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2. Trauma MCQs

Practice Set 284 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 5661

Topic: 2. Trauma

A 40-year-old skier sustains a Schatzker Type II (split-depressed) fracture of the lateral tibial plateau. Which of the following is the most commonly associated soft tissue injury that must be evaluated and potentially addressed?

. Popliteal artery intimal tear
. Common peroneal nerve neuropraxia
. Lateral meniscus tear
. Posterior cruciate ligament rupture
. Medial collateral ligament avulsion

Correct Answer & Explanation

. Lateral meniscus tear

Explanation

Schatzker Type II fractures (split-depressed fractures of the lateral tibial plateau) are highly associated with lateral meniscal tears, which can become trapped in the fracture site. Schatzker IV (medial plateau) and higher-energy variants have a higher association with neurovascular (popliteal artery, peroneal nerve) injuries.

Question 5662

Topic: Pelvic & Acetabular Trauma

A 22-year-old collegiate hockey player presents with chronic groin pain exacerbated by hip flexion, adduction, and internal rotation. Imaging demonstrates a lack of femoral head-neck offset, presenting as a 'pistol grip' deformity. This Cam-type impingement primarily damages which structure initially?

. Ligamentum teres
. Acetabular labrum at the posteroinferior quadrant
. Articular cartilage of the anterosuperior acetabulum via shear forces
. Femoral head articular cartilage via direct impaction
. Iliopsoas tendon at the pelvic brim

Correct Answer & Explanation

. Articular cartilage of the anterosuperior acetabulum via shear forces

Explanation

Cam impingement (aspherical femoral head/reduced offset) forces a non-spherical portion of the femoral head into the acetabulum during flexion. This primarily causes outside-in shear forces, leading to delamination of the anterosuperior acetabular articular cartilage, often with secondary separation of the adjacent labrum. Pincer impingement, conversely, causes direct linear compression of the labrum.

Question 5663

Topic: 2. Trauma

A 35-year-old construction worker falls 15 feet, sustaining a high-energy distal tibia fracture extending into the plafond with significant soft tissue swelling and fracture blisters. Which of the following surgical strategies is most widely accepted as the standard of care to minimize soft tissue complications in this specific injury pattern?

. Immediate single-stage open reduction and internal fixation of the tibia and fibula
. Primary arthrodesis of the tibiotalar joint
. Immediate spanning external fixation with delayed definitive internal fixation of the tibia
. Immediate reamed intramedullary nailing of the tibia with percutaneous articular screws
. Immediate circular fine-wire frame application as definitive single-stage treatment

Correct Answer & Explanation

. Immediate spanning external fixation with delayed definitive internal fixation of the tibia

Explanation

High-energy pilon fractures are notorious for severe soft-tissue compromise. The standard of care to minimize devastating wound complications (such as dehiscence and deep infection) is a staged protocol: initial spanning external fixation to restore length and alignment, allowing the soft-tissue envelope to recover (e.g., return of skin wrinkles), followed by delayed definitive ORIF 1-3 weeks later.

Question 5664

Topic: 2. Trauma

A 42-year-old man sustains a closed spiral fracture of the middle third of the humeral shaft (Holstein-Lewis type). He has an immediate complete radial nerve palsy on presentation. He is treated non-operatively in a functional fracture brace. At 12 weeks post-injury, there is no clinical recovery, and an electromyogram (EMG) shows no signs of reinnervation. What is the most appropriate next step in management?

. Continue bracing and repeat EMG in 3 months
. Surgical exploration of the radial nerve
. Immediate tendon transfers for wrist and finger extension
. Open reduction and internal fixation of the humerus
. Ultrasound-guided corticosteroid injection around the radial nerve

Correct Answer & Explanation

. Surgical exploration of the radial nerve

Explanation

Primary radial nerve palsy in the setting of a closed humerus fracture is usually a neuropraxia and observed initially. However, if there are no clinical or electromyographic (EMG) signs of recovery by 12-16 weeks, surgical exploration of the nerve is indicated to assess for transection, entrapment, or severe neuroma requiring grafting/repair.

Question 5665

Topic: 2. Trauma
A 28-year-old male sustains a vertically oriented, displaced basicervical femoral neck fracture (Pauwels Type III). He undergoes open reduction and internal fixation. Which of the following biomechanical forces across the fracture site is the primary cause of fixation failure and nonunion in this specific fracture pattern?
. Axial compression
. Anterior translation
. Shear stress
. Tension on the medial calcar
. Rotational torque

Correct Answer & Explanation

. Shear stress

Explanation

Pauwels Type III fractures are characterized by a highly vertical fracture line (angle > 50 degrees to the horizontal). This vertical orientation converts joint reactive forces primarily into extreme shear forces at the fracture site, which promotes varus displacement and nonunion, making it biomechanically the most challenging femoral neck fracture to stabilize.

Question 5666

Topic: 2. Trauma
A 32-year-old male undergoes reamed intramedullary nailing for a closed tibial shaft fracture. In the recovery room, he complains of severe, escalating pain out of proportion to the injury. The clinical exam is equivocal due to a regional block. Compartment pressures are measured. Which of the following parameter thresholds is the most reliable indicator for acute compartment syndrome?
. Absolute compartment pressure > 20 mmHg
. Diastolic blood pressure minus compartment pressure ≤ 30 mmHg
. Mean arterial pressure minus compartment pressure ≤ 45 mmHg
. Absolute compartment pressure > 25 mmHg
. Systolic blood pressure minus compartment pressure ≤ 30 mmHg

Correct Answer & Explanation

. Diastolic blood pressure minus compartment pressure ≤ 30 mmHg

Explanation

The diagnosis of acute compartment syndrome relies on the perfusion pressure of the limb. A delta pressure (Diastolic Blood Pressure minus Compartment Pressure) of less than or equal to 30 mmHg is the most reliable and widely accepted diagnostic threshold for acute compartment syndrome, as it accounts for patient-specific hemodynamic variations better than an absolute pressure cutoff.

Question 5667

Topic: Pelvic & Acetabular Trauma
A 45-year-old male presents after a motorcycle collision with a radiographically confirmed anteroposterior compression type II (APC II) pelvic ring injury. Which of the following ligamentous structures is typically intact in this specific injury pattern?
. Symphyseal ligaments
. Anterior sacroiliac ligaments
. Sacrospinous ligaments
. Sacrotuberous ligaments
. Posterior sacroiliac ligaments

Correct Answer & Explanation

. Posterior sacroiliac ligaments

Explanation

In the Young-Burgess classification, an APC II pelvic ring injury involves diastasis of the pubic symphysis (rupture of symphyseal ligaments) and 'opening of the book' at the SI joint. This mechanism ruptures the anterior sacroiliac, sacrospinous, and sacrotuberous ligaments. However, the stout posterior sacroiliac ligaments remain intact, acting as a hinge. Complete disruption of the posterior SI ligaments would convert this to a completely unstable APC III injury.

Question 5668

Topic: 2. Trauma

A 24-year-old male sustains a proximal pole scaphoid fracture. The high risk of avascular necrosis in this region is primarily due to the retrograde blood supply originating from branches of which artery?

. Radial artery
. Ulnar artery
. Anterior interosseous artery
. Posterior interosseous artery
. Deep palmar arch

Correct Answer & Explanation

. Radial artery

Explanation

The scaphoid is predominantly supplied by the radial artery. The major vascular supply enters the scaphoid distally (at the dorsal ridge) and flows in a retrograde fashion toward the proximal pole. Because of this tenuous retrograde blood supply, fractures at the waist or proximal pole of the scaphoid disrupt the vascular flow, leaving the proximal fragment at a very high risk of nonunion and avascular necrosis.

Question 5669

Topic: 2. Trauma

A 28-year-old male sustains a closed comminuted tibial shaft fracture. Twelve hours post-injury, he complains of excruciating pain out of proportion to the injury, not relieved by intravenous opioids. His foot is warm with palpable dorsalis pedis and posterior tibial pulses. Which of the following physical exam findings is the most sensitive early clinical indicator of acute compartment syndrome?

. Loss of palpable pedal pulses
. Pallor of the distal extremity
. Pain with passive stretch of the toes
. Motor paralysis of the extensor hallucis longus
. Capillary refill time greater than 3 seconds

Correct Answer & Explanation

. Pain with passive stretch of the toes

Explanation

Acute compartment syndrome is a surgical emergency characterized by tissue pressure exceeding capillary perfusion pressure. The classic '6 Ps' are pain, pallor, paresthesia, pulselessness, paralysis, and poikilothermia. However, pain out of proportion to the injury and pain with passive stretch of the muscles within the affected compartment are the earliest and most sensitive clinical signs. Pulselessness and paralysis are very late findings and indicate irreversible ischemic damage; pulses often remain intact until very late because arterial pressure is much higher than compartment pressure.

Question 5670

Topic: 2. Trauma

A 55-year-old female falls on an outstretched hand and sustains a distal radius fracture. Radiographs show a fracture of the volar rim of the distal radius with volar subluxation of the carpus alongside the fracture fragment. This fracture pattern is best classified as:

. Colles fracture
. Smith fracture
. Volar Barton fracture
. Chauffeur's fracture
. Die-punch fracture

Correct Answer & Explanation

. Volar Barton fracture

Explanation

A volar Barton fracture is an intra-articular fracture of the distal radius involving the volar rim, accompanied by volar subluxation or dislocation of the carpus. It represents a radiocarpal fracture-dislocation. A Colles fracture is an extra-articular fracture with dorsal angulation/displacement, while a Smith fracture is an extra-articular fracture with volar angulation. A Chauffeur's fracture involves the radial styloid, and a die-punch fracture is an intra-articular fracture of the lunate fossa.

Question 5671

Topic: 2. Trauma
A 65-year-old male sustains a proximal humerus fracture after a fall. According to the Hertel criteria, which of the following radiographic features is the most reliable predictor of humeral head ischemia?
. Metaphyseal head extension > 5 mm
. Calcar length < 8 mm
. Intact medial hinge
. Varus angulation > 20 degrees
. Greater tuberosity displacement > 1 cm

Correct Answer & Explanation

. Calcar length < 8 mm

Explanation

Hertel et al. described radiographic predictors of humeral head ischemia. The best predictors are a short calcar segment attached to the articular surface (calcar length < 8 mm), disrupted medial hinge, and a basicervical fracture line. A metaphyseal extension > 8 mm (not 5 mm) attached to the head actually predicts a better blood supply (lower risk of ischemia), whereas a shorter segment (< 8 mm) indicates higher risk of ischemia.

Question 5672

Topic: 2. Trauma

During an anterolateral approach to the distal tibia for open reduction and internal fixation of a pilon fracture, the superficial dissection puts a specific nerve at significant risk.

Which nerve crosses the operative field from lateral to medial and must be carefully identified and protected?

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

Correct Answer & Explanation

. Superficial peroneal nerve

Explanation

The superficial peroneal nerve provides sensation to the dorsum of the foot. In the distal third of the leg, it emerges from the lateral compartment, pierces the crural fascia, and courses anteriorly over the fibula and distal tibia, putting it at direct risk during the superficial dissection of the anterolateral approach to the pilon/distal tibia.

Question 5673

Topic: 2. Trauma
A 28-year-old male sustains a high-energy Pauwels type III femoral neck fracture. If this fracture is treated with three parallel cancellous lag screws alone, what biomechanical force is the primary reason for a high rate of fixation failure?
. High tensile forces along the inferior neck
. High vertical shear forces
. Torsional instability during swing phase
. Distraction forces from the abductor musculature
. Implant pullout secondary to focal osteopenia

Correct Answer & Explanation

. High vertical shear forces

Explanation

Pauwels classification of femoral neck fractures is based on the angle of the fracture line relative to the horizontal plane. A Pauwels type III fracture is characterized by an angle > 50 degrees (a more vertically oriented fracture line). This orientation converts compressive forces into very high vertical shear forces across the fracture site, which frequently leads to displacement and failure if treated with parallel cancellous screws alone. Fixed-angle constructs (like a sliding hip screw) are favored to resist these shear forces.

Question 5674

Topic: 2. Trauma

A 17-year-old high school track athlete has had progressive midfoot pain for the past 3 weeks that prevents him from running. Examination reveals pain over the tarsal navicular. Radiographs are normal, but a CT scan reveals a nondisplaced sagittally oriented fracture line. Management should consist of

. an orthosis and an immediate return to running.
. no running for 6 weeks and use of a bone stimulator at night.
. a University of California Biomechanics Laboratory (UCBL) orthosis and a gradual return to running.
. immobilization in a short leg cast with no weight bearing for 6 to 8 weeks.
. open reduction and internal fixation.

Correct Answer & Explanation

. immobilization in a short leg cast with no weight bearing for 6 to 8 weeks.

Explanation

The patient has a nondisplaced stress fracture of the tarsal navicular. Weight bearing is associated with a high rate of nonunion; therefore, management should consist of immobilization and no weight bearing for 8 weeks. Delayed union or nonunion is treated by excision of sclerotic fracture margins and bone grafting, with or without internal fixation. Generally, CT should be repeated to document healing before permitting a return to sports. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 597-612.

Question 5675

Topic: 2. Trauma
A 30-year-old man is brought to the emergency department after a motor vehicle accident. He has a closed midshaft femoral fracture and an intra-abdominal injury. He is currently in the operating room and the exploration of his abdomen has been completed. His initial blood pressure was 70/30 mm Hg and is now 90/50 mm Hg after 4 liters of fluid and 2 units of blood. His initial serum lactate was 3.0 mmol/L (normal < 2.5), 1 hour postinjury it was 3.5 mmol/L, and it is now 5 mmol/L. His core temperature is 93 degrees F (34 degrees C). What is the most appropriate management for the femoral shaft fracture at this point?
. Reamed intramedullary nailing
. Traction
. External fixation
. Open plating
. Mast suit

Correct Answer & Explanation

. External fixation

Explanation

The patient has several indications that he is not ready for definitive fixation of the femoral shaft fracture at this point. He is cold with a core temperature of 93 degrees F, and hypothermia of less than 95 degrees F (35 degrees C) has been shown to be associated with an increased mortality rate in trauma patients. The patient has also not been resuscitated based on his increasing lactate levels and although controversial, it has been shown that temporary external fixation leads to a lower incidence of multiple organ failure and acute respiratory distress syndrome.

Question 5676

Topic: 2. Trauma

A 19-year-old woman fell onto her nondominant hand 6 weeks ago. Radiographs are shown in Figures 37a and 37b. A decision has been made to treat this fracture surgically. What is the best approach to treat this fracture?

. Percutaneous pinning of the fracture with Kirschner wires
. Open reduction and pinning with Kirschner wires
. Arthroscopic in situ compression screw fixation
. Reduction and compression screw fixation via a volar approach
. Reduction and compression screw fixation via a dorsal approach

Correct Answer & Explanation

. Reduction and compression screw fixation via a dorsal approach

Explanation

Displaced fractures of the scaphoid are best treated with compression screw fixation. Proximal third fractures (as in this patient) are optimally approached via a dorsal approach to ensure proper reduction and compression. Fractures of the scaphoid waist can be approached either by a volar or a dorsal approach. Kirschner wire fixation is limited to proximal pole fractures that are too small to accommodate the trailing head of a compression screw. Retting ME, Raskin KB: Retrograde compression screw fixation of acute proximal pole fractures. J Hand Surg Am 1999;24:1206-1210.

Question 5677

Topic: 2. Trauma

Figures 38a and 38b show the AP and lateral radiographs of a 12-year-old baseball pitcher who has pain in his right dominant elbow. Management should consist of

. gentle range of motion and ultrasound.
. cast immobilization and a bone stimulator.
. elimination of offending activities and cross-training.
. arthroscopy with excision of the pathologic portion.
. MRI for assessment of accompanying ligamentous instability.

Correct Answer & Explanation

. elimination of offending activities and cross-training.

Explanation

The patient has a stress fracture of the olecranon; therefore, the most appropriate management is modification of activities below the threshold of symptoms to allow for healing. Ultrasound provides no benefit, and immobilization is not necessary. MRI is not necessary because there is no associated ligamentous injury. Arthroscopy is not indicated. Cabanela ME, Morrey BF: Fractures of the olecranon, in Morrey BF (ed): The Elbow and Its Disorders. Philadelphia, PA, WB Saunders, 2000, pp 365-379.

Question 5678

Topic: 2. Trauma

A 19-year-old man sustained the isolated injury seen in Figure 28a. He is adequately resuscitated. A closed reduction was performed in the emergency department, and postreduction radiographs are shown in Figures 28b and 28c. What is the next most appropriate step in management?

. Urgent open reduction and internal fixation
. Placement of a knee immobilizer and delayed open reduction and internal fixation
. Placement of a distal femoral traction pin and delayed open reduction and internal fixation
. Delayed open reduction and internal fixation
. Nonsurgical management and restricted weight bearing

Correct Answer & Explanation

. Urgent open reduction and internal fixation

Explanation

Incarcerated fragments and nonconcentric reductions are best treated with urgent open reduction, retrieval of the fragments, and internal fixation. Delayed treatment increases the damage to the articular surface, even if traction is applied. There is no role for nonsurgical management with entrapped fragments and nonconcentric reduction of the hip. Epstein HC, Wiss DA, Cozen L: Posterior fracture dislocation of the hip with fractures of the femoral head. Clin Orthop Relat Res 1985;201:9-17.

Question 5679

Topic: 2. Trauma

A 13-year-old girl sustained an isolated midshaft left femoral fracture in a motor vehicle accident. The fracture was treated with a rigid, antegrade intramedullary nail placed through the piriformis fossa. The fracture healed uneventfully, as shown in Figure 46a; however, at 12 months postoperatively she now reports left hip pain. A current AP radiograph and MRI scan are shown in Figures 46b and 46c. What complication occurred in this patient?

. Chondrolysis
. Ischemic necrosis of the femoral head
. Ischemic necrosis of the greater trochanter
. Femoral neck fracture
. Trochanteric overgrowth

Correct Answer & Explanation

. Ischemic necrosis of the femoral head

Explanation

The development of femoral head ischemic necrosis is the iatrogenically created complication in this skeletally immature patient. Placement of a rigid, antegrade intramedullary nail through the piriformis fossa is likely to damage the vascular supply to the femoral head as the vessels ascend the femoral neck on the way to the femoral head. The MRI scan reveals ischemic necrosis with early collapse of the femoral head. The joint space is preserved on the MRI scan, ruling out chondrolysis. Letts M, Jarvis J, Lawton L, et al: Complications of rigid intramedullary rodding of femoral shaft fractures in children. J Trauma 2002;52:504-516. Buckley SL: Current trends in the treatment of femoral shaft fractures in children and adolescents. Clin Orthop Relat Res 1997;338:60-73.

Question 5680

Topic: 2. Trauma

A 28-year-old female firefighter fell from the top of a three-story building in the line of duty. She sustained a displaced pelvic fracture with more than 5 mm displacement. Compared to normal healthy controls, these patients have a higher incidence of

Trauma 2009 Practice Questions: Set 3 (Solved) - Figure 14

. normal sexual function and normal vaginal childbirth.
. sexual dysfunction (dyspareunia) and normal vaginal childbirth.
. normal sexual function and caesarean section childbirth.
. sexual dysfunction (dyspareunia) and caesarean section childbirth.
. normal sexual function and caesarean section childbirth until hardware removal.

Correct Answer & Explanation

. sexual dysfunction (dyspareunia) and caesarean section childbirth.

Explanation

Pelvic trauma in women has been shown to increase the risk of sexual dysfunction and dyspareunia. Additionally, caesarean section childbirth is almost universal following pelvic trauma regardless of whether anterior pelvic hardware is present or not. Copeland CE, Bosse MJ, McCarthy ML et al: Effect of trauma and pelvic fracture on female genitourinary, sexual, and reproductive function. J Orthop Trauma 1997;11:73-81.

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