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2. Trauma MCQs

Practice Set 532 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 10621

Topic: 2. Trauma

The Reamer-Irrigator-Aspirator (RIA) system is frequently used to harvest large volumes of autologous bone graft from the femoral intramedullary canal. Which of the following is the most common serious complication specific to this technique?

. High-pressure fat embolism
. Iatrogenic cortical perforation or fracture
. Deep vein thrombosis
. Osteomyelitis of the donor femur
. Complete avascular necrosis of the femoral head

Correct Answer & Explanation

. High-pressure fat embolism

Explanation

While the RIA system provides excellent autogenous graft volume and lowers intramedullary pressure during use compared to standard reaming, its most common serious complication is eccentric reaming. This can lead to severe iatrogenic cortical thinning, perforation, or frank postoperative fracture of the donor femur. Careful fluoroscopic monitoring is mandatory.

Question 10622

Topic: 2. Trauma
A 35-year-old polytrauma patient arrives in hemorrhagic shock with an open pelvic book fracture. The massive transfusion protocol (MTP) is activated. Current trauma resuscitation guidelines recommend administering PRBCs, FFP, and platelets in what ratio to best mimic whole blood?
. 1:1:1
. 3:1:1
. 4:2:1
. 2:1:1
. 1:2:2

Correct Answer & Explanation

. 1:1:1

Explanation

Based on landmark studies like the PROPPR trial, the standard of care for damage control resuscitation in severely bleeding trauma patients is a balanced ratio of 1:1:1 (PRBCs : FFP : Platelets). This proactively addresses trauma-induced coagulopathy by replacing clotting factors and platelets concurrently with oxygen-carrying red blood cells.

Question 10623

Topic: 2. Trauma

A 28-year-old male sustains a transverse subtrochanteric femur fracture. Due to the specific muscular attachments, what is the classic predictable deformity of the proximal fracture fragment?

. Extension, adduction, and internal rotation
. Flexion, adduction, and internal rotation
. Flexion, abduction, and external rotation
. Extension, abduction, and internal rotation
. Flexion, adduction, and external rotation

Correct Answer & Explanation

. Extension, adduction, and internal rotation

Explanation

The proximal fragment in a subtrochanteric fracture is deformed by powerful muscle forces: the iliopsoas (lesser trochanter) causes flexion and external rotation, while the gluteus medius and minimus (greater trochanter) cause abduction. The short external rotators further contribute to external rotation. Therefore, the classic deformity is flexion, abduction, and external rotation.

Question 10624

Topic: 2. Trauma

A patient sustains an open pelvic ring injury in a high-speed collision. In the acute setting (within the first 24 hours), what is the most common cause of mortality in patients with this severe injury pattern?

. Severe sepsis
. Acute respiratory distress syndrome (ARDS)
. Exsanguinating hemorrhage
. Pulmonary embolism
. Fat embolism syndrome

Correct Answer & Explanation

. Severe sepsis

Explanation

Open pelvic fractures are devastating injuries. In the acute phase (< 24 hours), the most common cause of mortality is exsanguinating hemorrhage arising from the highly vascular presacral venous plexus, major iliac vessels, and cancellous bone surfaces. If the patient survives the initial hemorrhagic shock, late mortality is most frequently due to sepsis and multi-organ failure.

Question 10625

Topic: 2. Trauma

The concept of 'Early Appropriate Care' (EAC) advocates for definitive fixation of major long bone fractures early in polytrauma patients if specific physiologic parameters are met. Which of the following laboratory values indicates a patient is sufficiently resuscitated to proceed with EAC?

. pH > 7.15
. Lactate < 4.0 mmol/L
. Base excess < -8.0 mmol/L
. Hemoglobin > 8.0 g/dL
. Fibrinogen > 100 mg/dL

Correct Answer & Explanation

. pH > 7.15

Explanation

Early Appropriate Care (EAC) guidelines indicate that it is safe to proceed with definitive fracture fixation (e.g., within 36 hours) if the patient's physiology is optimized. Validated laboratory thresholds include a serum lactate < 4.0 mmol/L, pH >= 7.25, and base excess >= -5.5 mmol/L. These values confirm adequate restoration of tissue perfusion, reducing the risk of fatal systemic inflammatory responses to the surgery.

Question 10626

Topic: Pelvic & Acetabular Trauma

Emergency medical services bring in a hypotensive patient with a suspected 'open book' pelvic fracture. A pelvic binder was applied in the field. To effectively reduce pelvic volume and mechanically control hemorrhage, the binder should be centered precisely over which anatomical landmark?

. The iliac crests
. The anterior superior iliac spines (ASIS)
. The umbilicus
. The greater trochanters
. The pubic symphysis

Correct Answer & Explanation

. The iliac crests

Explanation

To optimally close an open-book pelvic ring injury and reduce intrapelvic volume (thereby creating a tamponade effect), the compressive force must be applied directly across the greater trochanters. Placing the binder too high (over the iliac crests or ASIS) compresses the false pelvis, failing to stabilize the true pelvic ring and potentially paradoxically opening the symphysis further.

Question 10627

Topic: 2. Trauma

An 80-year-old male is admitted after a ground-level fall, resulting in three unilateral rib fractures. He is neurologically intact and stable. Which of the following complications is he at the highest risk of developing, representing a major predictor of mortality in geriatric trauma?

. Aortic dissection
. Flail chest
. Pneumonia
. Tension pneumothorax
. Myocardial contusion

Correct Answer & Explanation

. Aortic dissection

Explanation

Rib fractures in the elderly are highly morbid due to decreased physiologic reserve. Pain leads to splinting, hypoventilation, and an inability to clear secretions, making the development of pneumonia the most significant risk and a major cause of mortality. Aggressive multimodal pain control (often epidural) and pulmonary hygiene are essential.

Question 10628

Topic: 2. Trauma
Which of the following is considered an absolute indication for operative fixation of a scapula fracture?
. Glenopolar angle of 35 degrees
. Medialization of the lateral border of 10 mm
. Intra-articular step-off greater than 4 mm at the anterior glenoid rim
. Scapular body fracture with 10 mm displacement
. Angulation of the scapular body of 20 degrees

Correct Answer & Explanation

. Intra-articular step-off greater than 4 mm at the anterior glenoid rim

Explanation

Indications for operative fixation of a scapula fracture include intra-articular glenoid displacement > 4 mm, glenopolar angle < 22 degrees, medialization of the lateral border > 20 mm, and severe double disruptions of the superior suspensory shoulder complex (SSSC). A glenopolar angle of 35 degrees is within normal limits (30-45 degrees).

Question 10629

Topic: 2. Trauma

A 25-year-old male develops acute compartment syndrome of the leg following a tibial shaft fracture. The surgeon elects to perform a dual-incision fasciotomy. During the medial approach, which specific surgical step is critical to adequately release the deep posterior compartment?

. Incising the fascia over the superficial posterior compartment only
. Detaching the soleus origin from the posteromedial border of the tibia
. Releasing the intermuscular septum between the anterior and lateral compartments
. Transecting the interosseous membrane from anterior to posterior
. Decompressing the tarsal tunnel at the ankle

Correct Answer & Explanation

. Incising the fascia over the superficial posterior compartment only

Explanation

During the medial approach of a two-incision fasciotomy for the leg, the superficial posterior compartment is released first. The deep posterior compartment is then accessed by retracting the superficial compartment posteriorly and detaching the soleus fascial bridge from the posteromedial border of the tibia. Failure to release this fascial attachment is the most common reason for an incomplete decompression of the deep posterior compartment.

Question 10630

Topic: Lower Extremity Trauma

A 45-year-old male presents with a Schatzker Type IV tibial plateau fracture with a large posteromedial shear fragment. The surgeon plans a posteromedial approach with the patient in the prone position. The optimal internervous/intermuscular interval for this approach is between the:

. Medial head of the gastrocnemius and the soleus
. Medial head of the gastrocnemius and the pes anserinus
. Lateral head of the gastrocnemius and the biceps femoris
. Tibialis posterior and the flexor hallucis longus
. Semimembranosus and the semitendinosus

Correct Answer & Explanation

. Medial head of the gastrocnemius and the soleus

Explanation

The posteromedial approach to the tibial plateau utilizes the interval between the medial head of the gastrocnemius (which is retracted laterally, protecting the neurovascular bundle) and the pes anserinus/semimembranosus tendons (which are retracted medially). This provides excellent visualization for buttress plating of posteromedial shear fragments.

Question 10631

Topic: 2. Trauma

A 35-year-old male sustains a high-energy OTA 43-C3 distal tibia pilon fracture. On presentation, the skin is tense with hemorrhagic fracture blisters. He is initially managed with a joint-spanning external fixator. What is the most reliable clinical indicator that the soft tissues are ready for definitive open reduction and internal fixation?

. Resolution of hemorrhagic blisters with epithelialization and presence of the 'wrinkle sign'
. Normalization of the erythrocyte sedimentation rate (ESR)
. 72 hours post-injury regardless of swelling
. Pin site drainage from the external fixator
. Appearance of bridging callus on radiographs

Correct Answer & Explanation

. Resolution of hemorrhagic blisters with epithelialization and presence of the 'wrinkle sign'

Explanation

Pilon fractures are frequently associated with severe soft tissue compromise. Standard protocol involves a staged approach: immediate spanning external fixation followed by definitive ORIF once the soft tissues have recovered. The 'wrinkle sign'โ€”the return of normal skin wrinkling with resolution of tense edema and re-epithelialization of blistersโ€”is the most reliable clinical sign that the soft tissue envelope can safely tolerate surgical incisions, typically occurring 10-14 days post-injury.

Question 10632

Topic: Pelvic & Acetabular Trauma
A 28-year-old male involved in a high-speed motor vehicle collision sustains an anteroposterior compression type III (APC-III) pelvic ring injury. After successful hemodynamic resuscitation and application of a pelvic binder, what is the most appropriate definitive orthopedic management?
. Anterior symphyseal plating alone
. Percutaneous posterior sacroiliac screw fixation alone
. Both anterior symphyseal fixation and posterior pelvic ring stabilization
. Application of an anterior supra-acetabular external fixator alone
. Non-operative management with skeletal traction

Correct Answer & Explanation

. Both anterior symphyseal fixation and posterior pelvic ring stabilization

Explanation

An APC-III pelvic ring injury is rotationally and vertically unstable, characterized by complete disruption of the pubic symphysis (or rami) anteriorly, and complete disruption of the anterior and posterior sacroiliac ligaments posteriorly. Definitive management necessitates stabilization of both the anterior and posterior ring to restore stability and pelvic volume.

Question 10633

Topic: Pelvic & Acetabular Trauma

On the standard AP pelvis radiograph of a 40-year-old male trauma patient, the iliopectineal line is disrupted, but the ilioischial line and the posterior wall margin remain intact. According to the Letournel and Judet classification, which structural component of the acetabulum is fractured?

. Anterior column
. Posterior column
. Transverse
. T-shaped
. Posterior wall

Correct Answer & Explanation

. Anterior column

Explanation

The radiographic lines of the acetabulum on an AP pelvis view correlate with specific anatomical structures. The iliopectineal line represents the anterior column, and the ilioischial line represents the posterior column. Disruption of the iliopectineal line with an intact ilioischial line indicates an isolated anterior column fracture.

Question 10634

Topic: 2. Trauma

A 24-year-old male sustains a distal femur fracture after a motorcycle accident. A computed tomography (CT) scan is obtained to characterize the articular involvement, revealing a coronal plane fracture of the lateral femoral condyle. What is the eponymous name of this fracture?

. Barton fracture
. Chauffeur's fracture
. Hoffa fracture
. Tillaux fracture
. Chaput fracture

Correct Answer & Explanation

. Barton fracture

Explanation

A Hoffa fracture is a coronal plane fracture of the femoral condyle (most commonly the lateral condyle). Because it is an intra-articular shear fracture, it requires rigid anatomic fixation, typically with anterior-to-posterior (AP) or posterior-to-anterior (PA) lag screws, often supplemented with a neutralization plate.

Question 10635

Topic: 2. Trauma

A 30-year-old male sustains a subtrochanteric fracture of the femur. Which combination of muscles is primarily responsible for the typical flexion, abduction, and external rotation deformity of the proximal fracture fragment?

. Flexion by iliopsoas, abduction by gluteus medius/minimus, external rotation by short external rotators
. Flexion by rectus femoris, abduction by tensor fasciae latae, external rotation by gluteus maximus
. Extension by hamstrings, adduction by adductor longus, internal rotation by gluteus minimus
. Flexion by sartorius, abduction by gluteus maximus, external rotation by piriformis
. Flexion by pectineus, adduction by adductor magnus, internal rotation by obturator internus

Correct Answer & Explanation

. Flexion by iliopsoas, abduction by gluteus medius/minimus, external rotation by short external rotators

Explanation

In subtrochanteric fractures, the proximal fragment is acted upon by robust muscular forces causing a predictable deformity: the iliopsoas flexes the fragment, the gluteus medius and minimus abduct it, and the short external rotators externally rotate it. The distal fragment is pulled proximally and adducted by the hamstrings and adductor musculature.

Question 10636

Topic: 2. Trauma

A 75-year-old female undergoes cephalomedullary nailing for a reverse obliquity intertrochanteric femur fracture. To minimize the risk of lag screw cut-out from the femoral head, the surgeon utilizes the Tip-Apex Distance (TAD) concept described by Baumgaertner. What is the maximum recommended TAD to effectively reduce the risk of cut-out?

. 10 mm
. 15 mm
. 20 mm
. 25 mm
. 35 mm

Correct Answer & Explanation

. 10 mm

Explanation

The Tip-Apex Distance (TAD) is the sum of the distance from the tip of the lag screw to the apex of the femoral head on the AP and lateral radiographs. Baumgaertner demonstrated that a TAD of less than 25 mm is highly predictive of successful fixation, whereas a TAD > 25 mm significantly increases the risk of lag screw cut-out.

Question 10637

Topic: 2. Trauma
A 25-year-old male sustains a Pauwels Type III (high vertical shear angle) femoral neck fracture. Biomechanical studies have demonstrated that using a sliding hip screw with a derotation screw, compared to three parallel cannulated cancellous screws, provides which of the following advantages for this specific fracture pattern?
. Elimination of the risk of avascular necrosis
. Superior construct stiffness and resistance to vertical shear forces
. Increased fracture gap to promote secondary bone healing
. Decreased operative time and blood loss
. Preservation of the lateral epiphyseal vessels

Correct Answer & Explanation

. Superior construct stiffness and resistance to vertical shear forces

Explanation

Pauwels Type III femoral neck fractures have a fracture line greater than 50 degrees relative to horizontal, creating massive vertical shear forces. Biomechanical studies show that a fixed-angle device such as a sliding hip screw (often supplemented with a derotation screw) provides superior construct stiffness and resists vertical shear and varus collapse much better than three parallel cannulated screws.

Question 10638

Topic: 2. Trauma

A 40-year-old male presents to the emergency department after a fall onto an outstretched hand, sustaining a 'terrible triad' injury of the elbow. Which of the following is NOT a classic component of this injury pattern?

. Elbow dislocation
. Radial head fracture
. Coronoid process fracture
. Disruption of the lateral collateral ligament (LCL) complex
. Olecranon fracture

Correct Answer & Explanation

. Elbow dislocation

Explanation

The 'terrible triad' of the elbow historically refers to an elbow dislocation associated with a radial head fracture and a coronoid fracture. The dislocation universally causes disruption of the lateral collateral ligament (LCL) complex (and often the MCL). An olecranon fracture is not a component of the terrible triad; injuries with olecranon fractures, coronoid fractures, and radial head fractures are typically transolecranon fracture-dislocations.

Question 10639

Topic: 2. Trauma

A 65-year-old female sustains a displaced 4-part proximal humerus fracture. According to Hertel's radiographic criteria, which of the following is the strongest predictor of subsequent avascular necrosis (ischemia) of the humeral head?

. Displacement of the greater tuberosity greater than 5 mm
. Posteromedial metaphyseal hinge length (calcar extension) less than 2 mm
. Varus angulation of the humeral head greater than 20 degrees
. Inferior subluxation of the humeral head
. Valgus impaction of the humeral head

Correct Answer & Explanation

. Displacement of the greater tuberosity greater than 5 mm

Explanation

Hertel identified specific radiographic predictors for ischemia (AVN risk) of the humeral head following proximal humerus fractures. The most reliable predictors are a posteromedial metaphyseal hinge length (calcar extension) of less than 2 mm, an absent medial hinge (medial displacement of the shaft > 2mm), and an anatomical neck (basicervical) fracture pattern.

Question 10640

Topic: Lower Extremity Trauma

A 22-year-old collegiate football player sustains a midfoot injury during a tackle. Weight-bearing radiographs demonstrate 3 mm of widening between the base of the first and second metatarsals, with a 'fleck sign' visible in the intercuneiform space. What is the most appropriate management for this athlete?

. Non-weight-bearing in a short leg cast for 6 weeks
. Immediate return to play with a rigid carbon-fiber orthotic
. Open reduction and internal fixation or primary arthrodesis of the Lisfranc complex
. Corticosteroid injection into the tarsometatarsal joints
. Closed reduction and percutaneous pinning with smooth Kirschner wires

Correct Answer & Explanation

. Non-weight-bearing in a short leg cast for 6 weeks

Explanation

The presentation describes a ligamentous Lisfranc injury with instability (diastasis > 2 mm and a positive 'fleck sign' representing avulsion of the Lisfranc ligament). Non-operative management is inadequate for unstable injuries. Stable anatomic fixation via Open Reduction Internal Fixation (ORIF) or primary arthrodesis is required to prevent debilitating post-traumatic midfoot arthrosis.

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