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2. Trauma MCQs

Practice Set 53 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 1041

Topic: 2. Trauma

Following intramedullary nailing for the proximal tibial diaphyseal fracture, the patient is in the immediate postoperative period.

What is the MOST critical immediate postoperative concern that requires extreme vigilance and hourly monitoring in this patient?

. Deep vein thrombosis (DVT)
. Surgical site infection (SSI)
. Delayed union
. Delayed acute compartment syndrome
. Hardware failure

Correct Answer & Explanation

. Delayed acute compartment syndrome

Explanation

Correct Answer: DThe case explicitly states: 'The immediate postoperative period requires extreme vigilance for the development of delayed acute compartment syndrome. The trauma of reaming and nail insertion introduces additional volume and inflammatory mediators into the closed fascial spaces. The patient was admitted to the orthopedic trauma unit with strict instructions for hourly neurovascular and compartment checks for the first 24 hours.' While DVT, SSI, delayed union, and hardware failure are all potential complications, delayed acute compartment syndrome is the most immediate, life-threatening, and limb-threatening complication requiring hourly monitoring in the immediate postoperative period, as emphasized in the case.

Question 1042

Topic: 2. Trauma

A 28-year-old male presents to the trauma center after a high-energy motor vehicle collision, sustaining an open right tibial diaphyseal fracture. Despite initial hemodynamic stability and palpable distal pulses, he develops excruciating, unremitting pain in his right lower leg, rated 10/10 on the VAS, unresponsive to high-dose opioids. Clinical examination reveals a tense, 'wood-hard' anterior compartment. Which of the following is the MOST sensitive and specific clinical finding for diagnosing acute compartment syndrome in this patient?

. A. Absence of distal pulses (dorsalis pedis and posterior tibial)
. B. Pallor and poikilothermia of the affected limb
. C. Severe pain with passive plantarflexion of the ankle and passive flexion of the great toe
. D. Paresthesia in the distribution of the superficial peroneal nerve
. E. Gross deformity and crepitus at the fracture site

Correct Answer & Explanation

. C. Severe pain with passive plantarflexion of the ankle and passive flexion of the great toe

Explanation

Correct Answer: CExplanation:The most sensitive and specific clinical finding for diagnosing acute compartment syndrome (ACS) is severe pain with passive stretch of the muscles within the affected compartment, which is disproportionate to the injury and unrelieved by analgesia. In this case, passive plantarflexion of the ankle and passive flexion of the great toe selectively stretch the muscles of the anterior compartment (tibialis anterior, extensor hallucis longus, extensor digitorum longus), eliciting excruciating pain. This is a hallmark sign of ACS.A. Absence of distal pulses (dorsalis pedis and posterior tibial):Pulselessness is a very late and unreliable sign of ACS. Peripheral pulses are often maintained until intra-compartmental pressure exceeds systolic arterial pressure, which signifies irreversible damage. The case explicitly states that distal pulses remained robust and palpable, highlighting this pitfall.B. Pallor and poikilothermia of the affected limb:These are classic signs of acute arterial occlusion/ischemia, not typically ACS. In ACS, the limb is often warm due to the hyperemic response of early tissue distress, and pallor is not a primary feature until very late stages.D. Paresthesia in the distribution of the superficial peroneal nerve:While sensory changes (paresthesia, diminished two-point discrimination) are important signs of nerve ischemia in ACS, they are generally considered less sensitive and specific than pain with passive stretch, and often represent a more advanced stage of nerve compromise. The case describes this as altered sensation progressing to early paresthesia, indicating it's an evolving sign.E. Gross deformity and crepitus at the fracture site:Gross deformity and crepitus are expected findings with a displaced tibial fracture. They are indicative of the fracture itself, not specifically acute compartment syndrome. While the fracture is the inciting event, these findings do not differentiate between a simple fracture and one complicated by ACS.

Question 1043

Topic: 2. Trauma

The patient's clinical presentation, including escalating pain, tense compartments, and severe pain with passive stretch, led to a clinical diagnosis of acute compartment syndrome. Given the high-energy mechanism and open fracture, which of the following conditions would be the MOST critical to differentiate from acute compartment syndrome, and what specific finding in this case helped rule it out?

. A. Deep Vein Thrombosis (DVT); absence of Homan's sign
. B. Necrotizing Fasciitis; absence of crepitus and systemic toxicity
. C. Acute Arterial Occlusion; presence of palpable distal pulses and brisk capillary refill
. D. Severe Fracture Pain; pain unresponsive to high-dose opioids and disproportionate to injury
. E. Peripheral Neuropathy; intact light touch sensation in multiple nerve distributions

Correct Answer & Explanation

. C. Acute Arterial Occlusion; presence of palpable distal pulses and brisk capillary refill

Explanation

Correct Answer: CExplanation:In the setting of high-energy trauma to an extremity, acute arterial occlusion is a limb-threatening emergency that must be rapidly differentiated from acute compartment syndrome. Both can present with severe pain and potential neurological deficits. However, the case explicitly states that the dorsalis pedis and posterior tibial pulses remained robust and palpable, and capillary refill was brisk (<2 seconds). This strongly rules out a major arterial occlusion as the primary pathology.A. Deep Vein Thrombosis (DVT); absence of Homan's sign:DVT typically presents with generalized swelling, dull aching pain, and erythema, usually developing over a longer period (hours to days) than the acute timeline of this injury. While Homan's sign is unreliable, the acute onset and localized compartment tenseness are inconsistent with DVT.B. Necrotizing Fasciitis; absence of crepitus and systemic toxicity:Necrotizing fasciitis is a severe soft tissue infection. While it causes severe pain, it is typically accompanied by systemic signs of sepsis (fever, tachycardia), crepitus (indicating gas-forming organisms), and hemorrhagic bullae, which were not present in this acute setting.D. Severe Fracture Pain; pain unresponsive to high-dose opioids and disproportionate to injury:While severe fracture pain is a differential, the key differentiating factor from ACS is that fracture pain is usually proportional to the injury and improves with immobilization and analgesia. The patient's pain was 'excruciating, unremitting,' '10/10 on the VAS,' and 'completely unrelieved' by high-dose opioids, which strongly points away from isolated fracture pain and towards ACS. However, this option describes a finding thatconfirmsACS rather than ruling out a critical differential.E. Peripheral Neuropathy; intact light touch sensation in multiple nerve distributions:Peripheral neuropathy is a chronic condition and not an acute traumatic differential. While nerve injury can occur with trauma, the initial intact sensation followed by rapid deterioration points to an acute ischemic process, not a pre-existing neuropathy.

Question 1044

Topic: 2. Trauma
Given the patient's clear clinical signs of acute compartment syndrome, the decision was made to proceed directly to surgery without intra-compartmental pressure monitoring. However, in an equivocal case, such as an obtunded or polytraumatized patient, pressure monitoring would be indicated. Which of the following pressure measurements is the most reliable indicator for emergent fasciotomy?
. Absolute intra-compartmental pressure greater than 30 mmHg
. Absolute intra-compartmental pressure greater than 40 mmHg
. A Delta P (Diastolic Blood Pressure - Intra-compartmental Pressure) less than 30 mmHg
. A Delta P (Systolic Blood Pressure - Intra-compartmental Pressure) less than 30 mmHg
. A Delta P (Mean Arterial Pressure - Intra-compartmental Pressure) less than 40 mmHg

Correct Answer & Explanation

. A Delta P (Diastolic Blood Pressure - Intra-compartmental Pressure) less than 30 mmHg

Explanation

The most reliable indicator for emergent fasciotomy, especially in equivocal cases or non-communicative patients, is the differential pressure (Delta P). Delta P is calculated as Diastolic Blood Pressure (DBP) minus the Intra-compartmental Pressure (ICP). A Delta P of less than 30 mmHg signifies inadequate tissue perfusion and is a widely accepted threshold for emergent fasciotomy. This metric accounts for the patient's systemic blood pressure, which is crucial because a hypotensive patient with a relatively low absolute compartment pressure can still be ischemic, while a hypertensive patient with a higher absolute compartment pressure might maintain adequate perfusion.

Question 1045

Topic: 2. Trauma

The patient underwent emergent dual-incision four-compartment fasciotomy and unreamed intramedullary nailing. The case highlights the critical time sensitivity of acute compartment syndrome. Skeletal muscle can tolerate ischemia for approximately 4 hours without permanent damage. Between 4 and 8 hours, irreversible myonecrosis and peripheral nerve damage begin to occur. Beyond 8 hours, the damage is essentially complete. What is the primary cellular mechanism underlying irreversible damage in acute compartment syndrome?

. A. Excessive calcium influx leading to muscle hypercontracture and rigor mortis
. B. Failure of the ATP-dependent Na+/K+ pump, leading to intracellular swelling and cell death
. C. Accumulation of lactic acid causing severe acidosis and enzyme denaturation
. D. Direct mechanical compression of muscle fibers leading to necrosis
. E. Reperfusion injury causing massive free radical production and inflammation

Correct Answer & Explanation

. B. Failure of the ATP-dependent Na+/K+ pump, leading to intracellular swelling and cell death

Explanation

Correct Answer: BExplanation:The primary cellular mechanism underlying irreversible damage in acute compartment syndrome is the failure of the ATP-dependent Na+/K+ pump. As intra-compartmental pressure rises, it compromises capillary perfusion, leading to tissue ischemia and cellular hypoxia. Without adequate oxygen, cells cannot produce sufficient ATP through oxidative phosphorylation. The Na+/K+ pump, which actively transports sodium out of the cell and potassium into the cell, is highly ATP-dependent. Its failure leads to an accumulation of sodium and water inside the cell, causing intracellular swelling. This swelling further exacerbates the intra-compartmental pressure in a vicious cycle, ultimately leading to cell membrane rupture and myonecrosis.A. Excessive calcium influx leading to muscle hypercontracture and rigor mortis:While calcium dysregulation (influx of calcium) does occur in ischemic cells and contributes to muscle damage and hypercontracture, it is a downstream effect of the initial energy failure and membrane dysfunction, not the primary initiating mechanism of irreversible damage.C. Accumulation of lactic acid causing severe acidosis and enzyme denaturation:Lactic acid accumulation and acidosis are consequences of anaerobic metabolism during ischemia. While acidosis contributes to cellular dysfunction, the fundamental irreversible damage stems from the failure of ion pumps and subsequent cellular swelling and membrane integrity loss.D. Direct mechanical compression of muscle fibers leading to necrosis:While there is mechanical compression, the primary mechanism of damage is ischemic, not purely mechanical. The pressure impedes blood flow, leading to hypoxia, which then triggers the cellular cascade of pump failure and swelling.E. Reperfusion injury causing massive free radical production and inflammation:Reperfusion injury is a significant complication that occursafterfasciotomy when blood flow is restored to ischemic tissues. It involves the production of reactive oxygen species (free radicals) and inflammatory mediators, which can cause further tissue damage and systemic complications (e.g., rhabdomyolysis, acute kidney injury). However, it is not the mechanism of irreversible damageduringthe ischemic phase of ACS.

Question 1046

Topic: 2. Trauma

The patient underwent a dual-incision four-compartment fasciotomy. The surgical image below shows a typical anterolateral incision for fasciotomy. During the anterolateral incision, which nerve is at greatest risk of iatrogenic injury, and where is it typically located?

. A. Tibial nerve; deep posterior compartment, posterior to the tibialis posterior muscle
. B. Common peroneal nerve; wrapping around the fibular neck, proximal to the lateral compartment release
. C. Superficial peroneal nerve; exiting the lateral compartment fascia in the distal third of the leg
. D. Deep peroneal nerve; running with the anterior tibial artery in the anterior compartment
. E. Saphenous nerve; in the subcutaneous tissue along the posteromedial aspect of the leg

Correct Answer & Explanation

. C. Superficial peroneal nerve; exiting the lateral compartment fascia in the distal third of the leg

Explanation

Correct Answer: CExplanation:During the anterolateral incision for fasciotomy, the superficial peroneal nerve is at greatest risk of iatrogenic injury. It typically exits the lateral compartment fascia to become subcutaneous in the distal third of the leg, approximately 10 to 12 cm proximal to the lateral malleolus. Care must be taken during the distal extension of the lateral compartment fascial release to identify and protect this nerve, as injury can lead to sensory loss over the lateral dorsum of the foot and potentially a painful neuroma.A. Tibial nerve; deep posterior compartment, posterior to the tibialis posterior muscle:The tibial nerve is located in the deep posterior compartment and is at risk during the posteromedial incision and deep posterior compartment release, not the anterolateral incision.B. Common peroneal nerve; wrapping around the fibular neck, proximal to the lateral compartment release:The common peroneal nerve is at risk during the proximal extension of the lateral compartment fascial release, particularly when incising near the fibular head. While important to protect, the superficial peroneal nerve is more commonly injured during the distal aspect of the anterolateral incision due to its superficial course.D. Deep peroneal nerve; running with the anterior tibial artery in the anterior compartment:The deep peroneal nerve is located within the anterior compartment. While it is important to avoid direct injury to this nerve during the anterior compartment release, it is generally less susceptible to iatrogenic injury from the fascial incision itself compared to the superficial peroneal nerve, which becomes subcutaneous.E. Saphenous nerve; in the subcutaneous tissue along the posteromedial aspect of the leg:The saphenous nerve is located in the subcutaneous tissue along the posteromedial aspect of the leg and is at risk during the posteromedial incision, not the anterolateral incision.

Question 1047

Topic: 2. Trauma

Following the emergent four-compartment fasciotomy, the open tibial fracture (Gustilo-Anderson Type II, OTA/AO 42-B3) required stabilization. The patient was physiologically stable. The surgical team opted for unreamed statically locked intramedullary nailing. Which of the following is the MOST compelling reason for choosing unreamed intramedullary nailing over spanning external fixation in this specific clinical scenario?

. A. External fixation is contraindicated in open fractures due to high infection rates.
. B. Unreamed intramedullary nailing provides superior biomechanical stability and avoids pin-tract complications, facilitating earlier definitive soft tissue coverage.
. C. Reamed intramedullary nailing is preferred for open fractures to enhance fracture healing.
. D. External fixation would further elevate intra-compartmental pressures after fasciotomy.
. E. Unreamed nailing allows for immediate full weight-bearing, accelerating rehabilitation.

Correct Answer & Explanation

. B. Unreamed intramedullary nailing provides superior biomechanical stability and avoids pin-tract complications, facilitating earlier definitive soft tissue coverage.

Explanation

Correct Answer: BExplanation:In a physiologically stable patient with an open tibial fracture and acute compartment syndrome, unreamed intramedullary nailing offers several advantages over external fixation. It provides superior biomechanical stability, which is crucial for fracture healing and allows for earlier mobilization. Furthermore, it avoids the complications associated with external fixator pin tracts, such as pin-tract infections, which can complicate subsequent definitive soft tissue coverage and potentially lead to osteomyelitis. The case explicitly states that modern trauma protocols often favor early definitive fixation with an unreamed IMN if the patient is physiologically stable, as it provides superior biomechanical stability and avoids pin-tract infections.A. External fixation is contraindicated in open fractures due to high infection rates:External fixation is a valid and often preferred method for initial stabilization of open fractures, especially in unstable patients (damage control orthopedics). While pin-tract infections are a concern, it is not an absolute contraindication for open fractures.C. Reamed intramedullary nailing is preferred for open fractures to enhance fracture healing:Reaming the medullary canal can further disrupt endosteal blood supply and potentially increase intra-compartmental pressures, especially in the context of recent fasciotomy. Therefore, unreamed nailing is generally preferred in open fractures and those complicated by ACS to minimize additional soft tissue and vascular insult.D. External fixation would further elevate intra-compartmental pressures after fasciotomy:External fixation itself does not typically elevate intra-compartmental pressures after a successful fasciotomy. The concern with external fixation relates more to pin-site issues and less stable fixation compared to IMN.E. Unreamed nailing allows for immediate full weight-bearing, accelerating rehabilitation:While IMN provides good stability, a comminuted diaphyseal fracture (OTA 42-B3) fixed with an unreamed nail typically requires a period of protected weight-bearing (e.g., touch-down weight-bearing for 6 weeks, as described in the case) to allow for callus formation and prevent implant failure. Immediate full weight-bearing is generally not advised.

Question 1048

Topic: 2. Trauma

The patient's postoperative course included aggressive intravenous fluid resuscitation to maintain a high urine output and monitoring of serum creatine kinase (CK) levels. This management strategy is primarily aimed at preventing which of the following complications?

. A. Deep vein thrombosis (DVT)
. B. Acute respiratory distress syndrome (ARDS)
. C. Acute kidney injury (AKI) secondary to rhabdomyolysis
. D. Compartment syndrome recurrence
. E. Wound infection and dehiscence

Correct Answer & Explanation

. C. Acute kidney injury (AKI) secondary to rhabdomyolysis

Explanation

Correct Answer: CExplanation:Aggressive intravenous fluid resuscitation and monitoring of serum creatine kinase (CK) levels post-fasciotomy are critical for preventing acute kidney injury (AKI) secondary to rhabdomyolysis. Rhabdomyolysis is the breakdown of damaged muscle tissue, releasing myoglobin into the bloodstream. Myoglobin is nephrotoxic and can precipitate in the renal tubules, leading to acute tubular necrosis and AKI. Maintaining a high urine output helps to flush myoglobin through the renal tubules, while monitoring CK levels tracks the extent of muscle breakdown.A. Deep vein thrombosis (DVT):While DVT prophylaxis is important in trauma patients, aggressive fluid resuscitation is not its primary treatment or prevention strategy.B. Acute respiratory distress syndrome (ARDS):ARDS is a severe lung injury that can occur in polytrauma patients, but it is not directly addressed by fluid resuscitation for rhabdomyolysis.D. Compartment syndrome recurrence:Compartment syndrome recurrence is prevented by ensuring a complete fasciotomy and leaving the wounds open. While fluid management is crucial for systemic health, it does not directly prevent recurrence of local compartment pressure.E. Wound infection and dehiscence:Wound infection is managed with antibiotics, meticulous debridement, and proper wound care. Dehiscence is prevented by delayed primary closure or skin grafting when edema has resolved. Fluid resuscitation is not the primary intervention for these wound complications.

Question 1049

Topic: 2. Trauma
The patient sustained an open right tibial diaphyseal fracture. The laceration was 2 cm, without extensive soft tissue damage, avulsions, or degloving, and with adequate soft tissue coverage for the bone. Based on this description, what is the correct Gustilo-Anderson classification for this open fracture?
. Gustilo-Anderson Type I
. Gustilo-Anderson Type II
. Gustilo-Anderson Type IIIA
. Gustilo-Anderson Type IIIB
. Gustilo-Anderson Type IIIC

Correct Answer & Explanation

. Gustilo-Anderson Type II

Explanation

The Gustilo-Anderson classification system categorizes open fractures based on the size of the wound, the extent of soft tissue damage, and the degree of contamination. In this case, the laceration was 2 cm, which is greater than 1 cm but without extensive soft tissue damage, avulsions, or degloving, and with adequate soft tissue coverage for the bone. This description perfectly matches the criteria for a Gustilo-Anderson Type II open fracture.

Question 1050

Topic: 2. Trauma
The case emphasizes a critical clinical pearl: 'Open fractures do not prevent compartment syndrome.' Which of the following statements best explains why an open tibial fracture, even with a visible laceration, does not reliably decompress the fascial compartments and prevent acute compartment syndrome?
. The fascial defect in an open fracture is rarely large enough to allow sufficient extrusion of hematoma and edematous muscle to lower intra-compartmental pressure below the ischemic threshold.
. Open fractures inherently cause more severe arterial injury, leading to compartment syndrome.
. The presence of an open wound increases the risk of infection, which directly causes compartment syndrome.
. Open fractures lead to systemic hypotension, which lowers the Delta P and precipitates compartment syndrome.
. The bone fragments in an open fracture directly compress the muscles, causing compartment syndrome regardless of fascial integrity.

Correct Answer & Explanation

. The fascial defect in an open fracture is rarely large enough to allow sufficient extrusion of hematoma and edematous muscle to lower intra-compartmental pressure below the ischemic threshold.

Explanation

The statement 'Open fractures do not prevent compartment syndrome' is a crucial clinical pearl. The primary reason is that the fascial defect created by an open fracture, even if visible, is rarely large enough or strategically located to allow for sufficient decompression of the entire fascial compartment. The non-yielding osseous-fascial envelope remains largely intact, trapping the accumulating hematoma and edematous muscle, leading to a rise in intra-compartmental pressure above the ischemic threshold.

Question 1051

Topic: 2. Trauma

The patient's radiographs, shown below, revealed a displaced, comminuted fracture of the middle and distal third junction of the right tibial diaphysis, classified as an OTA/AO 42-B3. This was associated with a segmental fracture of the fibular diaphysis. What does the 'B3' in the OTA/AO classification for the tibia specifically indicate?

. A. A simple spiral fracture of the tibia
. B. A multifragmentary segmental fracture of the tibia
. C. A wedge fracture with a fragmented wedge
. D. A complex comminuted fracture with bone loss
. E. An intra-articular fracture extending into the ankle joint

Correct Answer & Explanation

. C. A wedge fracture with a fragmented wedge

Explanation

Correct Answer: CExplanation:The OTA/AO classification system for long bone fractures is hierarchical. For the tibia (bone 4), diaphyseal fractures are group 2. The 'B' indicates a wedge fracture, meaning there is a third fragment (a wedge) that is still in contact with one of the main fragments after reduction. The '3' further specifies the type of wedge. A 'B3' fracture is a wedge fracture with a fragmented wedge, indicating a more comminuted and unstable wedge fragment compared to a simple wedge (B2).A. A simple spiral fracture of the tibia:A simple spiral fracture would typically be classified as an A1 fracture (simple, spiral).B. A multifragmentary segmental fracture of the tibia:A segmental fracture (two distinct fracture lines creating a free segment) would be classified as a C-type fracture (complex, multifragmentary).D. A complex comminuted fracture with bone loss:While the fracture is comminuted, 'bone loss' is not directly indicated by B3. Complex comminuted fractures are generally C-type fractures.E. An intra-articular fracture extending into the ankle joint:Intra-articular fractures are classified differently (e.g., 43-A, B, C for distal tibia). The '42' indicates a diaphyseal fracture, not an intra-articular one.

Question 1052

Topic: 2. Trauma

A 32-year-old male undergoes intramedullary nailing for a proximal third tibia shaft fracture via an infrapatellar approach. Postoperatively, what is the most common malalignment seen in this fracture pattern using this specific surgical approach?

. Valgus and procurvatum
. Varus and procurvatum
. Valgus and recurvatum
. Varus and recurvatum
. Shortening and internal rotation

Correct Answer & Explanation

. Valgus and procurvatum

Explanation

Proximal third tibia fractures treated with an infrapatellar IM nail classically fall into valgus and procurvatum. This is due to the anterior pull of the patellar tendon on the proximal fragment and the anatomical wedge effect of the posterior metaphyseal cortex.

Question 1053

Topic: 2. Trauma

To prevent the classic valgus and procurvatum deformity during intramedullary nailing of a proximal third tibia fracture, where should the blocking (Poller) screws be placed relative to the central axis of the medullary canal in the proximal segment?

. Medial and anterior
. Lateral and posterior
. Medial and posterior
. Lateral and anterior
. Distal and posterior

Correct Answer & Explanation

. Lateral and posterior

Explanation

Poller screws act as an artificial cortex to direct the nail path. To prevent valgus and procurvatum in proximal fractures, they must be placed on the concave side of the deformity, which corresponds to the lateral and posterior aspects of the proximal fragment.

Question 1054

Topic: 2. Trauma

A 25-year-old male is intubated following a motorcycle crash and has a closed midshaft tibia fracture. Compartment pressures are measured. Which of the following thresholds is the most universally accepted absolute indication for a four-compartment fasciotomy?

. Absolute compartment pressure > 20 mmHg
. Absolute compartment pressure > 30 mmHg
. Delta P (Diastolic BP minus compartment pressure) < 30 mmHg
. Delta P (Mean arterial pressure minus compartment pressure) < 30 mmHg
. Delta P (Systolic BP minus compartment pressure) < 40 mmHg

Correct Answer & Explanation

. Delta P (Diastolic BP minus compartment pressure) < 30 mmHg

Explanation

A Delta P (diastolic blood pressure minus compartment pressure) of less than 30 mmHg is the most reliable and universally accepted threshold for diagnosing acute compartment syndrome and indicates emergent fasciotomies.

Question 1055

Topic: 2. Trauma
Based on the findings of the SPRINT (Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Fractures) trial, what is the primary conclusion regarding reamed versus unreamed intramedullary nailing?
. Unreamed nails have lower infection rates in open fractures.
. Reamed nails significantly increase the risk of compartment syndrome.
. Reamed nails have a lower rate of nonunion requiring secondary intervention in closed fractures.
. Unreamed nails lead to faster union times in closed fractures.
. There is no difference in secondary reoperation rates between the two techniques for either open or closed fractures.

Correct Answer & Explanation

. Reamed nails have a lower rate of nonunion requiring secondary intervention in closed fractures.

Explanation

The SPRINT trial demonstrated that reamed IM nailing significantly decreased the rate of secondary interventions for delayed union or nonunion in closed tibia fractures compared to unreamed nails, with no significant outcome difference for open fractures.

Question 1056

Topic: 2. Trauma

A 40-year-old male presents to the ED 48 hours after a crush injury to his right leg. The leg is woody, cold, and pulseless with profound motor and sensory deficits. Renal labs show severe myoglobinuria. What is the most appropriate management of the lower extremity?

. Emergent four-compartment fasciotomy
. Non-operative management focusing on hydration and alkalinization of urine
. Immediate application of an external fixator
. Prophylactic fasciotomies of the contralateral leg
. Thrombolytic therapy

Correct Answer & Explanation

. Non-operative management focusing on hydration and alkalinization of urine

Explanation

Fasciotomy is generally contraindicated in late presentations (>24-48 hours) with established, irreversible muscle necrosis due to the exceptionally high risk of infection and sepsis. Management focuses on life-saving systemic support like preventing renal failure, though amputation may eventually be required.

Question 1057

Topic: 2. Trauma

During intramedullary nailing of a distal third tibia fracture, the surgeon notes valgus malalignment at the fracture site upon nail insertion. Which of the following technical errors most commonly contributes to this specific deformity?

. A starting point that is too lateral
. Over-reaming the diaphysis
. A starting point that is too medial
. Use of a nail with a Herzog bend
. Failure to ream to the subchondral bone

Correct Answer & Explanation

. A starting point that is too medial

Explanation

In distal third tibia fractures, a starting point that is too medial, or a trajectory directed laterally, causes the nail to glance off the lateral cortex of the distal segment. This drives the distal fragment into valgus malalignment.

Question 1058

Topic: 2. Trauma

Which of the following is a primary biomechanical advantage of the suprapatellar approach for tibial intramedullary nailing compared to the traditional infrapatellar approach?

. Reduced risk of anterior knee pain at 2 years postoperatively
. Elimination of the need for intraoperative fluoroscopy
. Decreased incidence of postoperative compartment syndrome
. Easier maintenance of reduction in proximal third fractures due to the semi-extended knee position
. Avoidance of an intra-articular trajectory

Correct Answer & Explanation

. Easier maintenance of reduction in proximal third fractures due to the semi-extended knee position

Explanation

The suprapatellar approach allows the leg to remain in a semi-extended position, relaxing the extensor mechanism. This significantly improves the ease of obtaining and maintaining reduction, particularly in proximal third tibia fractures.

Question 1059

Topic: 2. Trauma
A 24-year-old male sustains a Gustilo-Anderson Type IIIB open tibia fracture. According to current evidence-based guidelines, which of the following is the most critical initial intervention to prevent deep infection?
. Time to operative debridement within 6 hours of injury
. Early administration of appropriate intravenous antibiotics
. Immediate use of high-pressure pulsatile lavage in the emergency department
. Immediate internal fixation with a reamed intramedullary nail
. Routine application of a negative pressure wound therapy device

Correct Answer & Explanation

. Early administration of appropriate intravenous antibiotics

Explanation

Early administration of appropriate intravenous antibiotics is the single most critical factor in reducing the risk of infection in open fractures. The historic 6-hour rule for operative debridement has been shown to be less critical than prompt antibiotic delivery.

Question 1060

Topic: 2. Trauma

During a standard two-incision, four-compartment fasciotomy of the leg, the medial incision is utilized to release the superficial and deep posterior compartments. Releasing the deep posterior compartment carries the greatest risk of iatrogenic injury to which structure?

. Saphenous nerve
. Posterior tibial artery
. Sural nerve
. Superficial peroneal nerve
. Anterior tibial artery

Correct Answer & Explanation

. Posterior tibial artery

Explanation

The deep posterior compartment release requires dissecting the soleus attachments off the tibia. The neurovascular bundle, which includes the posterior tibial artery and tibial nerve, lies just posterior to the tibialis posterior muscle and is at high risk of iatrogenic injury.

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