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 2501
Topic: 2. Trauma
A 28-year-old male sustains a highly vertical, displaced femoral neck fracture (Pauwels Type III) after a fall from a height. Open reduction and internal fixation is planned. Which fixation construct provides the highest biomechanical stability against shear forces for this specific fracture pattern?
Correct Answer & Explanation
. A sliding hip screw (fixed-angle device) supplemented with a derotation screw
Explanation
Pauwels Type III fractures possess a high degree of verticality, subjecting them to intense shear forces. Biomechanical studies indicate that a fixed-angle device, such as a sliding hip screw with a derotation screw, offers superior resistance to shear compared to multiple cancellous screws.
Question 2502
Topic: 2. Trauma
A 42-year-old female presents with a posteromedial shear fracture of the tibial plateau (Schatzker IV variant). Which surgical approach provides the most direct visualization and allows for optimal anti-glide buttress plating of this specific fragment?
Correct Answer & Explanation
. Posteromedial approach utilizing the interval between the medial gastrocnemius and pes anserinus
Explanation
The posteromedial approach, exploiting the interval between the pes anserinus anteriorly and the medial head of the gastrocnemius posteriorly, grants direct access to the posterior aspect of the medial tibial plateau. This is critical for applying a posterior buttress plate to counteract vertical shear forces.
Question 2503
Topic: 2. Trauma
A 30-year-old male is admitted with a closed, severely comminuted tibial shaft fracture. Two hours later, he complains of excruciating leg pain that is unresponsive to IV opioids. Examination reveals exquisite pain with passive stretch of the hallux. What absolute threshold of delta pressure (Diastolic Blood Pressure minus Intracompartmental Pressure) definitively mandates a four-compartment fasciotomy?
Correct Answer & Explanation
. Delta pressure less than 30 mmHg
Explanation
A delta pressure (Diastolic Blood Pressure minus Intracompartmental Pressure) of less than 30 mmHg is a highly sensitive and specific objective threshold indicating acute compartment syndrome. When clinical suspicion is high and delta pressure falls below 30 mmHg, emergent fasciotomy is mandated.
Question 2504
Topic: 2. Trauma
A 35-year-old farm worker sustains a severely contaminated open tibial shaft fracture with a 12 cm laceration and significant periosteal stripping, requiring a rotational flap for coverage. According to the Gustilo-Anderson classification, what is the most appropriate initial antibiotic regimen?
Correct Answer & Explanation
. First-generation cephalosporin, an aminoglycoside, and penicillin
Explanation
This is a Gustilo-Anderson Type IIIB open fracture occurring in a farm environment, significantly increasing the risk of Clostridium infection. Standard protocol requires a first-generation cephalosporin, an aminoglycoside, and high-dose penicillin for anaerobic coverage.
Question 2505
Topic: Pelvic & Acetabular Trauma
A patient presents after a severe crush injury with an anteroposterior compression (APC) Type III pelvic ring injury. What primary anatomical structure's complete disruption differentiates an APC III from an APC II injury?
Correct Answer & Explanation
. Posterior sacroiliac ligaments
Explanation
In the Young-Burgess classification, APC II involves disruption of the anterior sacroiliac, sacrotuberous, and sacrospinous ligaments but leaves the posterior sacroiliac ligaments intact. APC III involves complete disruption of the posterior sacroiliac ligaments, resulting in complete global pelvic instability.
Question 2506
Topic: 2. Trauma
When fixing a displaced 4-part proximal humerus fracture, preservation of the humeral head blood supply is critical. Based on recent quantitative perfusion studies, which artery provides the primary blood supply to the articular segment of the humeral head?
Correct Answer & Explanation
. Posterior humeral circumflex artery via intraosseous anastomoses
Explanation
Historically, the anterior humeral circumflex was thought to be the primary vascular supply. However, recent anatomic studies demonstrate that the posterior humeral circumflex artery provides the vast majority (up to 64%) of the blood supply to the humeral head.
Question 2507
Topic: 2. Trauma
In the pathophysiology of acute compartment syndrome following a tibia fracture, which physiological sequence correctly describes the initial cascade leading to muscle ischemia?
Compartment syndrome begins with elevated interstitial pressure that exceeds venous outflow pressure, leading to venous hypertension. This reduces the arteriovenous pressure gradient, which collapses capillaries and impairs local tissue perfusion long before actual arterial occlusion occurs.
Question 2508
Topic: 2. Trauma
A 25-year-old male sustains a vertically oriented (Pauwels Type III) basicervical femoral neck fracture. Which biomechanical factor makes this fracture pattern particularly prone to failure of internal fixation?
Correct Answer & Explanation
. High shear forces across the fracture site
Explanation
Pauwels Type III fractures possess a highly vertical fracture line (angle > 50 degrees). This vertical orientation converts normal weight-bearing forces into high shear forces across the fracture site, significantly increasing the risk of varus collapse and nonunion.
Question 2509
Topic: 2. Trauma
A 60-year-old obese male sustains a high-energy knee injury, resulting in a Schatzker Type VI tibial plateau fracture. He has multiple open wounds and significant soft tissue swelling. What is the most appropriate initial surgical approach for this injury?
Correct Answer & Explanation
. External fixation with provisional joint spanning, followed by delayed definitive fixation.
Explanation
Correct Answer: BSchatzker Type VI tibial plateau fractures are complex, high-energy injuries often associated with severe soft tissue damage, swelling, and open wounds. Immediate definitive ORIF carries a high risk of wound complications, infection, and flap necrosis due to the compromised soft tissue envelope. The preferred initial management is often damage control orthopedics: emergent external fixation with provisional joint spanning (spanning ex-fix) to stabilize the fracture, protect the soft tissues, and allow swelling to subside. Definitive ORIF is then performed in a delayed fashion (typically 7-14 days) once the 'wrinkle sign' appears and the soft tissues are amenable to surgery. Closed reduction and casting are inadequate for displaced, unstable, or articular fractures. Arthroplasty is not an acute treatment for fractures. Arthroscopic assistance is primarily for less severe fractures.
Question 2510
Topic: 2. Trauma
A 32-year-old male involved in a motorcycle accident sustains multiple long bone fractures (bilateral femoral and tibial shaft fractures). Three days post-injury, he develops acute respiratory distress, petechial rash on his chest and axilla, and altered mental status. What is the most likely diagnosis?
Correct Answer & Explanation
. Fat embolism syndrome (FES)
Explanation
Correct Answer: CThe classic triad of respiratory distress, neurological dysfunction (altered mental status), and petechial rash appearing 12-72 hours after long bone fractures is highly suggestive of Fat Embolism Syndrome (FES). While pulmonary embolism and ARDS are serious complications, the presence of the petechial rash and the specific timing post-multiple long bone fractures strongly point to FES. Pneumonia and cerebral infarct are less likely given the specific constellation of symptoms and the acute post-traumatic timeline. FES is a life-threatening complication, with management being primarily supportive.
Question 2511
Topic: 2. Trauma
Which location of an osteochondroma carries a higher risk for neurological complications due to compression?
Correct Answer & Explanation
. Vertebral body
Explanation
Correct Answer: DOsteochondromas occurring in the vertebral body or near neural foramina, although rare, have a significantly higher risk of causing neurological complications due to compression of the spinal cord or nerve roots. Other common locations like the distal femur, proximal tibia, proximal humerus, or ribs are less likely to cause neurological deficits unless very large or atypically located. The question asks for 'neurological complications', making the vertebral body the prime suspect.
Question 2512
Topic: 2. Trauma
A 29-year-old female horse rider presents to the emergency department after falling off her horse, sustaining an isolated closed injury to her left foot. Initial radiographs are obtained:
Based on these initial findings, what is the most appropriate immediate next step in the management of this patient?
Correct Answer & Explanation
. C. Order a CT scan of the foot to better delineate the fracture pattern and assess for associated injuries.
Explanation
Correct Answer: CExplanation:The initial radiographs (Figure 8.16) clearly show a displaced, comminuted fracture of the body of the navicular bone with overlap of mid-tarsal bones. While the diagnosis of a navicular fracture is evident, the complex anatomy of the midfoot and the comminuted nature of this intra-articular fracture necessitate further detailed imaging for definitive surgical planning. A CT scan is the gold standard for evaluating complex foot fractures, especially those involving the tarsal bones, as it provides superior detail regarding fracture lines, comminution, articular involvement, and displacement in multiple planes (coronal, sagittal, axial). This information is critical for determining the optimal surgical approach, fixation strategy, and prognosis.A. Proceed directly to open reduction and internal fixation (ORIF) given the clear displacement:While operative intervention is likely, proceeding directly to surgery without a CT scan is premature and could lead to inadequate planning and suboptimal outcomes. The CT scan is essential for understanding the 3D anatomy of the fracture.B. Apply a short leg cast and discharge with instructions for non-weight bearing:This is an unstable, displaced intra-articular fracture. Non-operative management is generally not favored for such injuries due to the high risk of malunion, post-traumatic arthritis, and loss of foot function. Furthermore, a CT scan is still needed to confirm the extent of injury before deciding on definitive management.D. Perform an immediate MRI to evaluate for ligamentous injuries and soft tissue compromise:While MRI is excellent for soft tissue and ligamentous injuries, it is not the primary imaging modality for detailed bony architecture in acute, complex fractures like this. A CT scan is more crucial for surgical planning of the bone injury itself. MRI might be considered later if there are specific concerns about ligamentous instability not addressed by CT.E. Initiate broad-spectrum intravenous antibiotics due to the high-energy mechanism:The case states this is an isolated closed injury. There is no indication of an open fracture or infection, so prophylactic antibiotics are not warranted at this stage.
Question 2513
Topic: 2. Trauma
Following the initial assessment, a CT scan of the foot is obtained, confirming a displaced, comminuted, unstable intra-articular fracture of the navicular body:
Based on the case discussion, which of the following is the MOST critical factor influencing the decision to favor operative intervention over non-operative management for this specific injury?
Correct Answer & Explanation
. C. The intra-articular nature and displacement of the fracture fragments.
Explanation
Correct Answer: CExplanation:The case explicitly states, 'It is an unstable displaced intra-articular fracture and I would favour operative intervention rather than non-operative. The principles of management are to restore the articular surface, stabilize and hold the fracture to allow early mobilization.' The most critical factor driving the decision for operative management in navicular body fractures is the involvement of the articular surface and the degree of displacement and comminution. Intra-articular fractures, especially when displaced, disrupt the joint congruity, leading to high rates of post-traumatic osteoarthritis, pain, and functional impairment if not anatomically reduced and stabilized.A. The patient's young age and active lifestyle as a horse rider:While these are factors that support aggressive treatment to restore function, they are not the primarypathologicalreason for choosing surgery. The nature of the fracture itself is the main driver.B. The presence of significant soft tissue swelling around the midfoot:Soft tissue swelling is common in high-energy foot injuries and can delay surgery, but it is not an indication for surgery itself. It's a factor to manage pre-operatively.D. The isolated nature of the injury without other associated fractures:An isolated injury might simplify surgical planning, but it doesn't inherently mandate surgery. The characteristics of the navicular fracture are what dictate the need for operative intervention.E. The potential for compartment syndrome if not surgically stabilized:While compartment syndrome is a serious complication to monitor for, surgical stabilization of the fracture itself is not the primary treatment for compartment syndrome. Fasciotomy is. Furthermore, the potential for compartment syndrome is a risk of the injury, not the primary reason for choosing operative fixation of the navicular fracture.
Question 2514
Topic: 2. Trauma
A 29-year-old female horse rider undergoes operative fixation for a displaced, comminuted intra-articular navicular body fracture. Despite successful anatomical reduction and stable fixation, she develops persistent midfoot pain and stiffness several years post-surgery. Which of the following late complications is most commonly associated with this type of injury, even after optimal surgical management?
Correct Answer & Explanation
. C. Post-traumatic osteoarthritis of the talonavicular joint.
Explanation
Correct Answer: CExplanation:The case lists 'Late complications include non-union and loss of medial longitudinal arch support, painful talonavicular joint, post-traumatic osteoarthritis, as well as avascular necrosis and collapse.' Among these, post-traumatic osteoarthritis (OA) is a very common and often debilitating long-term complication of intra-articular fractures, especially in weight-bearing joints like the talonavicular joint. Even with anatomical reduction, damage to the articular cartilage at the time of injury, subtle incongruities, or altered biomechanics can lead to progressive degenerative changes and pain.A. Chronic regional pain syndrome (CRPS):CRPS is a potential complication of any extremity trauma or surgery, but it is not themost commonlyassociated late complication specifically with intra-articular navicular fractures after successful fixation.B. Recurrent compartment syndrome:Compartment syndrome is an immediate or early complication, not a late complication that recurs years after successful fixation.D. Stress fracture of an adjacent metatarsal:While possible, a stress fracture of an adjacent metatarsal is not a direct or most common late complication of a navicular body fracture itself.E. Deep vein thrombosis (DVT):DVT is an early complication related to immobility and surgery, not a late complication occurring years post-operatively.
Question 2515
Topic: 2. Trauma
The candidate discusses the immediate management of the patient's high-energy foot injury prior to definitive surgical planning. Which of the following is the most critical immediate management step for this type of injury, as mentioned in the case?
Correct Answer & Explanation
. C. Close monitoring for evolving compartment syndrome.
Explanation
Correct Answer: CExplanation:The case states, 'I would initially treat the injured foot in a backslab, with strict elevation and intermittent cryotherapy, adequate analgesia and close monitoring for evolving compartment syndrome.' For high-energy foot injuries, compartment syndrome is a critical and potentially devastating complication. Early recognition and monitoring are paramount to prevent irreversible tissue damage. Therefore, close monitoring for compartment syndrome is the most critical immediate management step.A. Immediate weight-bearing mobilization to prevent stiffness:This is contraindicated for an unstable, displaced fracture. Non-weight bearing and immobilization are necessary.B. Administration of prophylactic antibiotics to prevent infection:The case specifies an 'isolated closed injury.' There is no indication for prophylactic antibiotics in a closed fracture unless there are specific risk factors for infection (e.g., immunocompromised patient, severe contamination if open).D. Urgent reduction of the fracture in the emergency department:While reduction might be considered, especially if there is significant deformity or neurovascular compromise, the primary immediate concern for a high-energy foot injury is compartment syndrome. A formal reduction is often performed in the operating room after definitive imaging and planning.E. Application of a rigid plaster cast for definitive immobilization:A backslab (splint) is preferred initially over a rigid cast to allow for swelling and to facilitate compartment syndrome monitoring. A rigid cast could contribute to compartment syndrome if swelling occurs.
Question 2516
Topic: 2. Trauma
Reviewing the initial radiographs of the 29-year-old female horse rider's left foot:
What is the most accurate description of the injury based solely on these images and the initial case presentation?
Correct Answer & Explanation
. B. Displaced, comminuted intra-articular fracture of the navicular body with mid-tarsal overlap.
Explanation
Correct Answer: BExplanation:The case description and the candidate's initial assessment explicitly state: 'The radiographs of the left foot, AP and oblique show a displaced fracture of the body of navicular bone with comminution. There is overlap of mid-tarsal bones...' The provided radiographs (Figure 8.16) visually confirm these findings, showing multiple fragments and disruption of the navicular's normal contour and articulation, consistent with a displaced, comminuted intra-articular fracture of the navicular body. The 'overlap of mid-tarsal bones' suggests involvement of the surrounding joints, making it an intra-articular injury.A. Isolated non-displaced navicular tuberosity fracture with no mid-tarsal involvement:The images clearly show a fracture involving the main body of the navicular, not just the tuberosity, and it is displaced and comminuted, not non-displaced. There is also mid-tarsal overlap.C. Stress fracture of the navicular with associated cuneiform subluxation:A stress fracture typically appears as a subtle cortical break or sclerosis, not a grossly displaced and comminuted fracture as seen here. While cuneiform subluxation might be present, the primary injury is a high-energy fracture.D. Avulsion fracture of the navicular with significant talonavicular dislocation:An avulsion fracture is typically a small fragment pulled off by a ligament or tendon. This is a much larger, comminuted fracture of the bone body. While there is disruption, 'significant talonavicular dislocation' is not the primary description given.E. Isolated cuboid fracture with secondary navicular impaction:The primary fracture is clearly of the navicular bone, not the cuboid. While impaction might occur, the main injury is the navicular fracture.
Question 2517
Topic: 2. Trauma
The candidate outlines the principles of operative management for the navicular fracture: 'to restore the articular surface, stabilize and hold the fracture to allow early mobilization.' Which of the following is NOT a primary goal for operative intervention in this specific navicular body fracture, as implied by the case discussion?
Correct Answer & Explanation
. D. Facilitate immediate full weight-bearing post-operatively.
Explanation
Correct Answer: DExplanation:The case emphasizes 'to restore the articular surface, stabilize and hold the fracture to allow early mobilization.' While early mobilization is a goal, 'early mobilization' does not equate to 'immediate full weight-bearing.' For a comminuted intra-articular fracture of a weight-bearing bone like the navicular, immediate full weight-bearing would jeopardize the fixation and the healing process. Non-weight bearing or protected weight-bearing is typically required for several weeks to months post-operatively.A. Achieve anatomical reduction of the articular surface:This is a stated primary principle: 'restore the articular surface.'B. Provide stable fixation to allow for early range of motion:This is a stated primary principle: 'stabilize and hold the fracture to allow early mobilization.'C. Prevent avascular necrosis of the navicular bone:The case extensively discusses the vulnerability of the navicular's blood supply and the risk of AVN. While surgery itself can sometimes compromise blood supply, a well-planned surgery aims to preserve it and stabilize the fracture to promote healing, thereby preventing AVN and non-union.E. Minimize the risk of post-traumatic osteoarthritis:By restoring the articular surface and achieving stable fixation, the primary goal is to maintain joint congruity and function, which directly aims to minimize the long-term risk of post-traumatic osteoarthritis.
Question 2518
Topic: Pelvic & Acetabular Trauma
A 42-year-old female is brought in after a rollover MVC. She is hemodynamically unstable. A pelvic radiograph shows a widened pubic symphysis of 4 cm and disrupted posterior sacroiliac ligaments. Where is the most anatomically correct placement for a pelvic circumferential compression device?
Correct Answer & Explanation
. Level of the greater trochanters
Explanation
Pelvic binders should be placed at the level of the greater trochanters to effectively reduce pelvic volume by applying appropriate compressive forces across the pelvic ring. Placement higher on the iliac crests can cause paradoxical opening or inadequate reduction.
Question 2519
Topic: 2. Trauma
A 24-year-old male sustains a subtrochanteric femur fracture. During closed reduction for intramedullary nailing, the proximal fragment is noted to be flexed, abducted, and externally rotated. Which muscle group is primarily responsible for the flexion deformity of the proximal fragment?
Correct Answer & Explanation
. Iliopsoas
Explanation
In subtrochanteric femur fractures, the proximal fragment is characteristically deformed into flexion by the iliopsoas, abduction by the gluteus medius and minimus, and external rotation by the short external rotators.
Question 2520
Topic: 2. Trauma
A 29-year-old male undergoes reamed intramedullary nailing of a closed tibial shaft fracture. Postoperatively, he requires increasing doses of opioids and complains of severe pain with passive toe stretch. His diastolic blood pressure is 70 mmHg. What intracompartmental pressure reading strongly supports the diagnosis of acute compartment syndrome?
Correct Answer & Explanation
. Delta pressure of 25 mmHg
Explanation
Acute compartment syndrome is diagnosed when the delta pressure (diastolic blood pressure minus the intracompartmental pressure) is less than 30 mmHg. A delta pressure of 25 mmHg indicates critical tissue ischemia requiring urgent fasciotomy.
Test Yourself
Switch to an interactive, timed exam simulation to truly master this topic.