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2. Trauma MCQs

Practice Set 318 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 6341

Topic: 2. Trauma

Which of the following inflammatory markers is considered the most reliable early predictor for the development of acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome (MODS) in a polytrauma patient, guiding the decision between early total care and damage control orthopedics?

. Interleukin-1 (IL-1)
. Interleukin-6 (IL-6)
. Tumor necrosis factor-alpha (TNF-alpha)
. C-reactive protein (CRP)
. Erythrocyte sedimentation rate (ESR)

Correct Answer & Explanation

. Interleukin-6 (IL-6)

Explanation

Interleukin-6 (IL-6) is a pro-inflammatory cytokine that has been shown to be the best early marker for the magnitude of the systemic inflammatory response following major trauma. Peak IL-6 levels correlate closely with the extent of tissue injury, the systemic inflammatory response syndrome (SIRS), and the subsequent development of ARDS, MODS, and mortality. While IL-1 and TNF-alpha are also part of the inflammatory cascade, they have shorter half-lives and are more difficult to measure consistently. CRP and ESR are non-specific and peak much later.

Question 6342

Topic: 2. Trauma

A 32-year-old man sustains a subtrochanteric femur fracture. During attempts at closed reduction, the proximal fracture fragment is noted to be severely flexed, abducted, and externally rotated. The abduction deformity of the proximal fragment is primarily caused by the pull of which of the following muscles?

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

Correct Answer & Explanation

. Iliopsoas

Explanation

In a subtrochanteric femur fracture, the proximal fragment is subjected to distinct deforming forces from the muscles attaching to the proximal femur. The iliopsoas (attaching to the lesser trochanter) pulls the fragment into flexion. The short external rotators pull it into external rotation. The gluteus medius and minimus (attaching to the greater trochanter) pull the fragment into abduction. The distal fragment is typically shortened and adducted by the pull of the adductor musculature.

Question 6343

Topic: 2. Trauma
A 45-year-old farmer is brought to the emergency department after his leg was caught in a tractor mechanism. He has sustained a Gustilo-Anderson Type III open tibia fracture that is heavily contaminated with soil and organic material. In addition to prompt surgical debridement, what is the most appropriate initial intravenous antibiotic regimen according to classic trauma guidelines?
. First-generation cephalosporin alone
. First-generation cephalosporin and an aminoglycoside
. First-generation cephalosporin, an aminoglycoside, and high-dose penicillin
. Third-generation cephalosporin and vancomycin
. Fluoroquinolone and clindamycin

Correct Answer & Explanation

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

Explanation

For Gustilo-Anderson Type III open fractures, standard prophylaxis includes a first-generation cephalosporin (e.g., cefazolin) for Gram-positive coverage and an aminoglycoside (e.g., gentamicin) for expanded Gram-negative coverage. When the injury involves a farm environment, gross soil contamination, or standing water, there is a significantly increased risk of Clostridium infection (gas gangrene). In such high-risk scenarios, high-dose penicillin must be added to the regimen to provide coverage against anaerobic organisms, specifically Clostridium species.

Question 6344

Topic: Pelvic & Acetabular Trauma
A 40-year-old man sustains an anteroposterior compression type III (APC III) pelvic ring injury in a high-speed motorcycle collision. In the trauma bay, a pelvic binder is applied, and he receives massive transfusion protocol. His systolic blood pressure remains 70 mm Hg. The Focused Assessment with Sonography for Trauma (FAST) examination is negative, and a chest radiograph shows no abnormalities. What is the most appropriate next step in the management of this patient?
. Computed tomography (CT) scan of the abdomen and pelvis
. Retrograde urethrogram
. Pelvic angiography with potential embolization
. Exploratory laparotomy
. Application of an external fixator

Correct Answer & Explanation

. Pelvic angiography with potential embolization

Explanation

The patient remains hemodynamically unstable despite a pelvic binder and fluid resuscitation, with a negative FAST exam indicating the absence of massive intra-abdominal hemorrhage. The bleeding is most likely retroperitoneal from the highly unstable APC III pelvic injury. Pelvic angiography is the most appropriate next step to identify and embolize actively bleeding arterial vessels (most commonly branches of the internal iliac artery, such as the superior gluteal or pudendal arteries). CT scanning is contraindicated in hemodynamically unstable patients.

Question 6345

Topic: 2. Trauma

A 30-year-old woman undergoes closed reduction and percutaneous pinning of a Hawkins type II talar neck fracture. At her 8-week follow-up appointment, an anteroposterior radiograph of the ankle reveals a subchondral radiolucent band extending across the dome of the talus. What is the clinical significance of this radiographic finding?

. It indicates early onset of avascular necrosis (AVN)
. It is a highly reliable indicator that the talar body remains vascularized
. It signifies an impending nonunion at the talar neck fracture site
. It is pathognomonic for post-traumatic osteoarthritis
. It suggests an unrecognized osteochondral defect of the talar dome

Correct Answer & Explanation

. It is a highly reliable indicator that the talar body remains vascularized

Explanation

The radiographic finding described is known as the 'Hawkins sign'. It consists of a subchondral radiolucent band in the talar dome typically seen 6 to 8 weeks after a talar neck fracture. This radiolucency represents subchondral osteopenia, which occurs as a result of disuse atrophy. For this bone resorption to happen, the talar body must have an intact blood supply. Therefore, the presence of a positive Hawkins sign is a highly reliable indicator that the talar body remains vascularized and has not undergone avascular necrosis (AVN).

Question 6346

Topic: 2. Trauma

A 28-year-old man is brought to the trauma center following a severe motor vehicle accident. On physical examination, his left upper extremity is flail, pale, and completely pulseless. Radiographs reveal massive lateral displacement of the left scapula, an intact clavicle, and complete disruption of the acromioclavicular joint. Which of the following associated injuries carries the highest risk of acute mortality in this patient?

. Complete brachial plexus avulsion
. Subclavian or axillary artery disruption
. Tension pneumothorax
. Cervical spine fracture
. Massive rotator cuff avulsion

Correct Answer & Explanation

. Subclavian or axillary artery disruption

Explanation

This clinical presentation is classic for scapulothoracic dissociation, a severe injury resulting from massive traction force to the shoulder girdle. It is characterized by lateral displacement of the scapula with an intact clavicle or clavicular fracture, and disruption of the AC or SC joint. While complete brachial plexus avulsions are extremely common and cause severe long-term morbidity, the highest risk of acute mortality is due to concomitant disruption of the subclavian or axillary vessels, which can lead to rapid, life-threatening exsanguination.

Question 6347

Topic: 2. Trauma

A 68-year-old woman with a history of osteoporosis treated with alendronate for the past 10 years presents with 3 months of progressive, severe right thigh pain worsened by weight-bearing. Plain radiographs show cortical thickening of the lateral cortex of the right subtrochanteric femur with a visible transverse radiolucent line. What is the most appropriate management of this patient's condition?

. Immediate discontinuation of alendronate and weight-bearing as tolerated
. Discontinuation of alendronate and physical therapy
. Prophylactic intramedullary nailing of the right femur
. Core decompression of the subtrochanteric femur
. Open reduction and internal fixation with a dynamic hip screw

Correct Answer & Explanation

. Prophylactic intramedullary nailing of the right femur

Explanation

The patient's history of long-term bisphosphonate use, prodromal thigh pain, and radiographic findings of lateral cortical thickening with a transverse radiolucent line are characteristic of an incomplete atypical femur fracture. Because the patient is highly symptomatic and has a visible radiolucent line indicating a stress fracture, the lesion is at very high risk of progressing to a complete, displaced fracture. The standard of care for a symptomatic incomplete atypical femur fracture is prophylactic intramedullary nailing.

Question 6348

Topic: 2. Trauma

A 35-year-old man undergoes reamed intramedullary nailing for a closed diaphyseal tibia fracture. Twelve hours postoperatively, he complains of severe leg pain that is completely out of proportion to his injury and is unresponsive to escalating doses of intravenous opioids. On examination, he experiences severe pain upon passive flexion of his great toe. This finding specifically suggests compartment syndrome involving which of the following compartments of the leg?

. Anterior compartment
. Lateral compartment
. Superficial posterior compartment
. Deep posterior compartment
. Peroneal compartment

Correct Answer & Explanation

. Anterior compartment

Explanation

Pain out of proportion to the injury and increased pain with passive stretch of the muscles within a compartment are the hallmark clinical signs of acute compartment syndrome. Passive flexion of the great toe stretches the extensor hallucis longus (EHL) muscle. The EHL, along with the tibialis anterior, extensor digitorum longus, and peroneus tertius, resides in the anterior compartment of the lower leg. Thus, pain on passive great toe flexion indicates anterior compartment ischemia.

Question 6349

Topic: 2. Trauma

A 28-year-old polytrauma patient presents to the emergency department after a high-speed motorcycle collision. He has bilateral closed femoral shaft fractures, severe pulmonary contusions, and a traumatic brain injury. His initial vital signs include a blood pressure of 85/50 mm Hg and a heart rate of 125 bpm. Laboratory studies reveal a lactate of 5.5 mmol/L, pH 7.20, and base excess of -8 mmol/L. According to the principles of damage control orthopedics (DCO), what is the most appropriate initial management of his bilateral femur fractures?

. Bilateral reamed intramedullary nailing
. Bilateral external fixation
. Unilateral reamed intramedullary nailing and contralateral external fixation
. Bilateral skeletal traction
. Bilateral plate osteosynthesis

Correct Answer & Explanation

. Bilateral external fixation

Explanation

Damage control orthopedics (DCO) is indicated in polytrauma patients who are physiologically unstable or 'in extremis'. Objective parameters indicating physiological exhaustion include pH < 7.25, base excess < -5.5 mmol/L, serum lactate > 2.5 mmol/L, and hypothermia (< 35°C). Performing early total care (e.g., bilateral reamed intramedullary nailing) in this patient exposes him to a massive 'second hit' of systemic inflammation, significantly increasing the risk of acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), and death. Therefore, rapid, temporary stabilization with external fixation is the standard of care to control hemorrhage and restore bone length without overwhelming the patient's physiologic reserves.

Question 6350

Topic: 2. Trauma

A 24-year-old man sustains a closed fracture of the middle third of the humeral shaft during an arm-wrestling match. On physical examination, he is unable to actively extend his wrist or fingers, and has decreased sensation over the dorsal first web space of the ipsilateral hand. Radiographs confirm a transverse midshaft humerus fracture. What is the most appropriate initial management?

. Immediate surgical exploration and primary nerve repair
. Open reduction and internal fixation with simultaneous nerve exploration
. Coaptation splinting and clinical observation
. Immediate electromyography (EMG) and nerve conduction studies
. Application of a hanging arm cast

Correct Answer & Explanation

. Coaptation splinting and clinical observation

Explanation

Primary radial nerve palsy occurs in up to 18% of closed humeral shaft fractures. The vast majority (70-90%) of these injuries represent neurapraxia and will recover spontaneously within 3 to 4 months. Therefore, the standard initial management for a closed humerus fracture with a primary radial nerve palsy is nonoperative treatment using a coaptation splint or functional brace. Immediate surgical exploration is generally reserved for open fractures, severe soft tissue compromise, vascular injury, or secondary palsy (loss of radial nerve function that occurs after a closed reduction attempt). A hanging arm cast is relatively contraindicated for transverse fractures due to the risk of fracture distraction leading to nonunion. EMG is usually not indicated until 3 to 4 weeks post-injury if no clinical recovery is observed.

Question 6351

Topic: 2. Trauma

A 30-year-old man sustains a low-velocity gunshot wound to the right leg. Radiographs reveal a comminuted midshaft tibia fracture. There is a 1-cm entrance wound on the anteromedial aspect of the leg and no exit wound. The bullet is lodged in the deep posterior compartment soft tissues. Distal pulses are strong, and compartment compartments are soft and compressible. What is the most appropriate initial management of the wound and fracture?

. Intravenous cefazolin for 24 hours, bedside local wound care, and intramedullary nailing
. Intravenous cefazolin for 24 hours, formal operating room debridement with bullet extraction, and external fixation
. Intravenous cefazolin and gentamicin, formal operating room debridement, and intramedullary nailing
. Intravenous antibiotics for 7 days, formal operating room debridement, and circular frame application
. No systemic antibiotics, bedside local wound care, and long leg casting

Correct Answer & Explanation

. Intravenous cefazolin for 24 hours, bedside local wound care, and intramedullary nailing

Explanation

Low-velocity gunshot wounds (GSWs) causing long bone fractures are generally managed similarly to Gustilo-Anderson Type I or II open fractures. The bullet itself does not necessarily drag vast amounts of contaminated debris into the wound, and extensive formal operating room debridement is not routinely indicated unless the wound is grossly contaminated, there is substantial devitalized tissue, or the bullet is intra-articular. Standard treatment includes superficial local wound care in the emergency department, 24 hours of a first-generation cephalosporin (e.g., cefazolin), and standard fracture stabilization. For a length-unstable, comminuted midshaft tibia fracture, reamed intramedullary nailing is the treatment of choice. Routine bullet extraction from soft tissues is unnecessary and may cause further iatrogenic injury.

Question 6352

Topic: 2. Trauma
A 45-year-old male is brought to the trauma bay after being crushed by heavy machinery. His pelvis is unstable to manual compression, and radiographs confirm an anteroposterior compression (APC-III) pelvic ring injury. During the secondary survey, he complains of a severe inability to void, and the examining physician notes blood at the urethral meatus. What is the next most appropriate step in the evaluation of his urologic injury?
. Immediate insertion of a standard Foley catheter
. Retrograde urethrogram
. Computed tomography (CT) cystogram
. Intravenous pyelogram
. Bedside flexible cystoscopy

Correct Answer & Explanation

. Retrograde urethrogram

Explanation

In a patient with a high-energy pelvic ring injury, the presence of blood at the urethral meatus, a high-riding or non-palpable prostate on digital rectal examination, or a scrotal/perineal hematoma is highly suspicious for a urethral injury. Attempting to insert a standard Foley catheter in this setting is absolutely contraindicated as it may convert a partial urethral tear into a complete transection. The mandatory next diagnostic step is a retrograde urethrogram (RUG). Once the urethra is confirmed to be intact via RUG, a bladder catheter can be safely placed. If a urethral tear is identified, urology consultation for a suprapubic catheter is typically required.

Question 6353

Topic: 2. Trauma
A 52-year-old farmer sustains an open tibial shaft fracture after his leg becomes entangled in an agricultural tiller. In the emergency department, the wound measures 12 cm in length with significant muscle crush injury, periosteal stripping, and visible heavy soil and manure contamination. According to classic evidence-based guidelines for open fractures, what is the most appropriate initial intravenous antibiotic regimen for this patient?
. Cefazolin alone
. Cefazolin and gentamicin
. Cefazolin, gentamicin, and high-dose penicillin
. Clindamycin and levofloxacin
. Vancomycin and ceftriaxone

Correct Answer & Explanation

. Cefazolin, gentamicin, and high-dose penicillin

Explanation

The classic management of open fractures relies on the Gustilo-Anderson classification to guide antibiotic therapy. Type I and II fractures are typically treated with a first-generation cephalosporin (e.g., cefazolin). Type III fractures require broader coverage, classically achieved by adding an aminoglycoside (e.g., gentamicin) to cover Gram-negative organisms. In situations involving heavy soil contamination, farm-related injuries, or potential bowel contamination, high-dose penicillin is added to provide explicit coverage against Clostridium species, which are responsible for gas gangrene. While modern institutional protocols sometimes substitute these with ceftriaxone and metronidazole, the classic board-tested regimen for a heavily contaminated farm injury remains a first-generation cephalosporin, an aminoglycoside, and penicillin.

Question 6354

Topic: Pelvic & Acetabular Trauma

A 35-year-old male is brought to the ED after a motorcycle crash. His blood pressure is 80/40 mmHg and heart rate is 120 bpm. Primary survey reveals an unstable pelvis. A pelvic binder is applied. Which of the following is the most appropriate anatomical landmark for the correct placement of a pelvic binder to optimize reduction and control hemorrhage?

. Iliac crests
. Greater trochanters
. Anterior superior iliac spines
. Symphysis pubis
. Ischial tuberosities

Correct Answer & Explanation

. Greater trochanters

Explanation

Pelvic binders should be placed centered over the greater trochanters to effectively close the pelvic volume and stabilize the pelvic ring. Placement over the iliac crests is a common error and fails to adequately close the symphysis.

Question 6355

Topic: 2. Trauma

A 35-year-old hypotensive male is brought to the emergency department after a motorcycle collision. Radiographs demonstrate an 'open-book' pelvic ring injury. In the trauma bay, a circumferential pelvic binder is applied. To most effectively reduce the pelvic volume and stabilize the fracture, the binder should be centered over which of the following anatomic landmarks?

. The iliac crests
. The anterior superior iliac spines
. The greater trochanters
. The level of the umbilicus
. Just superior to the pubic symphysis

Correct Answer & Explanation

. The greater trochanters

Explanation

Pelvic binders are most effective in reducing pelvic volume when centered directly over the greater trochanters. Placement over the iliac crests is less effective and may inadvertently increase the pelvic volume or exacerbate the deformity.

Question 6356

Topic: 2. Trauma
A 40-year-old farmer sustains a Gustilo-Anderson Grade IIIB open tibial shaft fracture with severe soil and fecal contamination following a tractor rollover. According to current orthopedic trauma guidelines, what is the most appropriate initial prophylactic antibiotic regimen?
. Intravenous cefazolin only
. Intravenous ceftriaxone and vancomycin
. Intravenous cefazolin, an aminoglycoside, and high-dose penicillin
. Intravenous clindamycin
. Oral ciprofloxacin and amoxicillin-clavulanate

Correct Answer & Explanation

. Intravenous cefazolin, an aminoglycoside, and high-dose penicillin

Explanation

For Grade III open fractures with severe organic/agricultural contamination, guidelines recommend a first-generation cephalosporin, an aminoglycoside for gram-negative coverage, and penicillin to cover anaerobic organisms such as Clostridium species.

Question 6357

Topic: 2. Trauma

A 25-year-old male is admitted with a highly comminuted tibial shaft fracture. Twelve hours later, he complains of severe leg pain out of proportion to the injury, unrelieved by opioids. Passive stretch of the toes exacerbates the pain. Which of the following pressure measurements is the most reliable threshold for diagnosing acute compartment syndrome?

. Mean arterial pressure minus compartment pressure < 30 mmHg
. Systolic blood pressure minus compartment pressure < 30 mmHg
. Diastolic blood pressure minus compartment pressure < 30 mmHg
. Absolute compartment pressure > 20 mmHg
. Absolute compartment pressure > 25 mmHg

Correct Answer & Explanation

. Diastolic blood pressure minus compartment pressure < 30 mmHg

Explanation

A 'delta pressure' (diastolic blood pressure minus the measured compartment pressure) of less than 30 mmHg is considered the most reliable objective diagnostic threshold for acute compartment syndrome.

Question 6358

Topic: 2. Trauma

A 28-year-old woman sustains a displaced femoral neck fracture. Which of the following factors has been shown in the literature to be the most significant predictor for the development of avascular necrosis (AVN) of the femoral head in young adults?

. Time from injury to surgical fixation greater than 6 hours
. The initial degree of fracture displacement
. The choice of internal fixation device (screws vs. sliding hip screw)
. The use of an open versus closed reduction technique
. The presence of a capsular hematoma

Correct Answer & Explanation

. The initial degree of fracture displacement

Explanation

The initial magnitude of fracture displacement is the most critical predictor for the development of AVN in young patients with femoral neck fractures. While early fixation is recommended, recent literature suggests time to surgery has less impact on AVN rates than the initial traumatic insult.

Question 6359

Topic: 2. Trauma

A polytrauma patient presents with bilateral closed femur fractures, a severe closed head injury, and bilateral pulmonary contusions. On admission, arterial blood gas reveals a base deficit of 9 mEq/L and a lactate of 4.5 mmol/L. What is the most appropriate initial management of the femur fractures?

. Bilateral reamed intramedullary nailing
. Bilateral external fixation
. One side reamed intramedullary nailing and the other external fixation
. Bilateral skeletal traction and delayed operative intervention
. Immediate open reduction and internal fixation with plates

Correct Answer & Explanation

. Bilateral external fixation

Explanation

This patient is 'borderline' or 'in extremis' based on the severe base deficit, elevated lactate, head injury, and pulmonary contusions. Damage control orthopedics (DCO) using bilateral external fixation minimizes the systemic 'second hit' of prolonged surgery and reaming.

Question 6360

Topic: 2. Trauma

A 45-year-old man sustains a severe pelvic crush injury. Clinical examination reveals a large, fluctuant, soft-tissue mass overlying the greater trochanter. What is the pathophysiology of this specific soft-tissue injury?

. Ischemic muscular necrosis due to compartment syndrome
. Closed degloving from shearing of subcutaneous tissue away from the underlying fascia
. Massive subperiosteal hematoma following a greater trochanteric fracture
. Formation of an acute traumatic arteriovenous fistula
. Spontaneous rupture of the gluteus medius tendon

Correct Answer & Explanation

. Closed degloving from shearing of subcutaneous tissue away from the underlying fascia

Explanation

A Morel-Lavallee lesion is a closed degloving injury caused by severe shearing forces that separate the skin and subcutaneous fat from the underlying fascial layer, creating a potential space that fills with blood and lymphatic fluid.

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