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2. Trauma MCQs

Practice Set 223 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 4441

Topic: 2. Trauma
A 12-year-old boy with hemophilia A and no known inhibitors sustains a tibia fracture and has pain with passive motion of the deep toe flexors. Appropriate management should consist of
. emergency fasciotomy, followed by factor VIII replacement.
. cryoprecipitate, followed by assessment of compartment pressures.
. factor VIII replacement, followed by assessment of compartment pressures.
. physical therapy to prevent contractures.
. splinting, ice, and elevation.

Correct Answer & Explanation

. factor VIII replacement, followed by assessment of compartment pressures.

Explanation

In a patient with hemophilia, factor replacement followed by assessment of compartment pressures is essential. If the patient has inhibitors, the problem is more difficult. Porcine factor has been helpful in patients with inhibitory antibodies. Recent evidence points to using activated factor VII and bypassing the intrinsic pathway. Desmopressin is an adjunct to therapy but is not as effective as factor VII.

Question 4442

Topic: 2. Trauma

A 22-year-old female collegiate soccer player sustains a non-contact twisting injury to her right knee and feels a 'pop'. Radiographic evaluation is obtained in the emergency department as shown below.

Based on the pathognomonic radiographic finding, which of the following injury mechanisms most accurately describes the etiology of the associated primary ligamentous pathology?

. Valgus stress with internal tibial rotation
. Varus stress with internal tibial rotation
. Hyperextension with direct anterior tibial translation
. Direct blow to the lateral aspect of the knee with the foot planted
. Hyperflexion with posterior tibial translation

Correct Answer & Explanation

. Valgus stress with internal tibial rotation

Explanation

The clinical scenario and the likely presence of a Segond fracture (an avulsion fracture of the anterolateral proximal tibia) are pathognomonic for an anterior cruciate ligament (ACL) tear. The Segond fracture is an avulsion of the anterolateral ligament (ALL) or the lateral capsular ligamentous complex. It occurs due to internal rotation of the tibia combined with varus stress. This is frequently associated with ACL ruptures. While non-contact valgus with external rotation is a common mechanism for ACL tears, the specific Segond fracture avulsion is classically caused by internal tibial rotation and varus stress.

Question 4443

Topic: Lower Extremity Trauma

A 28-year-old female sustains a complete tear of her anterior cruciate ligament (ACL) and requires reconstruction. The pivot shift test is positive on examination. Which anatomic structure dynamically causes the visible 'clunk' or reduction of the tibia during the pivot shift maneuver as the knee is transitioned from extension to flexion?

. Medial collateral ligament
. Iliotibial band
. Popliteus tendon
. Posterior cruciate ligament
. Biceps femoris

Correct Answer & Explanation

. Iliotibial band

Explanation

The pivot shift test demonstrates dynamic rotatory instability of the ACL-deficient knee. Starting in extension with valgus and internal rotation applied, the lateral tibial plateau subluxates anteriorly. As the knee flexes past 20 to 30 degrees, the Iliotibial (IT) band transitions its orientation relative to the instantaneous center of rotation from an extensor to a flexor of the knee. This transition pulls the subluxated lateral tibial plateau posteriorly, creating the sudden reduction or 'clunk' characteristic of a positive pivot shift.

Question 4444

Topic: 2. Trauma

A 45-year-old female with a BMI of 32 presents with sudden onset posteromedial knee pain after stepping off a curb. She has no prior history of knee trauma.

MRI reveals a full-thickness radial tear of the medial meniscus at its posterior attachment to the tibia, with 4 mm of meniscal extrusion. Biomechanically, what is the consequence of this injury on the medial compartment?

. It decreases peak contact pressures by redistributing loads anteriorly
. It is biomechanically equivalent to a total meniscectomy
. It maintains hoop stresses but disrupts proprioception
. It transfers load primarily to the lateral compartment, causing lateral compartment narrowing
. It increases the stability of the anterior cruciate ligament

Correct Answer & Explanation

. It is biomechanically equivalent to a total meniscectomy

Explanation

A posterior root tear of the medial meniscus disrupts the meniscal attachment to the tibial plateau, eliminating the ability of the meniscus to convert axial loads into hoop stresses. Biomechanical studies have demonstrated that a complete root tear with associated meniscal extrusion (>3 mm) alters knee contact mechanics equivalently to a total meniscectomy, leading to significantly increased peak contact pressures and rapid progression of osteoarthritis.

Question 4445

Topic: Lower Extremity Trauma

A 40-year-old male manual laborer with symptomatic, isolated medial compartment knee osteoarthritis and a mechanical varus axis of 8 degrees is undergoing a medial opening-wedge high tibial osteotomy (HTO). To achieve optimal offloading of the diseased medial compartment without causing excessive lateral compartment overload, the mechanical axis should be corrected to pass through a specific anatomic coordinate on the tibial plateau. What is the standard target point for the mechanical axis post-correction?

. Exactly at the 50% coordinate (the center of the tibial spines)
. The Fujisawa point, located at approximately 62.5% of the tibial width (measured from medial to lateral)
. The lateral margin of the lateral meniscus (100% of tibial width)
. The medial intercondylar tubercle (40% of tibial width)
. 30% of the tibial width, keeping the axis slightly in the medial compartment

Correct Answer & Explanation

. Exactly at the 50% coordinate (the center of the tibial spines)

Explanation

The goal of a high tibial osteotomy (HTO) for medial compartment osteoarthritis in a varus knee is to shift the mechanical weight-bearing axis laterally to offload the diseased medial cartilage. The widely accepted standard target is the 'Fujisawa point', which is located at 62-62.5% of the tibial width, measured from the medial edge (0%) to the lateral edge (100%). This point lies just lateral to the lateral tibial spine. Overcorrection beyond 65-70% risks rapid degeneration of the lateral compartment, while undercorrection (<50%) fails to adequately relieve medial pain.

Question 4446

Topic: 2. Trauma

Placing a plate too anteriorly against the lateral aspect of the bicipital groove while performing open reduction and internal fixation (ORIF) of a proximal humerus fracture has an increased risk of what complication?

. Avascular necrosis
. Loss of fixation of the fracture
. Malunion leading to increased retroversion of the articular surface
. Glenoid arthrosis

Correct Answer & Explanation

. Avascular necrosis

Explanation

There are two major arteries that supply the humeral head. One is the ascending branch of the anterior humeral circumflex artery, which runs up the lateral aspect of the bicipital groove terminating in the arcuate artery. The other is the posterior humeral circumflex artery, which more recently has been demonstrated to supply a significant portion of the blood supply to the humeral head. Capsular arteries also play a role in humeral head perfusion. Care should be taken to preserve all intact arterial supply when performing ORIF, as injury to these arteries may result in avascular necrosis. In general, the most common complications of locked plating include loss of reduction with penetration of the joint by the screws, particularly with initial varus positioning of the humeral head. Placement of the plate in the position described, however, should not have an impact on any ofthe other complications noted.

Question 4447

Topic: 2. Trauma

A 45-year-old female presents with a closed trimalleolar ankle fracture. A preoperative CT scan demonstrates a posterior malleolus fracture with a large posteromedial fragment extending to the medial malleolus, consistent with a Haraguchi Type II fracture.

Which of the following surgical approaches provides the most optimal visualization and access for rigid internal fixation of this specific posterior malleolar fracture pattern?

. Standard anterior approach with anterior-to-posterior lag screws
. Isolated posterolateral approach
. Posteromedial approach
. Transfibular approach
. Standard medial approach to the medial malleolus alone

Correct Answer & Explanation

. Standard anterior approach with anterior-to-posterior lag screws

Explanation

Haraguchi classification categorizes posterior malleolus fractures based on axial CT imaging. Type I is a posterolateral oblique fragment. Type II involves a medial extension (transverse extension) that often includes the medial malleolus or is associated with a disrupted posterior colliculus. Because the fracture extends posteromedially, a posteromedial approach is required to directly visualize, reduce, and plate the fracture. An isolated posterolateral approach would not provide access to the posteromedial extension, and anterior-to-posterior screws are biologically and mechanically inferior to posterior buttress plating for these large fragments.

Question 4448

Topic: 2. Trauma

A 65-year-old male with poorly controlled type 2 diabetes mellitus and peripheral neuropathy sustains a displaced bimalleolar equivalent ankle fracture. He undergoes open reduction and internal fixation (ORIF). Which of the following postoperative regimens or fixation strategies is considered the standard of care to minimize complications in this specific patient population?

. Standard ORIF with early weight-bearing at 2 weeks
. Augmented fixation (e.g., multiple quad-cortical syndesmotic screws, locking plates) and prolonged non-weight-bearing
. Primary below-knee amputation
. Standard ORIF followed by immediate transition to a weight-bearing total contact cast
. Use of bioabsorbable fixation to reduce infection risk

Correct Answer & Explanation

. Standard ORIF with early weight-bearing at 2 weeks

Explanation

Diabetic patients, particularly those with peripheral neuropathy, are at extremely high risk for postoperative complications following ankle fracture surgery, including Charcot neuroarthropathy, infection, and hardware failure. Standard of care involves 'maximizing fixation'โ€”using locking plates, multiple quad-cortical syndesmotic screws, and sometimes extending fixation across the tibiotalar joint if the risk of failure is severe. Additionally, the period of non-weight-bearing is typically doubled compared to healthy patients, often lasting 8-12 weeks.

Question 4449

Topic: 2. Trauma

During surgical exploration of an unstable ankle fracture, the surgeon identifies an avulsion fracture of the anterior inferior tibiofibular ligament (AITFL) from its fibular attachment. This specific osseous fragment is known as:

. Tillaux-Chaput fragment
. Wagstaffe-Le Fort fragment
. Volkmann fragment
. Bosworth fragment
. Earle's fragment

Correct Answer & Explanation

. Tillaux-Chaput fragment

Explanation

The Wagstaffe-Le Fort fragment is an avulsion fracture of the anteromedial fibula at the attachment of the anterior inferior tibiofibular ligament (AITFL). The Tillaux-Chaput fragment is the corresponding avulsion from the anterolateral tibia. The Volkmann fragment is an avulsion of the posterior inferior tibiofibular ligament (PITFL) from the posterolateral tibia (often synonymous with the posterior malleolus). Bosworth refers to a fracture-dislocation where the fibula is entrapped behind the posterior tibial tubercle.

Question 4450

Topic: 2. Trauma

A 38-year-old construction worker falls from scaffolding, sustaining a high-energy closed pilon fracture (AO/OTA 43-C3) with massive soft tissue swelling, hemorrhagic fracture blisters, and shortening of the limb. What is the most appropriate initial management?

. Immediate ORIF of the tibia and fibula via dual incisions
. Immediate ORIF of the fibula and spanning external fixation of the tibia
. Primary tibiotalocalcaneal arthrodesis
. Spanning external fixation with delayed definitive ORIF of the tibia once the 'wrinkle sign' is present
. Closed reduction and long leg casting

Correct Answer & Explanation

. Immediate ORIF of the tibia and fibula via dual incisions

Explanation

The standard of care for high-energy pilon fractures with severe soft tissue compromise is a staged protocol ('span, scan, and plan'). Initial management involves the application of a joint-spanning external fixator to restore length, alignment, and allow soft tissues to recover. Definitive ORIF is delayed (typically 10-21 days) until soft tissue swelling resolves, indicated by the return of skin creases ('wrinkle sign'). While acute fibular fixation is sometimes performed, it is increasingly avoided in severe soft tissue injuries to prevent wound complications, making D the most encompassing and correct approach.

Question 4451

Topic: 2. Trauma

A surgeon is performing an anterolateral approach to the distal tibia for fixation of a complex pilon fracture. During the superficial dissection, the surgeon creates an internervous interval. Which nerve is at greatest risk of iatrogenic injury as it crosses the operative field from medial to lateral over the distal fibula/ankle joint?

. Sural nerve
. Deep peroneal nerve
. Superficial peroneal nerve
. Saphenous nerve
. Medial dorsal cutaneous nerve

Correct Answer & Explanation

. Sural nerve

Explanation

The anterolateral approach to the distal tibia typically utilizes the interval between the medial structures (tibialis anterior, extensor hallucis longus) and lateral structures (extensor digitorum longus). During the superficial dissection, branches of the superficial peroneal nerve (specifically the intermediate dorsal cutaneous branch) cross the surgical field from medial to lateral and are at high risk of transection or traction injury. The deep peroneal nerve is deeper, running with the anterior tibial artery between EHL and EDL.

Question 4452

Topic: 2. Trauma

A 35-year-old male presents after an ankle injury. Radiographs show a fracture-dislocation of the ankle. Closed reduction in the ED is unsuccessful. The lateral radiograph demonstrates the proximal fibular fragment trapped posterior to the posterior tubercle of the distal tibia.

Which of the following is the most appropriate next step in management?

. Application of a spanning external fixator
. Urgent open reduction through a posterolateral approach
. Skeletal traction via calcaneal pin
. Repeat closed reduction under general anesthesia
. CT scan to rule out talar neck fracture

Correct Answer & Explanation

. Application of a spanning external fixator

Explanation

The clinical description is of a Bosworth fracture-dislocation. The proximal fibular shaft is incarcerated behind the posterior tibial tubercle, making closed reduction impossible. Repeated attempts at closed reduction can cause further soft tissue damage and neurovascular injury. Urgent open reduction and internal fixation, usually via a posterolateral approach, is required.

Question 4453

Topic: 2. Trauma

A 42-year-old male sustains a high-energy closed pilon fracture (AO/OTA 43-C3). An ankle-spanning external fixator is applied on the day of injury.

What is the most reliable clinical indicator that the soft tissue envelope is ready for definitive open reduction and internal fixation (ORIF)?

. Decrease in swelling to pre-injury baseline
. Appearance of the "wrinkle sign" on the anterior ankle skin
. Resolution of fracture blisters
. 14 days post-injury
. Normalization of inflammatory markers (ESR, CRP)

Correct Answer & Explanation

. Decrease in swelling to pre-injury baseline

Explanation

In high-energy pilon fractures, definitive ORIF is typically delayed to allow soft tissue swelling to subside, reducing the risk of wound complications. The appearance of skin wrinkles ("wrinkle sign") is a reliable clinical indicator that the soft tissue edema has decreased sufficiently to safely proceed with surgical incisions.

Question 4454

Topic: 2. Trauma

A 28-year-old female is 8 weeks status post ORIF of a Hawkins Type II talar neck fracture. A radiograph reveals a subchondral radiolucent band in the talar dome.

What is the prognostic significance of this radiographic finding?

. It indicates a high likelihood of developing avascular necrosis (AVN)
. It represents subchondral collapse and impending osteoarthritis
. It signifies intact vascularity to the talar body
. It indicates an ongoing infection
. It is a sign of nonunion at the fracture site

Correct Answer & Explanation

. It indicates a high likelihood of developing avascular necrosis (AVN)

Explanation

The presence of a subchondral radiolucent band in the talar dome at 6 to 8 weeks post-injury is known as the Hawkins sign. This radiolucency represents subchondral osteopenia due to bone resorption, which requires an intact blood supply. Therefore, a positive Hawkins sign is a highly reliable indicator that the talar body has preserved vascularity and avascular necrosis is unlikely to occur.

Question 4455

Topic: 2. Trauma

A 50-year-old female presents with chronic ankle pain following a conservatively managed bimalleolar ankle fracture 1 year ago. Radiographs demonstrate a malunion.

Which radiographic parameter is most sensitive for detecting fibular shortening in a malunited ankle fracture?

. Talar tilt > 2 degrees
. Medial clear space > 4 mm
. Decreased talocrural angle
. Tibiofibular overlap < 10 mm
. Increased Boehler's angle

Correct Answer & Explanation

. Decreased talocrural angle

Explanation

Fibular shortening alters the ankle mortise and leads to lateral talar shift. Radiographic signs of fibular shortening include a broken Shenton's line of the ankle, a loss of the "dime sign" (unbroken curve between the lateral talar articular surface and the fibular recess), and a decreased talocrural angle (normally 83 +/- 4 degrees). The talocrural angle is the angle formed by a line perpendicular to the tibial plafond and a line connecting the tips of the medial and lateral malleoli. Fibular shortening decreases this angle.

Question 4456

Topic: 2. Trauma

A 22-year-old elite collegiate basketball player sustains a fracture at the base of the fifth metatarsal. Radiographs show a transverse fracture extending into the intermetatarsal articulation (between the 4th and 5th metatarsals).

What is the recommended treatment to minimize the risk of nonunion and expedite return to play in this athlete?

. Cast immobilization and non-weight bearing for 6-8 weeks
. Open reduction and tension band wiring
. Percutaneous intramedullary screw fixation
. Excision of the proximal fragment and reattachment of the peroneus brevis
. Corticosteroid injection followed by immediate weight-bearing in a stiff-soled shoe

Correct Answer & Explanation

. Percutaneous intramedullary screw fixation

Explanation

The fracture described is a Zone 2 fracture of the base of the 5th metatarsal (true Jones fracture), which extends into the 4th-5th intermetatarsal joint. Due to a watershed blood supply area, these have a high rate of delayed union or nonunion. In elite athletes, early intramedullary screw fixation is the standard of care as it significantly decreases the nonunion rate and allows for a faster return to sport compared to conservative management.

Question 4457

Topic: 2. Trauma

A 20-year-old track and field athlete presents with an insidious onset of vague midfoot pain. Radiographs are unremarkable, but a subsequent MRI reveals a stress fracture through the central third of the tarsal navicular.

Why is this specific anatomical location at a high risk for delayed union or nonunion?

. It is the primary attachment site of the tibialis posterior tendon
. It represents an avascular watershed zone in the intraosseous blood supply
. It undergoes constant distraction forces during the toe-off phase of gait
. It articulates with the three cuneiforms, increasing shear stress
. It is covered entirely by articular cartilage, preventing periosteal callus formation

Correct Answer & Explanation

. It represents an avascular watershed zone in the intraosseous blood supply

Explanation

The tarsal navicular receives its blood supply from branches of the dorsalis pedis and medial plantar arteries. These vessels enter the bone dorsally and plantarly, respectively. The central third of the navicular body represents an area of relative avascularity (a watershed zone) between these two blood supplies. Stress fractures in this region have a high risk of delayed union or nonunion and often require prolonged non-weight-bearing cast immobilization or surgical intervention.

Question 4458

Topic: 2. Trauma

In the management of severe (AO/OTA 43-C3) pilon fractures, the evolution from immediate internal fixation to a staged protocol (initial external fixation followed by delayed ORIF) was primarily driven by the unacceptably high rate of which specific complication?

. Nonunion of the tibial metaphysis
. Post-traumatic osteoarthritis of the tibiotalar joint
. Severe soft tissue complications including wound necrosis and deep infection
. Iatrogenic neurovascular injury during definitive fixation
. Malunion with profound varus deformity

Correct Answer & Explanation

. Nonunion of the tibial metaphysis

Explanation

Historically, immediate open reduction and internal fixation of high-energy pilon fractures through swollen, traumatized soft tissue envelopes resulted in catastrophic wound complications, including skin necrosis, wound dehiscence, osteomyelitis, and eventual amputations. Sirkin et al. and Patterson and Krause popularized the staged protocol (spanning ex-fix, delay for soft tissue recovery, then definitive ORIF), which dramatically reduced the incidence of these severe soft tissue complications and deep infections.

Question 4459

Topic: 2. Trauma

A 38-year-old male presents with a comminuted distal tibia pilon fracture. The surgeon plans an anterolateral approach to the distal tibia. During this approach, which of the following nerves is at greatest risk of iatrogenic injury as it crosses the surgical field?

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

Correct Answer & Explanation

. Deep peroneal nerve

Explanation

The superficial peroneal nerve is at greatest risk during the anterolateral approach to the distal tibia, as its branches cross the surgical field from medial to lateral over the extensor retinaculum. The deep peroneal nerve is located more medially alongside the anterior tibial artery and is protected when dissecting in the correct interval (between the peroneus tertius and extensor digitorum longus, or lateral to the EDL).

Question 4460

Topic: 2. Trauma

In the Sanders classification system for intra-articular calcaneus fractures, which specific imaging modality and view is primarily utilized to determine the classification?

. Harris axial radiograph
. Broden's view radiograph
. Lateral radiograph
. Coronal CT scan through the widest portion of the posterior facet
. Axial CT scan parallel to the plantar fascia

Correct Answer & Explanation

. Harris axial radiograph

Explanation

The Sanders classification relies on coronal CT scan images. Specifically, it evaluates the fracture lines through the widest portion of the posterior articular facet of the calcaneus. It divides the facet into three columns using two fracture lines (A and B) and a third line (C) separating the posterior facet from the sustentaculum tali. The classification (I-IV) depends on the number and location of articular fracture lines.

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