Orthopedic Board Prep MCQs: Fracture & Trauma Part 44

Question 1

A 28-year-old male sustains a severe open right ankle injury following a motorcycle collision. In the emergency department, it is noted that his talus has been completely extruded and is missing. It is later recovered by paramedics at the scene. The talus is grossly intact but contaminated with soil. According to current orthopaedic trauma evidence, what is the most appropriate definitive management of the extruded talus?

Explanation

Historically, complete extrusion of the talus was treated with primary talectomy due to high expected rates of infection and avascular necrosis. However, modern evidence supports rigorous decontamination (copious sequential irrigation and debridement) followed by reimplantation. Multiple recent case series have demonstrated lower-than-expected rates of deep infection and clinically significant AVN, making reimplantation a viable and favored salvage option.

Question 2

A 45-year-old male presents with a pelvic ring injury and an associated acetabular fracture. An obturator oblique plain radiograph demonstrates the classic 'spur sign'. What anatomical structure does this radiographic sign represent?

Explanation

The 'spur sign' is a classic radiographic finding seen on the obturator oblique view in both-column acetabular fractures. It represents the intact portion of the posterior ilium (strut of the axial skeleton) extending inferiorly, relative to the medially and internally displaced articular fracture segments.

Question 3

Which of the following findings is the most reliable predictor of a poor long-term functional outcome in a patient diagnosed with scapulothoracic dissociation?

Explanation

Scapulothoracic dissociation is a devastating injury characterized by complete disruption of the scapulothoracic articulation. While vascular injuries (subclavian artery) are life-threatening and dictate immediate surgical priorities, the long-term functional outcome of the limb is most heavily dependent on the neurologic status. A complete brachial plexus avulsion is the most reliable predictor of a flail, functionless limb, often eventually requiring a forequarter amputation.

Question 4

A 30-year-old male sustains a Pauwels type III femoral neck fracture (70-degree vertical shear angle). Biomechanical studies suggest that which of the following internal fixation constructs provides the greatest stability against vertical shear forces for this fracture pattern?

Explanation

Pauwels type III femoral neck fractures in young adults have a high vertical orientation, exposing them to massive shear forces and a high risk of varus collapse/nonunion. Biomechanical studies have consistently shown that a fixed-angle device, such as a sliding hip screw (SHS) combined with an anti-rotation (derotation) screw, provides superior resistance to vertical shear compared to multiple cancellous screws.

Question 5

A 35-year-old female sustains an isolated lateral Hoffa fracture (coronal shear fracture of the lateral femoral condyle). To achieve the most biomechanically stable fixation, in which direction should the primary lag screws be inserted?

Explanation

A Hoffa fracture is a coronal shear fracture of the femoral condyle (most commonly lateral). Biomechanically, posterior-to-anterior (PA) lag screw placement is stronger than anterior-to-posterior (AP) placement. This is because PA screws allow the screw head to purchase the smaller posterior fragment, achieving optimal interfragmentary compression against the larger, stable anterior segment. AP screws rely on thread purchase in the relatively small and often osteoporotic posterior fragment, which has a higher risk of pull-out.

Question 6

A patient with a diaphyseal tibia fracture complains of escalating, severe leg pain. The clinical team suspects acute compartment syndrome. The patient's blood pressure is 115/65 mmHg (MAP 82 mmHg). Continuous compartment pressure monitoring is initiated. According to McQueen et al., an absolute indication for emergent fasciotomy is a Delta P (ΔP) below what threshold, and how is it calculated?

Explanation

The diagnosis of acute compartment syndrome using intracompartmental pressure monitoring is most reliably determined by the Delta P (ΔP) concept. McQueen established that a ΔP of less than 30 mmHg is the threshold for emergent fasciotomy. ΔP is calculated as Diastolic Blood Pressure minus Compartment Pressure. MAP and absolute compartment pressures (e.g., >30 mmHg alone) are less reliable due to variations in systemic perfusion pressure.

Question 7

A 40-year-old male sustains a high-energy floating shoulder injury (ipsilateral clavicle and scapular neck fractures). Measurement of the glenopolar angle (GPA) on an AP radiograph of the shoulder is considered. Which of the following statements regarding the GPA is correct?

Explanation

The glenopolar angle (GPA) assesses rotational malalignment of the glenoid in scapular neck fractures. It is the angle formed by a line connecting the superior and inferior glenoid rims and a line connecting the superior glenoid rim to the inferior angle of the scapula. Normal GPA is 30 to 45 degrees. A severely decreased GPA (typically < 20-22 degrees) implies severe inferior tilt of the glenoid and is widely accepted as an indication for operative fixation to prevent chronic shoulder dysfunction.

Question 8

A 55-year-old female presents with a severely displaced proximal humerus fracture. According to Hertel's radiographic criteria, which combination of findings is the most highly predictive of subsequent humeral head ischemia?

Explanation

Hertel described specific radiographic criteria predictive of humeral head ischemia (AVN) following proximal humerus fractures. The three strongest predictors are an anatomic neck fracture (disruption of the articular surface from the metaphysis), a short calcar segment attached to the head (<8 mm), and a disrupted medial hinge (medial shaft displaced >2 mm from the head). When all three are present, the positive predictive value for ischemia is 97%.

Question 9

A 25-year-old patient presents with an open Gustilo-Anderson IIIB distal-third tibial shaft fracture with massive anterior soft tissue loss. Bone stabilization is achieved with an intramedullary nail. Which of the following is the most appropriate definitive soft-tissue coverage option for this specific anatomic zone?

Explanation

For soft tissue coverage of the tibia, local rotational muscle flaps are generally defined by thirds: the proximal third is covered by the gastrocnemius, and the middle third by the soleus. The distal third of the tibia lacks adequate local muscle bulk for reliable rotational coverage. Therefore, severe soft tissue defects (Gustilo IIIB) in the distal third require free tissue transfer (free flap), such as an anterolateral thigh (ALT) or latissimus dorsi flap, for definitive coverage.

Question 10

In the surgical treatment of a displaced volar Barton's fracture (volar marginal shear fracture of the distal radius), failure to properly reduce and stabilize the volar lunate facet fragment most reliably leads to volar radiocarpal subluxation. This subluxation occurs due to the incompetence of which critical ligament attached to this fragment?

Explanation

The volar lunate facet of the distal radius serves as the origin for the short radiolunate ligament, which inserts onto the volar aspect of the lunate. This ligament is the primary restraint preventing volar translation of the lunate and the entire carpus. If the volar lunate facet fracture fragment is not rigidly stabilized with a volar buttress plate, the carpus will subluxate volarly.

Question 11

During the posteromedial approach to the tibial plateau for fixation of a complex medial plateau fracture-dislocation, the surgical interval is developed between which two anatomical structures?

Explanation

The posteromedial approach to the tibial plateau is the standard approach for isolated posteromedial shear fragments (e.g., Moore Type I). The internervous/intermuscular interval is developed by retracting the pes anserinus anteriorly and the medial head of the gastrocnemius posteriorly, exposing the underlying popliteus and posteromedial border of the tibia.

Question 12

A 65-year-old female who has been taking alendronate for 8 years presents with a non-traumatic thigh fracture. According to the revised 2013 American Society for Bone and Mineral Research (ASBMR) task force criteria, which of the following is an absolute MAJOR criterion required for the diagnosis of an atypical femoral fracture (AFF)?

Explanation

According to the ASBMR 2013 criteria for Atypical Femoral Fractures (AFF), major criteria must be present to diagnose an AFF. Major criteria include: location between the subtrochanteric region and supracondylar flare, associated with minimal/no trauma, transverse or short oblique configuration, noncomminuted or minimally comminuted, and localized periosteal/endosteal thickening of the lateral cortex (beaking). Bilateral symptoms, prodromal pain, and delayed healing are considered MINOR criteria.

Question 13

The Lower Extremity Assessment Project (LEAP) study comprehensively evaluated outcomes comparing limb salvage versus amputation for severe lower extremity trauma. At the 2-year follow-up, which of the following was a primary finding regarding functional outcomes based on the Sickness Impact Profile (SIP)?

Explanation

The LEAP study is a landmark multicenter prospective study evaluating severe limb trauma. Its most famous finding is that at 2 years, there is no significant difference in functional outcomes (as measured by SIP scores) between patients who underwent reconstruction/salvage versus those who underwent amputation. Furthermore, the study demonstrated that trauma scores (like the MESS) have low clinical utility for predicting the need for amputation or final functional outcome.

Question 14

A 70-year-old male undergoes evaluation for a periprosthetic total hip fracture. Radiographs demonstrate a displaced fracture around the distal tip of the femoral stem. The stem is radiographically loose, and there is severe proximal femoral bone loss and thinning of the cortices (<2 cm of intact diaphyseal bone). According to the Vancouver classification, what is the fracture type and the most appropriate standard surgical treatment?

Explanation

This scenario describes a Vancouver B3 periprosthetic fracture: the fracture occurs around the stem (B), the stem is loose (3), and there is poor bone stock (severe proximal bone loss). The standard of care for a Vancouver B3 fracture is revision arthroplasty using a modular, fluted, tapered stem bypassing the fracture, often supplemented with structural allografts, or utilizing a proximal femoral replacement (megaprosthesis) in older, lower-demand patients. B2 fractures involve a loose stem with GOOD bone stock and are treated with long stem revision.

Question 15

During the intrapelvic Stoppa approach for an acetabular fracture, the surgeon must be acutely aware of a major vascular anastomosis that frequently crosses over the superior pubic ramus at an average distance of 4 to 6 cm from the pubic symphysis. This structure, often termed the 'Corona Mortis', typically connects which two vascular systems?

Explanation

The Corona Mortis is an anastomotic arterial or venous connection between the obturator vessels (branching from the internal iliac system) and the external iliac or inferior epigastric vessels. It crosses the superior pubic ramus and is highly susceptible to iatrogenic injury during anterior intrapelvic approaches (e.g., Stoppa, ilioinguinal), which can result in life-threatening hemorrhage.

Question 16

A 6-year-old boy sustains a Gartland type III supracondylar humerus fracture. Upon arrival, his hand is pale and pulseless. He is immediately taken to the operating room, where closed reduction and percutaneous pinning are successfully performed. Following fixation, the hand becomes warm and pink with a capillary refill time of less than 2 seconds, but the radial pulse remains absent on palpation and Doppler ultrasound. What is the most appropriate next step in management?

Explanation

The 'pink, pulseless hand' following reduction and pinning of a pediatric supracondylar humerus fracture is a well-known clinical scenario. Current pediatric orthopaedic consensus and AAOS guidelines strongly recommend observation as long as the hand is well-perfused (warm, pink, capillary refill <2 seconds). Collateral circulation is robust in children, and the radial pulse often returns within days to weeks as vasospasm resolves. Emergent vascular exploration is reserved for hands that remain cold, white, and poorly perfused after reduction.

Question 17

According to the Sanders classification system for intra-articular calcaneal fractures, the severity and type of the fracture are determined by the number and location of articular fracture lines. Which specific imaging modality and slice dictates this classification?

Explanation

The Sanders classification is highly prognostic for functional outcomes in calcaneus fractures. It is based strictly on a coronal computed tomography (CT) image of the calcaneus, specifically the slice demonstrating the widest transverse dimension of the posterior facet of the subtalar joint. It categorizes fractures into types I-IV based on the number of fracture lines running through this facet.

Question 18

A 30-year-old male presents with a Maisonneuve fracture (a proximal third fibular fracture associated with an unstable syndesmotic injury). According to the Lauge-Hansen classification, this injury is best described as a Pronation-External Rotation (PER) stage 3 injury. What is the defining characteristic of the Stage 1 injury in this specific mechanistic sequence?

Explanation

In the Lauge-Hansen Pronation-External Rotation (PER) mechanism, the foot is pronated (placing tension on medial structures) before external rotation forces are applied. Thus, Stage 1 is a medial-sided injury: a transverse fracture of the medial malleolus or a rupture of the deltoid ligament. Stage 2 is rupture of the AITFL. Stage 3 is a high or mid-shaft spiral/oblique fibula fracture (e.g., Maisonneuve). Stage 4 is rupture of the PITFL or a posterior malleolus fracture.

Question 19

A 22-year-old male sustains a low-velocity gunshot wound to the right knee. Plain radiographs demonstrate a retained bullet entirely within the intra-articular space of the knee joint, with no associated fractures. Which of the following is the most appropriate long-term management strategy for the retained projectile?

Explanation

While many low-velocity gunshot wounds to soft tissue and bone can be managed non-operatively with local wound care and antibiotics, a bullet lodged within a synovial joint space is an absolute indication for surgical removal. If left in synovial fluid, the lead dissolves over time, leading to severe hypertrophic lead arthropathy (joint destruction) and systemic lead toxicity (plumbism).

Question 20

The Denis classification categorizes sacral fractures into three anatomic zones. Fractures involving which zone are associated with the highest incidence of neurologic deficits, including saddle anesthesia and bowel/bladder dysfunction?

Explanation

The Denis classification of sacral fractures comprises three zones: Zone 1 (ala, lateral to the foramina), Zone 2 (transforaminal), and Zone 3 (central sacral canal). Zone 3 fractures have the highest rate of significant neurologic deficit (>50%), frequently involving the lower sacral roots (S2-S4) and causing cauda equina syndrome, characterized by saddle anesthesia and loss of bowel and bladder sphincter control.

Question 21

The lateral extensile approach to the calcaneus utilizes an L-shaped incision. The blood supply to the vulnerable corner of this full-thickness flap is primarily derived from which of the following arteries?

Explanation

The lateral calcaneal artery, a branch of the peroneal artery, supplies the critical corner of the L-shaped extensile lateral flap. Injury to this vessel during dissection significantly increases the risk of wound edge necrosis.

Question 22

A 25-year-old male sustains a vertically oriented (Pauwels III) femoral neck fracture. Biomechanically, what is the primary advantage of a fixed-angle construct (e.g., sliding hip screw with derotation screw) over three parallel cannulated screws?

Explanation

A fixed-angle construct resists the high vertical shear forces inherent to Pauwels III fractures better than parallel cannulated screws. This minimizes inferior displacement, varus collapse, and subsequent nonunion.

Question 23

A polytrauma patient presents with hemodynamic instability and an anteroposterior compression (APC-III) pelvic ring injury. A circumferential pelvic binder is applied. To optimally reduce the pelvic volume and stabilize the fracture, the binder should be centered over which anatomical landmark?

Explanation

Pelvic binders must be centered directly over the greater trochanters to effectively close the pelvic ring and reduce intra-pelvic volume. Placing them higher over the iliac crests can inadvertently widen the true pelvis or fail to provide adequate compression.

Question 24

A 35-year-old patient sustains a 'terrible triad' injury of the elbow. Standard surgical protocol dictates a specific order of repair to restore stability. Which of the following represents the most accepted surgical sequence?

Explanation

The standard sequence for treating a terrible triad injury is to fix from deep to superficial. This involves restoring the anterior column (coronoid) first, followed by the radial head, and finally the lateral collateral ligament (LCL) complex.

Question 25

In a completely displaced proximal third subtrochanteric femur fracture, the proximal fragment is typically displaced in which of the following directions due to unresisted muscle forces?

Explanation

The proximal fragment is pulled into flexion by the iliopsoas, abduction by the gluteus medius and minimus, and external rotation by the short external rotators. Understanding these deforming forces is critical for obtaining an anatomic reduction during intramedullary nailing.

Question 26

A hemodynamically unstable trauma patient with an APC-III pelvic ring injury requires emergent pelvic binder application in the trauma bay. For maximum biomechanical efficacy, over which anatomic landmark should the binder be centered?

Explanation

Pelvic binders are most effective at reducing pelvic volume and stabilizing the ring when centered directly over the greater trochanters. Placement over the iliac crests is a common error and provides suboptimal reduction.

Question 27

A 25-year-old male sustains a severe closed tibial shaft fracture. You suspect acute compartment syndrome but the patient is obtunded. Which of the following intracompartmental pressure measurements represents the most reliable threshold for diagnosing compartment syndrome and proceeding with fasciotomy?

Explanation

The delta pressure (diastolic blood pressure minus intracompartmental pressure) is the most reliable physiologic indicator for compartment syndrome. A delta P of less than 30 mmHg is the widely accepted threshold indicating the need for emergent fasciotomy.

Question 28

A 22-year-old elite collegiate soccer player sustains an acute, non-displaced fracture at the metaphyseal-diaphyseal junction of the fifth metatarsal. What is the most appropriate management to minimize time off the field and reduce the risk of nonunion?

Explanation

Fractures at the metaphyseal-diaphyseal junction (Jones fractures) have a high rate of nonunion due to watershed vascularity. In high-level athletes, early intramedullary screw fixation significantly reduces nonunion risk and accelerates return to play compared to conservative management.

Question 29

A 40-year-old sustains a bicondylar tibial plateau fracture with a large, displaced posteromedial fragment. Through which anatomic interval is the standard posteromedial approach to the tibia performed?

Explanation

The posteromedial approach to the tibial plateau typically exploits the interval between the medial head of the gastrocnemius (which is retracted posteriorly) and the pes anserinus tendons (which are retracted anteriorly). This provides direct access to the posteromedial buttress.

Question 30

The Sanders classification is utilized for preoperative planning of intra-articular calcaneus fractures. This classification is based on the number and location of fracture lines viewed on which specific imaging sequence?

Explanation

The Sanders classification specifically evaluates the posterior facet of the calcaneus. It is based exclusively on the number and location of primary fracture lines seen on the coronal CT reconstruction at the widest point of the posterior facet.

Question 31

In a patient demonstrating the classic progression of scaphoid nonunion advanced collapse (SNAC), which specific area of the radiocarpal joint is characteristically spared from arthritic changes, even in the late stages of the disease?

Explanation

In both SNAC and SLAC wrist pathology, the radiolunate joint is characteristically spared from arthrosis. This is due to the congruent, concentric articulation between the lunate and the lunate fossa of the distal radius, which distributes loads evenly.

Question 32

A 65-year-old female on long-term alendronate therapy presents with progressively worsening prodromal thigh pain. Radiographs demonstrate lateral cortical thickening and a transverse radiolucent line in the subtrochanteric region of the femur. What is the most appropriate prophylactic management?

Explanation

This patient presents with a symptomatic impending atypical femoral fracture secondary to long-term bisphosphonate use. Prophylactic intramedullary nailing is indicated to relieve pain and prevent completion of the fracture, which is known for a high rate of delayed union or nonunion.

Question 33

When evaluating a patient with recurrent anterior shoulder instability, the 'glenoid track' concept is applied. A Hill-Sachs lesion is considered 'off-track' and at high risk for engagement if it:

Explanation

An 'off-track' Hill-Sachs lesion extends medial to the margin of the glenoid track. Because it is wider than the track provided by the glenoid, it will engage the anterior glenoid rim during abduction and external rotation, often necessitating a remplissage or Latarjet procedure.

Question 34

A 29-year-old male presents with a posterior hip dislocation following a dashboard injury in a motor vehicle collision. Following closed reduction, he exhibits a complete foot drop but normal plantar flexion. Which specific neural structure is most commonly injured in this scenario?

Explanation

The common peroneal division of the sciatic nerve is most vulnerable during a posterior hip dislocation. Its lateral location and tighter tethering at the sciatic notch make it more susceptible to stretch or compression from the posteriorly displaced femoral head.

Question 35

A 5-year-old child sustains a Gartland type III supracondylar humerus fracture. The hand is pink but lacks a palpable radial pulse. Following closed reduction and percutaneous pinning, the hand remains well-perfused (pink) with brisk capillary refill, but the radial pulse remains absent. What is the next best step in management?

Explanation

For a 'pink, pulseless' hand following stable reduction and pinning of a pediatric supracondylar humerus fracture, current guidelines recommend observation and close clinical monitoring. The collateral circulation around the elbow is typically sufficient to maintain viability.

Question 36

A 30-year-old male sustains a vertically oriented (Pauwels type III) femoral neck fracture. Which of the following internal fixation constructs provides the highest biomechanical stability against the high shear forces inherent to this specific fracture pattern?

Explanation

Pauwels type III (vertical) femoral neck fractures experience extremely high shear forces leading to varus collapse and nonunion. Biomechanical studies consistently show that a sliding hip screw combined with a derotational screw provides superior fixation and higher load-to-failure compared to multiple cancellous screws.

Question 37

A 55-year-old female undergoes open reduction and volar locked plating for a displaced distal radius fracture. Six weeks postoperatively, she suddenly loses the ability to actively extend her thumb interphalangeal joint. What is the most likely etiology of this complication?

Explanation

EPL tendon rupture is a well-known complication after distal radius fractures. In the setting of volar plating, it is typically caused by prominent dorsal screw tips penetrating the third extensor compartment, leading to attritional wear and sudden rupture.

Question 38

A 42-year-old sustains a severe, closed tibial pilon fracture with massive soft tissue swelling. Initial management consists of a spanning external fixator. What specific clinical sign dictates the safest appropriate timing for definitive open reduction and internal fixation?

Explanation

Definitive open fixation of a severe pilon fracture should be delayed until the soft tissue envelope has adequately recovered to minimize wound complications. The reappearance of skin wrinkles (the 'wrinkle sign') indicates the resolution of profound edema and readiness for surgical incision.

Question 39

A polytrauma patient with a severe bilateral pulmonary contusion and bilateral closed femoral shaft fractures presents in extremis with a serum lactate of 5.0 mmol/L. What is the primary physiologic rationale for performing temporary external fixation rather than immediate intramedullary nailing of the femurs?

Explanation

In critically ill polytrauma patients (borderline or in extremis), early definitive surgery such as intramedullary reaming and nailing acts as an inflammatory 'second hit'. This releases inflammatory mediators and marrow fat that can precipitate ARDS or multi-organ failure, a risk mitigated by damage control orthopedics (external fixation).

Question 40

A 42-year-old female presents with a medial tibial plateau fracture. Examination reveals tense leg compartments and pain with passive toe extension. What is the most appropriate sequence of surgical management?

Explanation

In the setting of a tibial plateau fracture with compartment syndrome, skeletal stabilization (temporary spanning external fixation or definitive ORIF) should be performed concurrently with a four-compartment fasciotomy. This prevents further soft tissue injury and protects the fasciotomy repairs.

Question 41

A 25-year-old male sustains a vertically oriented, displaced Pauwels type III femoral neck fracture. Biomechanically, which fixation construct provides the most stable construct to resist shear forces?

Explanation

Pauwels type III fractures have a high vertical angle, generating high shear forces. A fixed-angle device, such as a sliding hip screw (DHS) with an anti-rotation screw, is biomechanically superior to parallel screws in resisting these vertical shear forces.

Question 42

A polytrauma patient presents in hemorrhagic shock with an anteroposterior compression (APC) type III pelvic ring injury. A pelvic binder is to be applied. At what anatomic level should the binder be centered to optimally reduce the pelvic volume?

Explanation

Pelvic binders must be centered over the greater trochanters to effectively reduce the pelvic volume by closing the pubic symphysis. Placement over the iliac crests is incorrect and can paradoxically widen the pelvic floor.

Question 43

A 35-year-old construction worker sustains a Gustilo-Anderson type IIIB open tibia fracture. What is the recommended timeframe for achieving definitive soft-tissue coverage to minimize the risk of deep infection?

Explanation

Evidence demonstrates that achieving definitive soft-tissue coverage (e.g., free flap or rotational flap) within 5 to 7 days of injury significantly reduces the risk of deep infection. Coverage beyond this period is associated with substantially higher flap failure and infection rates.

Question 44

A 29-year-old male sustains a closed distal third spiral fracture of the humerus (Holstein-Lewis) with an intact radial nerve on initial presentation. Following closed reduction and splinting, he develops a complete radial nerve palsy. What is the most appropriate management?

Explanation

A secondary (post-reduction) radial nerve palsy in the setting of a Holstein-Lewis fracture is an absolute indication for immediate surgical exploration. The nerve is at high risk of becoming entrapped within the fracture site during the reduction maneuver.

Question 45

A 30-year-old male sustains a displaced talar neck fracture with subluxation of the subtalar joint, but the ankle joint remains congruous. According to the Hawkins classification, what type of fracture is this, and what is the approximate risk of avascular necrosis (AVN)?

Explanation

A Hawkins type II fracture is characterized by a talar neck fracture with subtalar joint subluxation or dislocation while the tibiotalar joint remains intact. The reported risk of avascular necrosis (AVN) for type II fractures is approximately 20-50%.

Question 46

A 50-year-old female driver presents after a high-speed motor vehicle collision with an isolated, displaced sternal fracture. Her initial ECG shows sinus tachycardia, and her vital signs are stable. Which of the following is the most appropriate next step in evaluating for blunt cardiac injury?

Explanation

In patients with blunt chest trauma and suspected blunt cardiac injury, screening with an admission 12-lead ECG and cardiac troponin is recommended. If both are normal, clinically significant blunt cardiac injury is effectively ruled out.

Question 47

A 40-year-old male sustains a high-energy closed tibial pilon fracture. The soft tissues are severely swollen with fracture blisters. What is the standard staged protocol to minimize soft-tissue complications?

Explanation

High-energy pilon fractures with severe soft-tissue compromise are best managed with a staged protocol. Initial spanning external fixation allows soft tissue recovery, followed by delayed definitive tibial ORIF once swelling subsides and the 'wrinkle sign' appears.

Question 48

What is the most common fracture associated with acute compartment syndrome in the pediatric population?

Explanation

Tibial shaft fractures are the most common cause of acute compartment syndrome in children, similar to adults. Although supracondylar humerus fractures are a classic cause of upper extremity compartment syndrome, tibial fractures hold the highest overall incidence.

Question 49

In a purely ligamentous Lisfranc injury, which of the following treatments has been shown in prospective randomized trials to yield superior functional outcomes and lower reoperation rates?

Explanation

Prospective randomized trials have demonstrated that primary arthrodesis of the medial column (1st-3rd TMT joints) for purely ligamentous Lisfranc injuries provides superior long-term functional outcomes compared to ORIF. ORIF has a higher rate of hardware failure and post-traumatic arthritis in purely ligamentous variants.

Question 50

A 35-year-old male presents with a Schatzker IV medial tibial plateau fracture following a high-energy motorcycle collision. Which of the following is true regarding this specific injury pattern compared to Schatzker II lateral plateau fractures?

Explanation

Schatzker IV (medial plateau) fractures typically result from high-energy varus and axial loading forces and are considered knee dislocation equivalents. Consequently, they carry a significantly higher rate of popliteal artery injury and compartment syndrome compared to lateral plateau fractures.

Question 51

During the ilioinguinal approach for an anterior column acetabular fracture, significant hemorrhage occurs while dissecting over the posterior aspect of the superior pubic ramus. This bleeding is most likely originating from an anastomosis between which two vascular systems?

Explanation

The corona mortis is a potentially life-threatening vascular anastomosis between the obturator (internal iliac system) and inferior epigastric (external iliac system) vessels. It is consistently located on the posterior aspect of the superior pubic ramus, averaging 4-6 cm from the symphysis pubis.

Question 52

A 25-year-old male sustains a high-energy distal femur fracture. CT imaging reveals a coronal plane fracture of the posterior aspect of the lateral femoral condyle (Hoffa fracture). What is the biomechanically optimal fixation strategy for this specific articular component?

Explanation

A Hoffa fracture is a coronal shear fracture of the posterior femoral condyle. Biomechanical studies demonstrate that anterior-to-posterior (AP) directed lag screws placed perpendicular to the fracture line provide superior fixation and stability compared to posterior-to-anterior screws.

Question 53

A 45-year-old smoker is undergoing ORIF of a displaced intra-articular calcaneus fracture via an extensile lateral approach. To minimize the risk of wound necrosis, the full-thickness flap is elevated subperiosteally. Which vascular structure serves as the primary blood supply to the apex of this flap?

Explanation

The extensile lateral approach relies on a full-thickness flap whose corner is critically supplied by the lateral calcaneal artery, a terminal branch of the peroneal artery. Subperiosteal elevation and avoiding forceful retraction are essential to prevent ischemic flap necrosis.

Question 54

A 6-year-old boy presents with a completely displaced, extension-type supracondylar humerus fracture. His hand is pink and warm, but the radial pulse is absent. After closed reduction and percutaneous pinning, the hand remains well-perfused with excellent capillary refill, but the radial pulse is still non-palpable. What is the next most appropriate step in management?

Explanation

In a 'pulseless, pink' hand following an adequate and stable reduction of a pediatric supracondylar humerus fracture, the standard of care is close clinical observation. Collateral circulation is sufficient to maintain viability, and the pulse typically returns within a few days to weeks.

Question 55

Six weeks following open reduction and internal fixation of a displaced talar neck fracture, an AP radiograph of the ankle demonstrates a distinct subchondral radiolucent band in the talar dome. What does this radiographic finding indicate?

Explanation

The Hawkins sign is a subchondral radiolucent band in the talar dome typically seen 6-8 weeks post-injury, indicating active subchondral bone resorption due to hyperemia. This is a highly reliable indicator of intact vascularity to the talar body, effectively ruling out avascular necrosis.

Question 56

A 55-year-old female is unable to extend her thumb interphalangeal joint 6 weeks after non-operative management of a minimally displaced distal radius fracture. Extensor indicis proprius (EIP) to extensor pollicis longus (EPL) transfer is planned. Where is the most reliable anatomical landmark to locate the proximal stump of the ruptured EPL tendon?

Explanation

The EPL tendon wraps directly around Lister's tubercle (occupying the third dorsal compartment), making it the most reliable anatomical landmark. Following spontaneous rupture in a distal radius fracture, the proximal stump typically retracts but is found just proximal to the retinaculum at this location.

Question 57

A 22-year-old male presents after a high-speed motor vehicle collision where he was wearing a lap belt. Radiographs and CT demonstrate a flexion-distraction injury (Chance fracture) extending through the L2 vertebral body. Which associated injury must be ruled out due to its high incidence in this scenario?

Explanation

Chance fractures (flexion-distraction injuries) commonly occur in lap-belt restrained passengers during severe decelerations. They are highly associated with intra-abdominal injuries (up to 50% incidence), particularly hollow viscus injuries like bowel perforations, necessitating urgent general surgery evaluation.

Question 58

When evaluating an acetabular fracture utilizing the standard Judet radiographic series, which structural components of the acetabulum are best visualized in profile on the obturator oblique view?

Explanation

The obturator oblique view of the pelvis profiles the anterior column and the posterior wall of the acetabulum. Conversely, the iliac oblique view profiles the posterior column and the anterior wall.

Question 59

A 30-year-old male sustains a vertically oriented (Pauwels Type III) femoral neck fracture. Biomechanically, which fixation construct provides the most stable construct against the high shear forces inherent to this specific fracture pattern?

Explanation

Pauwels Type III femoral neck fractures have a high vertical angle, subjecting the fracture to significant shear forces and a high risk of varus collapse. A fixed-angle device, such as a Dynamic Hip Screw (DHS), provides superior biomechanical resistance to these shear forces compared to parallel cancellous screws.

Question 60

A 38-year-old male presents with an ipsilateral midshaft clavicle fracture and a highly displaced scapular neck fracture (a 'floating shoulder'). According to current literature, which surgical approach is recommended to best restore the superior suspensory shoulder complex (SSSC)?

Explanation

In a true 'floating shoulder' characterized by significant displacement of both the clavicle and the scapular neck, fixation of both fractures is recommended. While isolated clavicle fixation was historically performed, it does not reliably correct severe scapular neck displacement or restore the SSSC.

Question 61

A 28-year-old rugby player undergoes ORIF of a pronation-external rotation (PER) ankle fracture. Intraoperatively, the syndesmosis remains unstable after fibular fixation and requires screw fixation. Which of the following variables is the most significant predictor of poor long-term functional outcome?

Explanation

Accurate anatomical reduction of the distal tibiofibular syndesmosis is the single most critical factor determining long-term functional outcomes in syndesmotic injuries. Malreduction alters tibiotalar contact stresses, leading to early onset of post-traumatic osteoarthritis.

Question 62

A 24-year-old male sustains a purely ligamentous Lisfranc injury and is considering surgical intervention. Compared to primary arthrodesis, which of the following statements accurately characterizes open reduction and internal fixation (ORIF) for this specific injury pattern?

Explanation

Prospective studies (such as Coetzee and Ly) have shown that purely ligamentous Lisfranc injuries treated with ORIF have a high rate of post-traumatic arthritis requiring secondary midfoot fusion. Primary arthrodesis is increasingly favored for purely ligamentous variants to improve long-term outcomes and limit secondary surgeries.

Question 63

In the underlying pathophysiology of acute compartment syndrome following a severe lower extremity crush injury, which physiological event occurs first as intracompartmental pressure begins to rise?

Explanation

As intracompartmental pressure rises, the thin-walled venous and lymphatic vessels are compressed first, resulting in venous outflow obstruction. This leads to vascular congestion, increased capillary hydrostatic pressure, and a vicious cycle of further tissue edema before eventual arterial occlusion.

Orthopedic Trauma MCQs & Clinical Insights: Advanced Exam Preparation

Orthopedic Board Prep MCQs: Fracture & Trauma | Part 44

Key Takeaway

Orthopedic Board Prep MCQs: Fracture & Trauma | Part 44

Chapter Index