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2. Trauma MCQs

Practice Set 477 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 9521

Topic: 2. Trauma

A 60-year-old male with a history of metastatic renal cell carcinoma to the proximal femur presents with sudden onset of severe right thigh pain after a minor fall. Radiographs show a pathological subtrochanteric fracture. He has a 3-month life expectancy. What is the most appropriate surgical management principle for this patient?

. Extensive wide en bloc resection and reconstruction
. Percutaneous cement augmentation (vertebroplasty/kyphoplasty-like for long bone)
. Intramedullary nailing for stabilization
. External fixation
. Radiation therapy alone

Correct Answer & Explanation

. Intramedullary nailing for stabilization

Explanation

For pathological fractures of long bones due to metastatic disease, especially in patients with a limited life expectancy, the primary goals of surgical management are pain relief, early mobilization, and improved quality of life. Intramedullary nailing is an excellent choice for subtrochanteric and diaphyseal fractures as it provides stable fixation, allows immediate weight-bearing, and is a less extensive procedure compared to wide en bloc resection. Wide en bloc resection is usually reserved for primary bone tumors or highly selected metastases with long life expectancy. Percutaneous cement augmentation is not suitable for displaced long bone fractures. External fixation is generally a temporary measure. Radiation therapy is often an adjunct to surgery but insufficient as a standalone treatment for a displaced, unstable fracture.

Question 9522

Topic: 2. Trauma
A 40-year-old male sustains a severe open tibia fracture with a >10 cm laceration, extensive soft tissue damage, periosteal stripping, and significant contamination from a farm accident. The fracture is comminuted. There is no major neurovascular compromise. According to the Gustilo-Anderson classification, what is the most likely classification and initial management priority?
. Type I, irrigation and debridement within 24 hours
. Type II, irrigation and debridement within 12 hours
. Type IIIA, irrigation and debridement, followed by internal fixation
. Type IIIB, irrigation and debridement, with plans for soft tissue coverage
. Type IIIC, immediate amputation

Correct Answer & Explanation

. Type IIIB, irrigation and debridement, with plans for soft tissue coverage

Explanation

The Gustilo-Anderson classification for open fractures: Type I (<1 cm wound, clean), Type II (1-10 cm wound, moderate soft tissue damage), Type III (>10 cm wound, extensive soft tissue damage). Type III is further subdivided: IIIA involves extensive soft tissue damage with adequate soft tissue coverage. Type IIIB involves extensive soft tissue loss, periosteal stripping, significant contamination, and exposed bone requiring flap coverage. Type IIIC includes an associated arterial injury requiring repair. This patient's description of a >10 cm laceration, extensive soft tissue damage, periosteal stripping, and significant contamination directly fits Type IIIB. The management priority for Type IIIB is aggressive irrigation and debridement, followed by plans for definitive soft tissue coverage (e.g., local or free flap) to prevent infection and promote healing.

Question 9523

Topic: 2. Trauma

A 22-year-old long-distance runner complains of bilateral lower leg pain, tightness, and weakness that consistently develops 10-15 minutes into his runs and resolves with rest. Physical examination is unremarkable at rest, but palpable tenderness and firmness are noted in the anterior compartments bilaterally after exertion. There are no acute signs of compartment syndrome. What is the most definitive diagnostic test for chronic exertional compartment syndrome (CECS)?

. MRI of the lower leg
. CT scan of the lower leg
. Resting compartment pressures
. Post-exercise compartment pressures
. Electromyography (EMG)

Correct Answer & Explanation

. Post-exercise compartment pressures

Explanation

Chronic exertional compartment syndrome (CECS) is a clinical diagnosis confirmed by objective measurement of intramuscular compartment pressures. The most definitive diagnostic test involves measuring compartment pressures before, during, and typically 1 and 5 minutes after a standardized exercise that reproduces the patient's symptoms. Elevated pressures post-exercise, combined with characteristic symptoms that resolve with rest, are diagnostic. MRI may show muscle edema but is not definitive. CT scan is not useful. Resting compartment pressures are typically normal in CECS. EMG is used for nerve conduction studies to rule out nerve entrapment but is not diagnostic for CECS.

Question 9524

Topic: 2. Trauma
A 48-year-old male presents after a high-energy motor vehicle collision with an associated posterior hip dislocation and a transverse acetabular fracture (Letournel & Judet classification). Post-reduction CT reveals a large posterior wall fragment, an incarcerated fragment within the joint, and significant articular step-off. Neurological examination is intact. What is the most appropriate definitive management strategy?
. Percutaneous screw fixation of the acetabular fracture immediately.
. Closed reduction with traction followed by conservative management.
. Open reduction and internal fixation (ORIF) of the acetabular fracture via a Kocher-Langenbeck approach with extraction of the incarcerated fragment.
. Open reduction and internal fixation (ORIF) of the acetabular fracture via an ilioinguinal approach.
. Limited arthroscopic debridement of the incarcerated fragment and continued traction.

Correct Answer & Explanation

. Open reduction and internal fixation (ORIF) of the acetabular fracture via a Kocher-Langenbeck approach with extraction of the incarcerated fragment.

Explanation

This patient presents with an unstable acetabular fracture (transverse with a large posterior wall fragment) and an incarcerated fragment after posterior hip dislocation. The incarcerated fragment necessitates surgical removal to prevent post-traumatic arthritis. A transverse fracture, especially with posterior wall involvement, often requires ORIF. The Kocher-Langenbeck approach is ideal for posterior wall and posterior column fractures, allowing excellent visualization for fragment extraction and stable fixation. Percutaneous fixation is not suitable for incarcerated fragments or significant step-off. Conservative management is inappropriate for unstable, displaced fractures with incarcerated fragments. An ilioinguinal approach is primarily for anterior column/wall fractures. Arthroscopic debridement alone would not address the fracture displacement and instability.

Question 9525

Topic: 2. Trauma

A 35-year-old male sustains a high-energy pilon fracture (OTA/AO 43-C3) with extensive comminution, significant soft tissue swelling, and tense blisters over the ankle. Initial management includes a temporary spanning external fixator. What is the most appropriate timing for definitive open reduction and internal fixation (ORIF)?

. Immediately, within 6-8 hours of injury to prevent stiffening.
. Within 24-48 hours, after initial swelling reduction.
. After the soft tissue envelope has recovered, typically 7-14 days post-injury, when skin wrinkles are present.
. Only after the external fixator has been removed and partial weight-bearing has started.
. Never, as external fixation is usually the definitive treatment for severe pilon fractures.

Correct Answer & Explanation

. After the soft tissue envelope has recovered, typically 7-14 days post-injury, when skin wrinkles are present.

Explanation

For high-energy pilon fractures with significant soft tissue compromise (swelling, blistering), a staged approach is crucial to minimize wound complications. Initial management involves temporizing with a spanning external fixator to restore length, alignment, and indirectly reduce some fragments, allowing the soft tissue envelope to recover. Definitive ORIF should be delayed until the soft tissues are amenable to surgery, which is typically 7-14 days post-injury when the 'wrinkle sign' is present (meaning the skin can be easily wrinkled). Operating immediately on compromised soft tissues significantly increases the risk of wound breakdown, infection, and poor outcomes. External fixation alone is usually not definitive for articular fractures requiring precise reduction, unless the patient is too medically unstable for ORIF.

Question 9526

Topic: 2. Trauma

A 28-year-old male sustains a severe crush injury to his forearm during an industrial accident, resulting in comminuted radius and ulna shaft fractures. Six hours post-injury, he reports excruciating, constant forearm pain unresponsive to analgesics. On examination, his forearm is tense and swollen, he has severe pain with passive extension of his fingers, and decreased sensation in the median nerve distribution. Distal radial and ulnar pulses are palpable. What is the most crucial surgical step?

. Emergent open reduction and internal fixation of the radius and ulna fractures.
. Immediate forearm fasciotomy.
. Nerve decompression of the median and ulnar nerves.
. Observation with serial neurological and vascular examinations every hour.
. Application of a bivalved cast and elevation.

Correct Answer & Explanation

. Immediate forearm fasciotomy.

Explanation

This patient presents with classic signs and symptoms of acute forearm compartment syndrome: excruciating pain out of proportion to injury, pain with passive stretch of fingers, tense compartments, and early sensory deficits (median nerve). While pulses may still be palpable initially, compartment pressures are likely elevated to critical levels. The most crucial and time-sensitive surgical step is an immediate forearm fasciotomy to decompress all involved compartments (superficial volar, deep volar, dorsal, mobile wad). Delay in fasciotomy can lead to irreversible muscle necrosis, nerve damage, and Volkmann's ischemic contracture. Open reduction and internal fixation of the fractures may follow fasciotomy, but decompression is primary. Nerve decompression alone is insufficient. Observation or cast application is contraindicated as it will worsen the ischemia.

Question 9527

Topic: 2. Trauma
A 55-year-old male presents with persistent low back pain radiating to his left buttock and perineum following a motor vehicle accident. He denies bowel or bladder dysfunction but reports difficulty with left foot plantarflexion and decreased sensation over the posterior aspect of his left leg and sole of his foot. An MRI reveals a comminuted L5 sacral fracture extending into the S1 foramen (Denis Zone III). Which of the following is the most critical initial management step specific to this fracture type?
. Immediate operative fixation of the sacral fracture.
. Conservative management with bed rest and pain control.
. Assessment for spinopelvic dissociation and associated injuries.
. Thorough neurological examination, specifically evaluating S2-S4 nerve root function.
. Application of a thoracolumbosacral orthosis (TLSO).

Correct Answer & Explanation

. Thorough neurological examination, specifically evaluating S2-S4 nerve root function.

Explanation

Denis Zone III sacral fractures involve the lateral sacral mass and are associated with a high risk of lumbosacral plexopathy and nerve root injury, particularly the S2-S4 nerve roots which control bowel, bladder, and sexual function. While spinopelvic dissociation and operative fixation are important considerations, the immediate and most critical step for this specific fracture type with neurological symptoms is a thorough neurological examination to precisely document the deficits, especially S2-S4 function, which guides subsequent management decisions and allows for prognosis. Early detection of cauda equina syndrome, although not explicitly stated here, would be an emergency requiring immediate decompression. Assessment for spinopelvic dissociation is crucial for stability but a detailed neurological exam takes precedence for acute management of neurological compromise.

Question 9528

Topic: 2. Trauma

A 40-year-old construction worker falls from a height, sustaining a high-energy comminuted intra-articular fracture of the distal tibia (Pilon fracture, AO/OTA 43-C3) with significant swelling and multiple skin blisters visible. There are no signs of open fracture or neurovascular compromise. What is the most appropriate initial management strategy?

. Emergent open reduction and internal fixation (ORIF) to restore joint congruity.
. Application of a short leg cast and immediate weight-bearing.
. Immediate traction with calcaneal pin insertion.
. External fixation spanning the ankle joint with delayed definitive ORIF after soft tissue improvement.
. Administration of systemic antibiotics and observation for 24 hours.

Correct Answer & Explanation

. External fixation spanning the ankle joint with delayed definitive ORIF after soft tissue improvement.

Explanation

High-energy Pilon fractures often present with severe soft tissue injury, including significant swelling and blistering. Immediate definitive ORIF in such circumstances carries a very high risk of wound complications, infection, and flap necrosis. The standard of care for these injuries is a staged approach. Initial management involves temporizing external fixation to stabilize the fracture, restore length, and allow the soft tissues to recover (swelling reduction, blister resolution). Definitive ORIF is then performed electively, typically 7-14 days later, when the 'wrinkle sign' is present, indicating adequate soft tissue readiness. Immediate traction might reduce some swelling but is less effective for stabilization than external fixation.

Question 9529

Topic: 2. Trauma

A 25-year-old male sustains a severe crush injury to his right forearm, resulting in significantly elevated compartment pressures confirmed by direct measurement (55 mmHg in the superficial volar compartment). He complains of severe, unremitting pain, paresthesias in his fingers, and pain on passive extension of his digits. What is the definitive immediate management for this condition?

. Elevation of the limb and application of ice.
. Administration of strong opioid analgesics.
. Emergency fasciotomy of the affected compartments.
. Observation for signs of arterial compromise and repeat compartment pressure measurements in 6 hours.
. Application of a tight compression dressing to reduce swelling.

Correct Answer & Explanation

. Emergency fasciotomy of the affected compartments.

Explanation

The patient's symptoms (severe pain, paresthesias, pain on passive stretch, elevated compartment pressures) are classic for acute compartment syndrome. This is a surgical emergency. The definitive immediate management is an emergency fasciotomy of all affected compartments to relieve pressure and prevent irreversible muscle and nerve damage. Delay in treatment can lead to Volkmann's ischemic contracture, nerve palsy, or limb loss. Elevation, ice, and compression dressings are contraindicated as they can exacerbate ischemia. Analgesics address symptoms but not the underlying pathophysiology. Observation would be negligent given the confirmed high pressures and clinical signs.

Question 9530

Topic: 2. Trauma

A 24-year-old soccer player sustains a twisting injury to his knee. Radiographs reveal a small cortical avulsion fracture off the lateral tibial plateau, just distal to the joint line. Which ligamentous structure has its distal insertion at this fracture site?

. Fibular collateral ligament
. Popliteofibular ligament
. Anterolateral ligament
. Posterior oblique ligament
. Arcuate ligament

Correct Answer & Explanation

. Anterolateral ligament

Explanation

The radiograph describes a Segond fracture, an avulsion fracture of the anterolateral proximal tibia that is pathognomonic for an anterior cruciate ligament (ACL) tear. The Segond fragment represents the tibial bony insertion of the anterolateral ligament (ALL) and the anterolateral joint capsule.

Question 9531

Topic: 2. Trauma

A 9-year-old boy falls from a height and sustains a transepiphyseal fracture of the proximal femur (Delbet Type I) with dislocation of the femoral head. Following prompt open reduction and internal fixation, what is the most likely and devastating complication to occur?

. Nonunion
. Avascular necrosis (AVN) of the femoral head
. Coxa vara
. Chondrolysis
. Femoral nerve palsy

Correct Answer & Explanation

. Avascular necrosis (AVN) of the femoral head

Explanation

Pediatric femoral neck fractures are classified by the Delbet classification. Delbet Type I (transepiphyseal fracture/separation) is the rarest but carries the highest risk of avascular necrosis (AVN) of the femoral head, approaching 80-100% when displaced or accompanied by dislocation, due to the complete disruption of the epiphyseal blood supply.

Question 9532

Topic: 2. Trauma

A 42-year-old male suffers a high-energy varus-directed force to his knee during a motor vehicle collision. Radiographs reveal a displaced fracture of the medial tibial plateau with depression and separation of the medial fragment. Which of the following vascular structures is at the highest risk of injury in this specific fracture pattern?

. Anterior tibial artery at the level of the interosseous membrane
. Posterior tibial artery in the distal third of the leg
. Popliteal artery at the level of the popliteal trifurcation
. Peroneal artery traversing the lateral compartment
. Medial inferior genicular artery

Correct Answer & Explanation

. Popliteal artery at the level of the popliteal trifurcation

Explanation

This is a Schatzker Type IV medial tibial plateau fracture. Occurring via a high-energy varus stress, medial plateau fractures are notorious for severe associated soft tissue injuries, including peroneal nerve palsies and lateral collateral ligament disruption. Critically, there is a high risk of damage to the popliteal artery/trifurcation due to posterior subluxation of the knee or the displacement of the medial plateau fragment.

Question 9533

Topic: 2. Trauma

A patient presents with a multi-apical varus deformity of the femur following a malunited segmental fracture. How should the CORAs be determined during preoperative planning?

. By drawing a single mechanical axis line from the hip to the knee
. By the intersection of the proximal, middle, and distal anatomical axis lines
. By measuring the mechanical axis deviation at the joint line
. By finding the intersection of the proximal and distal joint orientation lines only
. By templating the contralateral normal limb and superimposing it

Correct Answer & Explanation

. By the intersection of the proximal, middle, and distal anatomical axis lines

Explanation

For multi-apical deformities, the anatomical axis of the middle segment must be drawn. Its intersections with the proximal and distal anatomical axes define the two distinct CORAs that require independent correction.

Question 9534

Topic: Lower Extremity Trauma

When measuring the normal proximal femoral geometry on an AP radiograph, what is the accepted normal range for the Lateral Proximal Femoral Angle (LPFA) and Mechanical Lateral Proximal Femoral Angle (mLPFA)?

. LPFA 80 degrees, mLPFA 80 degrees
. LPFA 90 degrees, mLPFA 90 degrees
. LPFA 100 degrees, mLPFA 90 degrees
. LPFA 130 degrees, mLPFA 130 degrees
. LPFA 85 degrees, mLPFA 95 degrees

Correct Answer & Explanation

. LPFA 90 degrees, mLPFA 90 degrees

Explanation

The normal LPFA (anatomical) and mLPFA (mechanical) are both approximately 90 degrees. This reflects the relationship between the tip of the greater trochanter and the center of the femoral head relative to the femoral shaft.

Question 9535

Topic: 2. Trauma

An osteotomy of the distal tibia is planned for malunion. The Center of Rotation of Angulation (CORA) is identified 1 cm proximal to the joint line. To avoid capsular penetration, the osteotomy is performed 4 cm proximal to the joint, but the Axis of Correction of Angulation (ACA) is placed exactly at the CORA. According to Paley's Rule 2, what is the geometric result?

. Pure angulation with parallel axis displacement
. Angulation and translation at the osteotomy site with colinear mechanical axes
. Pure translation at the osteotomy site
. Opening wedge angulation without translation
. Angulation with worsening of mechanical axis deviation

Correct Answer & Explanation

. Angulation and translation at the osteotomy site with colinear mechanical axes

Explanation

Paley's Rule 2 states that if the ACA is at the CORA but the osteotomy is at a different level, the correction will result in angulation and translation at the osteotomy site. However, the proximal and distal mechanical axes will be realigned colinearly.

Question 9536

Topic: Lower Extremity Trauma

During an Ilizarov pelvic support osteotomy for a chronically dislocated hip, the proximal femoral osteotomy is placed in extension and valgus. What clinical parameter dictates the optimal amount of valgus angulation required at the proximal osteotomy?

. The angle required to make the femoral shaft purely vertical.
. The degree of preoperative Trendelenburg dip.
. The maximum adduction of the femur to the pelvis plus 15 degrees for overcorrection.
. The contralateral anatomic neck-shaft angle.
. A fixed correction of exactly 45 degrees for all patients.

Correct Answer & Explanation

. The maximum adduction of the femur to the pelvis plus 15 degrees for overcorrection.

Explanation

The valgus angle is determined by maximal adduction of the hip with the pelvis level. Paley recommends overcorrecting this angle by 10 to 15 degrees to guarantee elimination of the Trendelenburg drop and provide a strong pelvic support strut.

Question 9537

Topic: 2. Trauma

A patient is evaluated for a rigid equinus contracture due to a distal tibia fracture malunion. Radiographs reveal a distinct apex anterior angular deformity (procurvatum) in the distal third of the tibia. A closing wedge osteotomy is planned. To accurately realign the mechanical axis without creating translation of the bone ends, the hinge must be placed on the transverse bisector line of the CORA. How is the CORA geometrically defined in this simple uniapical deformity?

. The intersection of the mechanical axes of the femur and tibia
. The center point of the ankle joint mortise
. The intersection of the proximal and distal mid-diaphyseal anatomical axes
. The most prominent point on the anterior cortex of the tibia
. The point exactly mid-way between the knee and ankle joints

Correct Answer & Explanation

. The intersection of the proximal and distal mid-diaphyseal anatomical axes

Explanation

By definition, the CORA is the point where the proximal and distal mechanical or anatomical axes intersect. Placing the hinge on the bisector line of this intersection allows angular correction without secondary translation.

Question 9538

Topic: Lower Extremity Trauma

A patient presents with medial mechanical axis deviation (MAD) causing varus gonarthrosis. Preoperative full-length standing radiographs reveal a mechanical lateral distal femoral angle (mLDFA) of 98 degrees (normal 87) and a medial proximal tibial angle (MPTA) of 87 degrees (normal 87). Joint line convergence angle (JLCA) is 2 degrees. Based on Paley's principles of joint orientation, where is the primary source of the deformity?

. Proximal tibia
. Distal femur
. Knee joint collateral ligaments (laxity)
. Proximal femur
. Ankle joint

Correct Answer & Explanation

. Distal femur

Explanation

The source of the mechanical axis deviation is identified by abnormal joint orientation angles. An increased mLDFA (98 degrees) indicates a distal femoral varus deformity, while the normal MPTA and JLCA rule out the tibia and ligamentous laxity as primary causes.

Question 9539

Topic: 2. Trauma

An infant is brought to the orthopedic clinic with an anterolateral bowing of the left tibia noted shortly after birth. The mother has multiple cafe-au-lait spots and axillary freckling. Which of the following is the most appropriate initial management for the tibial deformity to prevent pseudarthrosis?

. Immediate prophylactic intramedullary nailing
. Posteromedial release of the ankle and foot
. Early osteotomy and corrective plating
. Application of a total contact orthosis (clam-shell brace)
. Observation with serial radiographs every 6 months without bracing

Correct Answer & Explanation

. Application of a total contact orthosis (clam-shell brace)

Explanation

Correct Answer: Application of a total contact orthosis (clam-shell brace)The infant has anterolateral bowing of the tibia, which is highly associated with Neurofibromatosis type 1 (NF1) and is a precursor to congenital pseudarthrosis of the tibia (CPT). The dysplastic, anarchic fibrous tissue in the periosteum impairs normal bone healing. The initial management of anterolateral bowing before a fracture occurs is strict protection with a total contact orthosis (such as a clam-shell brace or AFO) to prevent fracture. Prophylactic surgery (nailing or osteotomy) is generally avoided until a fracture occurs or deformity is severe, as surgery itself can precipitate the pseudarthrosis.

Question 9540

Topic: 2. Trauma
A 3-year-old child with multiple café-au-lait spots (smooth borders) and axillary freckling presents with anterolateral bowing of the left tibia. Radiographs show medullary sclerosis and a cystic pre-pseudarthrosis lesion, but no frank fracture. What is the most appropriate initial management strategy to prevent progression to frank pseudarthrosis?
. Application of a total contact orthosis (clam-shell brace) and close observation.
. Immediate resection of the dysplastic segment and vascularized fibular graft.
. Prophylactic intramedullary rodding and bone grafting.
. Epiphysiodesis of the contralateral limb to prevent leg length discrepancy.
. Administration of intravenous bisphosphonates.

Correct Answer & Explanation

. Application of a total contact orthosis (clam-shell brace) and close observation.

Explanation

This child has Neurofibromatosis type 1 (NF1) with anterolateral bowing of the tibia, a classic pre-pseudarthrosis lesion. The initial management of anterolateral bowing before a fracture occurs is prophylactic bracing (e.g., a total contact clam-shell orthosis or AFO) to protect the limb and delay or prevent fracture. Surgical intervention (such as IM rodding, resection, and grafting) is generally reserved for when a frank fracture and pseudarthrosis occur, as prophylactic surgery has a high failure rate and can precipitate the pseudarthrosis it aims to prevent.

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