the anterior femoral neck
. The integrity of the posteromedial cortex (calcar)
. The vertical distance between the fracture line and the piriformis fossa
. The angle of the neck-shaft alignment prior to injury

Correct Answer & Explanation

. The integrity of the posteromedial cortex (calcar)

Explanation

The integrity of the posteromedial cortex, often referred to as the calcar, is the most critical determinant of stability in intertrochanteric fractures. It functions as a primary buttress against compressive forces, and its loss leads to varus collapse and implant failure.

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