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 10881
Topic: 2. Trauma
A 55-year-old male sustains a high-energy Schatzker VI tibial plateau fracture. Which characteristic of this fracture pattern most significantly increases the risk of developing acute compartment syndrome?
Correct Answer & Explanation
. Medial plateau comminution
Explanation
Metaphyseal-diaphyseal dissociation (Schatzker VI) involves significant energy transfer and severe soft tissue disruption, greatly increasing the risk of acute compartment syndrome compared to simple split or depressed plateau fractures.
Question 10882
Topic: 2. Trauma
A 25-year-old male sustains a low-velocity civilian gunshot wound to the thigh, resulting in a non-comminuted, midshaft femur fracture. The neurovascular exam is intact. What is the most appropriate management?
Correct Answer & Explanation
. Formal wide excision of the bullet tract followed by external fixation
Explanation
Low-velocity gunshot wounds to the femur without massive soft tissue destruction can be safely managed with local wound care, tetanus/antibiotic prophylaxis, and immediate intramedullary nailing. Formal wide debridement of the tract is unnecessary.
Question 10883
Topic: 2. Trauma
A patient with a severe open tibia fracture (Gustilo-Anderson IIIB) undergoes serial debridement. According to Godina's classic principles, free tissue transfer is associated with the lowest failure and infection rates when performed within what timeframe?
Correct Answer & Explanation
. 72 hours
Explanation
Godina demonstrated that free flap coverage of severe extremity injuries performed within 72 hours of injury results in significantly lower flap failure and deep infection rates compared to delayed coverage.
Question 10884
Topic: 2. Trauma
A trauma patient undergoes pelvic radiography. The obturator oblique view of the Judet series reveals a pathognomonic 'spur sign'. This radiographic finding is specifically associated with which of the following acetabular fracture patterns?
Correct Answer & Explanation
. T-type fracture
Explanation
The 'spur sign' is pathognomonic for a both-column acetabular fracture. It represents the remaining intact portion of the ilium attached to the axial skeleton, which projects posteriorly on the obturator oblique radiograph.
Question 10885
Topic: Pelvic & Acetabular Trauma
A 38-year-old male sustains a severe pelvic crush injury. He develops a large, fluctuant swelling over the greater trochanter. Aspiration yields serosanguinous fluid. What is the most appropriate definitive management of this Morel-Lavallée lesion to minimize infection prior to pelvic fixation?
Correct Answer & Explanation
. Open debridement and delayed closure
Explanation
A Morel-Lavallée lesion is a closed degloving injury that traps necrotic fat and hematoma, posing a high risk for subsequent surgical site infection. Formal open debridement (or extensive percutaneous debridement) with delayed closure is the safest approach before internal fixation.
Question 10886
Topic: 2. Trauma
A 50-year-old male presents with an enlarging, painful anterior leg mass 15 years after a conservatively managed tibia fracture with a history of missed compartment syndrome. Imaging shows a fusiform mass with peripheral calcification. Biopsy shows necrotic muscle. What is the best management?
Correct Answer & Explanation
. Marginal excision of the mass
Explanation
The patient has calcific myonecrosis, a rare late complication of compartment syndrome. Because surgical excision frequently results in chronic non-healing wounds and secondary infection, observation and symptomatic treatment are highly recommended.
Question 10887
Topic: 2. Trauma
In a hypotensive trauma patient with severe pelvic hemorrhage unresponsive to initial massive transfusion and pelvic binding, Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is planned. In which aortic zone should the balloon be inflated to best control pelvic hemorrhage?
Correct Answer & Explanation
. Zone 1
Explanation
For isolated, life-threatening pelvic hemorrhage, the REBOA balloon should be deployed in Zone 3 (from the lowest renal artery down to the aortic bifurcation). Zone 1 is used for suspected intra-abdominal bleeding, and Zone 2 is a non-deployment evasion zone.
Question 10888
Topic: 2. Trauma
A 35-year-old male is brought to the emergency department after a high-speed motorcycle collision. He is hypotensive with a systolic blood pressure of 75 mmHg. Primary survey reveals an anteroposterior compression type III (APC-III) pelvic ring injury. A pelvic binder is applied, but his hemodynamics do not improve. A FAST exam is negative for intraperitoneal fluid. What is the most appropriate next step in management according to ATLS algorithms?
In a hemodynamically unstable patient with a severe pelvic ring fracture, initial stabilization includes a pelvic binder. If the patient remains unstable and intra-abdominal hemorrhage has been ruled out (negative FAST or DPL), the primary source of bleeding is assumed to be the retroperitoneal pelvic space (venous plexus or arterial injury). The appropriate next step is pre-peritoneal pelvic packing and/or pelvic angiography with embolization. Ex-fix application is secondary to initial volume and packing/angio protocols in the persistently hypotensive patient.
Question 10889
Topic: 2. Trauma
A 32-year-old male sustains a proximal third tibia fracture. He develops severe leg pain out of proportion and diminished two-point discrimination on the plantar aspect of his foot. Intracompartmental pressure testing indicates an isolated acute compartment syndrome of the deep posterior compartment. Which of the following anatomic structures are located within this specific compartment?
Correct Answer & Explanation
. Tibialis anterior and deep peroneal nerve
Explanation
The deep posterior compartment of the leg contains the tibialis posterior, flexor digitorum longus, flexor hallucis longus, the posterior tibial artery and vein, and the tibial nerve. Compression here leads to ischemia of the tibial nerve, causing sensory deficits on the plantar aspect of the foot. The anterior compartment contains the deep peroneal nerve and anterior tibial artery. The lateral compartment contains the superficial peroneal nerve.
Question 10890
Topic: 2. Trauma
A 42-year-old man is struck by a motor vehicle and sustains a closed, displaced transverse acetabular fracture. Examination reveals a large, fluctuant area over the greater trochanter and lateral thigh. Aspiration of the collection yields serosanguinous fluid with fat droplets. What is the most appropriate management of this soft tissue lesion in the context of planned surgical fracture fixation?
Correct Answer & Explanation
. Formal incision, debridement, and dead-space management prior to or during definitive fixation
Explanation
The patient has a Morel-Lavallée lesion, a closed internal degloving injury where subcutaneous tissue is sheared off the underlying fascia, creating a cavity filled with blood, lymph, and necrotic fat. If large and situated in the surgical field for a planned fracture fixation (e.g., Kocher-Langenbeck approach), it carries a very high risk of infection. Standard management is formal incision, extensive debridement of necrotic tissue, and dead-space management.
Question 10891
Topic: 2. Trauma
A 35-year-old male sustains a vertical, shear-type (Pauwels Type III) femoral neck fracture. Biomechanically, what is the most stable fixation strategy to resist vertical shear forces while preserving the native hip?
Correct Answer & Explanation
. Sliding hip screw (SHS) with an anti-rotation screw
Explanation
Pauwels Type III fractures (>50 degrees to horizontal) experience high vertical shear forces. Biomechanical studies have shown that a fixed-angle device, such as a sliding hip screw (SHS), combined with an anti-rotation screw provides superior resistance to vertical shear and a higher load to failure compared to multiple parallel cancellous screws in young adults with high-angle femoral neck fractures.
Question 10892
Topic: 2. Trauma
According to the delta pressure criteria for diagnosing acute compartment syndrome, emergency fasciotomy is universally indicated when the difference between the patient's diastolic blood pressure and the measured compartment pressure falls below what threshold?
Correct Answer & Explanation
. 10 mmHg
Explanation
The delta pressure is calculated as Diastolic Blood Pressure (DBP) minus the intracompartmental pressure. A delta pressure of less than 30 mmHg indicates inadequate perfusion to the tissue capillary beds and is the universally accepted threshold indicating the need for emergent fasciotomy.
Question 10893
Topic: 2. Trauma
According to the Schatzker classification system for tibial plateau fractures, a fracture pattern involving the lateral tibial plateau that is uniquely associated with metaphyseal-diaphyseal dissociation (where the entire condyle or condyles separate from the shaft) is classified as:
Correct Answer & Explanation
. Type II
Explanation
A Schatzker Type VI fracture is defined by metaphyseal-diaphyseal dissociation. It can involve either one or both condyles separating completely from the diaphyseal shaft, representing a high-energy injury pattern often associated with severe soft tissue compromise and a higher risk of compartment syndrome. Type V is bicondylar but without the complete transverse separation of metaphysis from diaphysis.
Question 10894
Topic: 2. Trauma
A 45-year-old male is brought to the ED after a motorcycle accident. He has a systolic blood pressure of 75 mmHg. Radiographs show an anteroposterior compression type III (APC-III) pelvic fracture. A pelvic binder is applied, and 2 liters of crystalloid and 2 units of packed RBCs are given. His BP improves to 85 mmHg but remains tenuous. FAST exam is negative. What is the most appropriate next step in management?
Correct Answer & Explanation
. Pelvic angiography with embolization or preperitoneal pelvic packing
Explanation
In a hemodynamically unstable patient with a mechanically unstable pelvic ring injury (like APC-III), initial management includes mechanical stabilization (binder) and resuscitation. If the patient remains unstable and intra-abdominal bleeding is ruled out (negative FAST), the bleeding is presumed to be retroperitoneal from the pelvic fracture. The next most appropriate step is pelvic angiography with embolization or preperitoneal pelvic packing.
Question 10895
Topic: Upper Extremity Trauma
Recent anatomic studies have challenged historical teachings regarding the vascularity of the proximal humerus. Based on current evidence, which of the following arteries provides the predominant blood supply to the humeral head?
Correct Answer & Explanation
. Ascending branch of the anterior humeral circumflex artery
Explanation
Historically, the arcuate artery (the ascending branch of the anterior humeral circumflex artery) was thought to be the primary blood supply to the humeral head. However, modern quantitative anatomic studies (e.g., Brooks et al., and Hettrich et al.) have demonstrated that the posterior humeral circumflex artery provides the vast majority (approximately 64%) of the blood supply to the humeral head.
Question 10896
Topic: 2. Trauma
A 35-year-old male falls from a height and sustains a femoral neck fracture. The fracture line makes an angle of 65 degrees with the horizontal on the anteroposterior radiograph. According to the Pauwels classification, what is the main biomechanical consequence of this vertical fracture pattern compared to a more horizontal fracture?
Correct Answer & Explanation
. Increased shear forces across the fracture site leading to high rates of nonunion and varus collapse
Explanation
The Pauwels classification for femoral neck fractures is based on the angle the fracture line makes with the horizontal. Type I is <30 degrees, Type II is 30-50 degrees, and Type III is >50 degrees. Higher angles (more vertical fractures) experience immensely increased shear forces rather than compressive forces, predisposing them to a high rate of nonunion, fixation failure, and varus collapse.
Question 10897
Topic: 2. Trauma
A 28-year-old male sustains a vertically oriented (Pauwels type III) femoral neck fracture. Biomechanical studies have shown that in comparison to three parallel cancellous screws, fixation with a sliding hip screw (fixed-angle device) with a derotational screw offers which primary mechanical advantage?
Correct Answer & Explanation
. Increased resistance to vertical shear forces
Explanation
Pauwels type III fractures are high-angle, vertically oriented femoral neck fractures commonly seen in young adults after high-energy trauma. They are highly unstable and subject to significant vertical shear forces during weight-bearing. A sliding hip screw (SHS), combined with a derotational screw, provides a mechanically superior construct by converting shear forces into compressive forces, whereas multiple cancellous screws are more prone to failure (varus collapse) under shear stress.
Question 10898
Topic: 2. Trauma
A 40-year-old male sustains a closed, spiral fracture of the distal third of the humeral shaft (Holstein-Lewis fracture). On initial examination in the emergency department, his radial nerve function is fully intact. A closed reduction and coaptation splinting are performed. Following reduction, the patient presents with an inability to extend his wrist or fingers. What is the most appropriate management regarding the radial nerve?
Correct Answer & Explanation
. Observation and an EMG at 3 weeks
Explanation
While primary radial nerve palsies present at the time of injury in closed humeral shaft fractures are typically observed, a secondary radial nerve palsy that developsafterclosed reduction is an absolute indication for immediate surgical exploration. The nerve is at high risk of being entrapped or lacerated within the fracture fragments (particularly in Holstein-Lewis fractures where the nerve is tethered by the lateral intermuscular septum).
Question 10899
Topic: 2. Trauma
A 28-year-old male sustains a vertically oriented Pauwels type III femoral neck fracture after a high-energy fall. Which of the following fixation constructs provides the highest biomechanical stability to counteract shear forces for this specific fracture pattern?
Correct Answer & Explanation
. Dynamic hip screw (DHS) with an anti-rotation screw
Explanation
For vertically oriented femoral neck fractures in young adults (Pauwels III), shear forces are extremely high. A fixed-angle device such as a Dynamic Hip Screw (DHS) with a derotation screw provides superior biomechanical stability compared to multiple cancellous screws, reducing the risk of varus collapse and nonunion. In young adults, head preservation is preferred over arthroplasty.
Question 10900
Topic: Pelvic & Acetabular Trauma
A 45-year-old male is brought to the Emergency Department after a crush injury. He has an anteroposterior compression (APC-III) pelvic ring injury and is hemodynamically unstable. A pelvic binder is applied. Where must the pelvic binder be centered for maximal biomechanical effectiveness?
Correct Answer & Explanation
. Over the greater trochanters
Explanation
A pelvic binder must be applied centered over the greater trochanters to effectively close the pelvic volume and stabilize the pelvic ring in open book (APC) injuries. Application over the iliac crests or abdomen does not provide the appropriate vectors to close the ring, can paradoxically widen the pelvis, and can limit abdominal access.
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