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 1501
Topic: 2. Trauma
A 45-year-old female sustains an acetabular fracture in a high-speed motor vehicle collision. An obturator oblique radiograph demonstrates the pathognomonic "spur sign." This radiographic finding is diagnostic for which type of acetabular fracture?
Correct Answer & Explanation
. Both-column
Explanation
The "spur sign" seen on an obturator oblique view represents the intact portion of the ilium that remains attached to the axial skeleton while the acetabular articular surface is displaced medially. It is pathognomonic for a both-column acetabular fracture.
Question 1502
Topic: 2. Trauma
A 45-year-old male falls onto his shoulder. Radiographs demonstrate a proximal humerus fracture with the surgical neck displaced 1.5 cm and angulated 20 degrees. The greater tuberosity is fractured but displaced only 8 mm with no angulation. According to the Neer classification, how is this fracture categorized?
Correct Answer & Explanation
. Two-part
Explanation
The Neer classification defines a "part" only if the fragment is displaced > 1 cm or angulated > 45 degrees. Since the greater tuberosity is displaced only 8 mm, it is not considered a separate part; thus, this is a two-part surgical neck fracture.
Question 1503
Topic: 2. Trauma
A 48-year-old male sustains a transverse olecranon fracture after a fall onto a flexed elbow. The surgeon plans to perform a tension band wiring. Based on the biomechanical principles described in the case, what is the primary mechanism by which the tension band wiring construct stabilizes the fracture during elbow flexion?
Correct Answer & Explanation
. It converts distracting tensile forces on the dorsal aspect into compressive forces on the articular surface.
Explanation
Correct Answer: BThe case explicitly states, 'The tension band wiring construct converts these tensile forces into beneficial compressive forces across the fracture.' During elbow flexion, the triceps muscle exerts significant tensile (distracting) forces on the posterior aspect of the olecranon. The figure-of-eight wire, placed dorsally (on the tension side), pulls the K-wires together. This action, transmitted across the fracture, generates compression at the anterior articular surface (the compression side), thereby stabilizing the fracture dynamically. This dynamic compression is maximal during elbow flexion when the triceps pull is strongest, actively promoting fracture stability and healing.Option A is incorrectbecause while fixation provides stability, the primary mechanism of a tension band is not a buttress effect, which typically resists axial loading or shear. The tension band specifically addresses tensile forces.Option C is incorrectbecause the tension band is a load-sharing, dynamic construct, not a rigid plate designed to prevent all movement. Its strength lies in converting forces, allowing for controlled, early motion.Option D is incorrectbecause the K-wires provide axial alignment and anti-rotation, but the figure-of-eight wire is crucial for converting the tensile forces into compression, making it a combined load-sharing system.Option E is incorrectas a vacuum effect is not a biomechanical principle utilized in orthopedic fracture fixation.
Question 1504
Topic: 2. Trauma
A 78-year-old female presents with a displaced olecranon fracture following a low-energy fall. Radiographs and a CT scan reveal severe comminution of the proximal olecranon fragment with significant metaphyseal bone loss and severely osteoporotic bone. The surgeon is considering fixation options. Based on the case's discussion of contraindications for tension band wiring, which of the following is the most compelling reason to reconsider this technique for this patient?
Correct Answer & Explanation
. Severe comminution of the proximal fragment and severely osteoporotic bone.
Explanation
Correct Answer: CThe case explicitly lists 'Severe Comminution of the Proximal Fragment' (insufficient bone stock at the olecranon tip to adequately engage the K-wires) and 'Severely Osteoporotic Bone' (poor K-wire purchase can lead to early construct failure) as absolute contraindications for tension band wiring. In this patient, both factors are present, making tension band wiring highly unsuitable due to the high risk of construct failure.Option A (The patient's advanced age) is incorrectas age alone is not an absolute contraindication for tension band wiring if bone quality and fracture pattern are suitable. However, it often correlates with osteoporosis, which is the underlying issue.Option B (The risk of post-operative elbow stiffness) is incorrect. While elbow stiffness is a common complication of elbow trauma, tension band wiring is specifically chosen to allow early motion and minimize stiffness, not cause it.Option D (The potential for ulnar nerve irritation) is incorrect. While a known complication, it is not an absolute contraindication to the technique itself, but rather a risk to be managed during surgery.Option E (The need for early range of motion post-operatively) is incorrect. Early range of motion is an advantage and a goal of tension band wiring, not a reason to reconsider it.
Question 1505
Topic: 2. Trauma
During the definitive fixation phase of tension band wiring for an olecranon fracture, as depicted in the image, the surgeon is placing the two K-wires. According to the detailed surgical technique described, what is a critical requirement for the proper placement of these K-wires to ensure the effectiveness and stability of the tension band construct?
Correct Answer & Explanation
. The K-wires must engage the anterior cortex of the ulna.
Explanation
Correct Answer: CThe case states, 'Crucially, the K-wires must engage the anterior cortex of the ulna. Advance them until they just penetrate the anterior cortex.' This engagement of the anterior cortex provides a stable purchase point for the K-wires, allowing them to resist the tensile forces converted into compression by the figure-of-eight wire. Without adequate purchase in the anterior cortex, the K-wires can migrate or pull out, leading to construct failure.Option A is incorrect. The K-wires are inserted from the tip of the olecranon, parallel to each other, and across the fracture site into the distal ulnar shaft, not necessarily perpendicular to the long axis of the ulna. They are generally parallel to the ulnar shaft.Option B is incorrect. Engaging only the dorsal cortex would provide insufficient stability and would be prone to pullout, especially with the forces applied by the tension band.Option D is incorrect. The K-wires are bent 180 degrees into a small hookafterinsertion and cutting, not before, to prevent migration and provide a stable point for the tension band wire.Option E is incorrect. K-wires must be positioned to avoid the articular surface. Placing them through the articular surface would cause significant damage, leading to post-traumatic arthritis and impaired joint function.
Question 1506
Topic: 2. Trauma
A 32-year-old male undergoes tension band wiring for a simple transverse olecranon fracture. Six months post-operatively, he presents with localized pain and tenderness over the posterior aspect of his elbow, particularly when leaning on it or during certain movements. Radiographs confirm fracture union. Based on the case's discussion of complications, what is the most common complication following tension band wiring that aligns with this patient's symptoms?
Correct Answer: EThe case explicitly states that 'Hardware Prominence/Irritation' is the 'Most common complication' of tension band wiring, with an incidence of 30-80%. It typically manifests as discomfort from prominent K-wire ends or the overlying wire, especially when leaning on the elbow or during certain movements, and often requires elective hardware removal after fracture healing. The patient's symptoms of localized pain and tenderness over the posterior elbow, with confirmed union, are highly consistent with this complication.Option A (Nonunion of the fracture) is incorrectbecause the radiographs confirm fracture union, ruling out nonunion as the cause of symptoms.Option B (Deep infection requiring implant removal) is incorrect. While infection is a possible complication, it typically presents with signs of inflammation (redness, warmth, swelling, purulent discharge) and systemic symptoms, which are not described here. Its incidence is also much lower (1-5%).Option C (Ulnar nerve irritation/neuropathy) is incorrect. This would typically present with specific neurological symptoms such as numbness, tingling, or weakness in the small finger and ulnar half of the ring finger, or intrinsic hand muscle weakness, which are not mentioned.Option D (Post-traumatic arthritis of the elbow) is incorrect. While a long-term complication, it typically presents with diffuse joint pain, stiffness, and crepitus, often related to articular incongruity. The localized nature of the pain and tenderness points more towards hardware irritation.
Question 1507
Topic: 2. Trauma
A 55-year-old patient has undergone tension band wiring for a displaced olecranon fracture. In the immediate post-operative phase (first 1-2 weeks), the rehabilitation protocol emphasizes specific goals. Which of the following best describes the primary objective during this initial period?
Correct Answer & Explanation
. To protect the fixation, control pain and swelling, and initiate gentle, protected active and passive range of motion.
Explanation
Correct Answer: CThe case outlines the 'Immediate Post-Operative Phase' goals as: 'Protect fixation, control pain and swelling, initiate gentle motion.' It specifies that the splint may be removed for 'supervised, gentle active and passive range of motion (ROM) exercises' as soon as pain allows and wound healing permits (often within 3-7 days). This early, protected motion is crucial for preventing adhesions and maintaining cartilage health while protecting the healing fracture and fixation construct.Option A is incorrect. Full, unrestricted ROM against resistance is a goal for much later stages of rehabilitation, not the immediate post-operative phase, as it would risk fixation failure.Option B is incorrect. Heavy weight-bearing and closed-chain exercises are introduced in the progressive strengthening phase, much later in the rehabilitation process, after initial healing has occurred.Option D is incorrect. While initial immobilization in a splint is common for 1-2 weeks, the emphasis of tension band wiring is on early, protected mobilization to prevent stiffness, not prolonged complete immobilization.Option E is incorrect. Dynamic or static progressive splinting is typically considered for persistent ROM deficits in later stages, not as an immediate post-operative intervention, which would be too aggressive for early healing.
Question 1508
Topic: 2. Trauma
A 40-year-old construction worker sustains a displaced transverse olecranon fracture. He undergoes open reduction and internal fixation with tension band wiring. The image below illustrates the final construct. Based on the biomechanical principles of tension band wiring, what is the primary function of the figure-of-eight wire in this construct during active elbow flexion?
Correct Answer & Explanation
. To convert the tensile forces generated by the triceps muscle into compressive forces across the fracture site.
Explanation
Correct Answer: CThe case explicitly details the 'Tension Band Conversion' mechanism: 'As the triceps contracts and attempts to distract the fracture, the wire, being under tension, pulls the K-wires together. This pulling action, transmitted across the fracture, generates compression at the anterior articular surface (the compression side).' The figure-of-eight wire is the key component that converts the distracting tensile forces on the dorsal (tension) side of the olecranon into beneficial compressive forces on the articular (compression) side during elbow flexion, thereby stabilizing the fracture dynamically.Option A is incorrect. The bent ends of the K-wires, impacted into the bone, primarily prevent K-wire migration, not the figure-of-eight wire itself.Option B is incorrect. While the overall construct contributes to stability, the K-wires, especially if slightly divergent, primarily provide axial alignment and anti-rotation. The figure-of-eight wire's main role is force conversion.Option D is incorrect. The tension band is a dynamic system. It doesn't act as a static buttress; rather, it actively generates compression in response to tensile loads.Option E is incorrect. The figure-of-eight wire is for fixation, not for bone graft placement.
Question 1509
Topic: 2. Trauma
Consider the tension band wiring construct shown in the image, used for an olecranon fracture. In the context of this specific fixation method, what is the primary role of the two parallel K-wires within the overall construct?
Correct Answer & Explanation
. To provide stable axial alignment and anti-rotation for the fracture fragments.
Explanation
Correct Answer: CThe case states, 'The K-wires provide stable axial alignment and anti-rotation.' While the figure-of-eight wire is responsible for converting tensile forces into compression, the K-wires are essential for maintaining the anatomical reduction, preventing shear, and resisting rotational forces across the fracture site. They act as the 'anchors' through which the tension band wire exerts its compressive effect.Option A is incorrect. The primary compressive force is generated by the figure-of-eight wire converting tensile forces, not directly by the K-wires themselves.Option B is incorrect. While the K-wires do provide points for the figure-of-eight wire to loop around, their primary role is not simply to prevent the wire from slipping, but to provide structural stability to the bone fragments.Option D is incorrect. K-wires are metallic implants for fixation, not scaffolds for bone growth. Bone healing occurs through biological processes at the fracture site.Option E is incorrect. In tension band wiring, the K-wires are a definitive part of the fixation, not merely temporary. If a plate is needed, it would typically be the primary fixation or an adjunct, not a subsequent replacement for K-wires in a tension band construct.
Question 1510
Topic: 2. Trauma
A 68-year-old male presents to the emergency department after a fall, complaining of severe elbow pain and inability to extend his arm. Initial AP and lateral radiographs show a comminuted olecranon fracture with significant articular involvement. To accurately assess the fracture morphology, articular congruity, and bone stock for pre-operative planning, which of the following imaging modalities is most highly recommended?
Correct Answer & Explanation
. Computed Tomography (CT) scan
Explanation
Correct Answer: DThe case states, 'Computed Tomography (CT) Scan: Highly recommended for comminuted fractures, articular involvement, or suspected coronoid fractures. A CT provides detailed information regarding fragment orientation, articular congruity, and bone stock, which is invaluable for pre-operative templating and surgical strategy.' Given the comminuted nature and articular involvement, a CT scan is the superior imaging modality for detailed surgical planning.Option A (Magnetic Resonance Imaging - MRI) is incorrect. While MRI provides excellent soft tissue detail, it is generally not the primary imaging modality for acute fracture assessment, especially for bony detail and articular congruity, where CT excels. It might be used for ligamentous injuries or cartilage assessment, but not as the first-line for complex bony architecture.Option B (Ultrasound of the elbow) is incorrect. Ultrasound is useful for soft tissue structures (tendons, ligaments, effusions) but has very limited utility in assessing complex bony fractures and articular surfaces.Option C (Bone scintigraphy - bone scan) is incorrect. A bone scan is used to detect metabolic activity in bone, such as stress fractures, infections, or tumors, but it does not provide the anatomical detail required for pre-operative planning of a comminuted articular fracture.Option E (Stress radiographs of the elbow) is incorrect. Stress radiographs are used to assess ligamentous stability, not the detailed morphology of a comminuted articular fracture.
Question 1511
Topic: 2. Trauma
An 85-year-old frail patient with severe osteoporosis sustains a displaced olecranon fracture. The surgeon is evaluating the suitability of tension band wiring for this patient. Based on the case's discussion of contraindications, which of the following is a significant concern that might preclude the use of tension band wiring in this specific patient?
Correct Answer & Explanation
. Poor K-wire purchase in severely osteoporotic bone, leading to early construct failure.
Explanation
Correct Answer: CThe case explicitly lists 'Severely Osteoporotic Bone' as an absolute contraindication for tension band wiring, stating that 'Poor K-wire purchase can lead to early construct failure.' In an 85-year-old frail patient with severe osteoporosis, the bone quality would likely be insufficient to provide stable purchase for the K-wires, making the tension band construct prone to failure.Option A (The patient's low functional demand) is incorrect. Low functional demand might influence the choice between operative and non-operative management or the type of fixation (e.g., fragment excision in very low-demand elderly), but it is not a contraindication to tension band wiring itself if the bone quality is adequate.Option B (The risk of post-operative elbow stiffness) is incorrect. Tension band wiring is designed to allow early motion and minimize stiffness, so this is not a contraindication to the technique.Option D (The potential for ulnar nerve irritation) is incorrect. While a known complication, it is a risk to be managed during surgery, not an absolute contraindication to the technique itself.Option E (The need for early mobilization post-operatively) is incorrect. Early mobilization is an advantage and a goal of tension band wiring, not a reason to avoid it.
Question 1512
Topic: Lower Extremity Trauma
During surgical exploration of a high-energy syndesmotic injury in the 32-year-old athlete, the surgeon notes significant disruption of the anterior aspect of the distal tibiofibular joint. Which of the following ligaments is typically the weakest and most commonly the first to fail during an external rotation injury, originating from the Chaput tubercle?
Correct Answer & Explanation
. Anterior Inferior Tibiofibular Ligament (AITFL)
Explanation
Correct Answer: DThe case explicitly states under 'Ligamentous Anatomy' that the 'Anterior Inferior Tibiofibular Ligament (AITFL)... originates from the Chaput tubercle of the tibia and inserts onto the Wagstaffe tubercle of the fibula. It courses obliquely in a distal and lateral direction. The AITFL is the weakest of the syndesmotic ligaments and is typically the first to fail during an external rotation injury.'Incorrect Options:A) Posterior Inferior Tibiofibular Ligament (PITFL):The PITFL is described as 'a robust structure' and 'significantly stronger than the AITFL,' providing resistance to posterior translation. It originates from the Volkmann tubercle.B) Transverse Tibiofibular Ligament (TTFL):The TTFL is considered the deep, inferior component of the PITFL and acts as a labrum. It is not typically the first to fail.C) Interosseous Tibiofibular Ligament (ITFL):The ITFL is the distal continuation of the interosseous membrane, consisting of short, dense fibers, and acts as a primary stabilizer against lateral translation. It is not the weakest or first to fail in external rotation.E) Deltoid Ligament:The deltoid ligament is a medial ankle ligament, not part of the syndesmotic complex, though it is often injured concomitantly with syndesmotic injuries.
Question 1513
Topic: 2. Trauma
A 32-year-old male presents with a high-energy ankle injury. Standard radiographs are obtained. Based on the provided image (representing a typical ankle radiograph) and the clinical scenario, which of the following radiographic findings, if present, would most strongly indicate the need for operative stabilization of the syndesmosis?
Correct Answer & Explanation
. A medial clear space of 5 mm on the mortise view.
Explanation
Correct Answer: DUnder 'Operative Indications,' the case clearly states: 'Radiographic parameters dictating operative intervention include a medial clear space greater than 4 millimeters, a tibiofibular clear space greater than 5 millimeters, or a tibiofibular overlap of less than 1 millimeter on the mortise view.' A medial clear space of 5 mm on the mortise view unequivocally exceeds the 4 mm threshold, indicating frank instability requiring surgical stabilization.Incorrect Options:A) A medial clear space of 3 mm on the mortise view:This is within the normal range (typically <4 mm) and would not indicate instability.B) A tibiofibular clear space of 4 mm on the AP view:This is within the normal range (typically <5 mm) and would not indicate instability.C) A tibiofibular overlap of 2 mm on the mortise view:This is within the normal range (typically >1 mm) and would not indicate instability.E) An isolated fibular fracture without medial injury:While a fibular fracture can be associated with syndesmotic injury, an 'isolated' fracture without medial injury or other signs of instability (like widening of clear spaces) would not, by itself, be a definitive indication for syndesmotic fixation. Intraoperative assessment would still be crucial.
Question 1514
Topic: Lower Extremity Trauma
A 32-year-old athlete undergoes surgical stabilization of a high-energy syndesmotic injury with trans-syndesmotic screws. During the early mobilization phase (Weeks 2-6), which of the following is the most appropriate weight-bearing recommendation for this patient?
Correct Answer & Explanation
. Strict non-weight-bearing (NWB) or touch-down weight-bearing (TDWB) in a CAM boot.
Explanation
Correct Answer: CUnder 'Phase 2 Early Mobilization (Weeks 2-6),' the case specifies: 'For screw fixation, patients generally remain NWB or touch-down weight-bearing (TDWB) to protect the hardware.' This is crucial to prevent screw breakage, which is a common complication with rigid fixation.Incorrect Options:A) Full weight-bearing (FWB) in a CAM boot:This is generally too aggressive for screw fixation during this early phase and is more aligned with suture button constructs.B) Progressive weight-bearing as tolerated without a boot:This is too aggressive and lacks the necessary protection for the healing syndesmosis and hardware.D) Partial weight-bearing (PWB) with crutches, no boot:While PWB is a step, the absence of a protective boot is inappropriate for this phase of syndesmotic injury recovery.E) Full weight-bearing (FWB) in a short leg cast:While a cast provides immobilization, FWB is too early for screw fixation, and a CAM boot allows for controlled range of motion, which is initiated in this phase.
Question 1515
Topic: 2. Trauma
A 55-year-old male with well-controlled HIV (CD4 400 cells/ยตL, undetectable viral load) is undergoing a total hip arthroplasty for severe avascular necrosis of the femoral head. During acetabular preparation, the surgeon notes that the bone quality is softer than anticipated, consistent with preoperative DEXA findings of osteopenia. To ensure optimal long-term stability of the acetabular component, which intraoperative strategy is most appropriate?
Correct Answer & Explanation
. Utilize adjunctive screw fixation through pre-drilled holes in the acetabular cup, directing screws away from neurovascular structures.
Explanation
Correct Answer: CThe case mentions under 'HIV-Specific Intraoperative Considerations' that 'Be prepared for potentially osteopenic or osteoporotic bone. For cementless components, ensure optimal reaming and broaching to achieve maximal primary press-fit. Consider augmented fixation (e.g., screws, cages) or use of cemented stems if bone quality is severely compromised. Use meticulous technique to prevent intraoperative fractures.' Utilizing adjunctive screw fixation provides additional primary stability for a press-fit cup, which is crucial in osteopenic bone where initial press-fit might be suboptimal for long-term ingrowth.Option A is incorrect. Using a smaller reamer than templated would result in an undersized component, leading to poor fit and stability. Reaming should expose bleeding subchondral bone for optimal ingrowth, but not necessarily be smaller.Option B is incorrect. Relying solely on press-fit in osteopenic bone increases the risk of early loosening and failure, as bone ingrowth may be compromised or delayed.Option D is incorrect. While cemented components can be an option for severely compromised bone, the question implies a press-fit cup is being considered. If a press-fit cup is chosen, adjunctive screws are a common strategy to augment fixation in osteopenic bone, rather than an immediate switch to cement unless the bone is extremely poor.Option E is incorrect. Increasing reaming depth significantly risks perforating the acetabulum or removing too much bone, further compromising bone stock and potentially leading to pelvic discontinuity or neurovascular injury.
Question 1516
Topic: 2. Trauma
What is the most frequently reported complication following tension band wiring of an isolated, closed, transverse olecranon fracture?
Correct Answer & Explanation
. Symptomatic hardware requiring removal
Explanation
Symptomatic hardware is the most common complication of tension band wiring for olecranon fractures, reported in up to 40-80% of cases. The prominent nature of the proximal K-wires and wire knot directly beneath the subcutaneous tissues of the posterior elbow often necessitates elective hardware removal.
Question 1517
Topic: 2. Trauma
An 82-year-old low-demand female sustains a severely comminuted olecranon fracture. The surgeon elects to perform a fragment excision and triceps advancement. To maintain elbow stability and prevent anterior subluxation of the ulna, what is the maximum percentage of the proximal olecranon articular surface that can be safely excised?
Correct Answer & Explanation
. 50%
Explanation
Biomechanically, up to 50% of the proximal olecranon can be excised without causing elbow instability, provided that the collateral ligaments and the anterior bundle of the medial collateral ligament (which inserts on the sublime tubercle) remain intact.
Question 1518
Topic: 2. Trauma
What is the most common complication following tension band wiring of a transverse olecranon fracture?
Correct Answer & Explanation
. Symptomatic hardware requiring removal
Explanation
Symptomatic hardware is the most frequent complication of tension band wiring for olecranon fractures, often necessitating secondary surgical removal. Nonunion and infection rates are relatively low.
Question 1519
Topic: 2. Trauma
A 35-year-old male is scheduled for open reduction and internal fixation of a transverse olecranon fracture. The surgeon opts for tension band wiring. For this biomechanical construct to effectively convert tensile forces into compressive forces at the articular surface, which of the following must be intact or adequately reconstructed?
Correct Answer & Explanation
. The anterior cortex of the ulna
Explanation
Tension band wiring relies on an intact opposite (anterior) cortex to act as a fulcrum. If the anterior cortex is comminuted or absent, the tension band will fail to convert posterior tensile forces into articular compression, leading to collapse.
Question 1520
Topic: Lower Extremity Trauma
When evaluating an ankle mortise radiograph for suspected syndesmotic injury, which of the following measurements is the most reliable radiographic indicator of syndesmotic widening?
Correct Answer & Explanation
. Tibiofibular clear space greater than 5 mm measured 1 cm above the plafond
Explanation
A tibiofibular clear space of greater than 5 to 6 mm measured 1 cm proximal to the tibial plafond on both AP and mortise views is considered abnormal and indicates syndesmotic diastasis. Tibiofibular overlap is dependent on rotation and is less reliable.
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