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 10181
Topic: 2. Trauma
Which of the following describes a 'Die-punch' fracture component in the context of a distal radius fracture?
Correct Answer & Explanation
. An intra-articular depression of the lunate fossa.
Explanation
A 'Die-punch' fracture refers to an intra-articular depression fracture of the lunate fossa of the distal radius. This occurs when the lunate bone acts as a 'die' and impacts into the articular surface of the radius during the injury, creating a depressed fragment. This type of fracture often requires specific attention during reduction to restore articular congruence and prevent post-traumatic arthritis.
Question 10182
Topic: 2. Trauma
In the context of Colles fracture management, what is the 'ligamentotaxis' principle primarily applied for?
Correct Answer & Explanation
. To achieve indirect reduction and maintain length through tension on intact soft tissues.
Explanation
Ligamentotaxis is the principle of achieving indirect reduction and maintaining length and alignment of fracture fragments by applying tension to intact soft tissue ligaments, particularly the radiocarpal ligaments, often via external fixation with distraction. This pulls the fragments into a more anatomical position without direct manipulation. It is not for direct visualization or dynamic compression and aims for stability rather than micro-motion for healing.
Question 10183
Topic: 2. Trauma
What is the most common cause of nonunion in the distal radius following a Colles fracture?
Correct Answer & Explanation
. Distal radius nonunion is exceedingly rare.
Explanation
Nonunion of the distal radius is exceedingly rare due to its rich blood supply and cancellous bone composition. Distal radius fractures typically heal, though often with malunion (healing in an unacceptable position) rather than nonunion (failure to heal). While high-energy trauma, open fractures, and poor compliance can complicate healing, they are far more likely to result in malunion, infection, or other complications than a true nonunion of the distal radius itself.
Question 10184
Topic: 2. Trauma
Which type of immobilization is typically preferred immediately after closed reduction of an acutely swollen Colles fracture to allow for swelling accommodation?
Correct Answer & Explanation
. A sugar tong splint
Explanation
Immediately after closed reduction of an acutely swollen Colles fracture, a sugar tong splint is typically preferred. A sugar tong splint is non-circumferential and allows for swelling to occur without compressing the limb, thereby reducing the risk of compartment syndrome. Once the swelling has subsided (usually after 7-10 days), it can be converted to a short arm or long arm cast. A tight circular cast is contraindicated due to compartment syndrome risk. Removable braces or buddy taping are insufficient immobilization for an acute fracture. A dynamic external fixator is a surgical treatment.
Question 10185
Topic: 2. Trauma
Which of the following is an acceptable range for radial inclination on an AP radiograph after reduction of a Colles fracture?
Correct Answer & Explanation
. 15 degrees to 25 degrees
Explanation
Normal radial inclination (the angle formed by a line connecting the tips of the radial and ulnar styloids and a line perpendicular to the long axis of the radius) is typically around 22-23 degrees. Therefore, an acceptable range after reduction of a Colles fracture is generally considered to be 15 degrees to 25 degrees, aiming to restore it close to normal. Values below 15 degrees signify unacceptable loss of inclination.
Question 10186
Topic: 2. Trauma
Which type of fracture is typically confused with a Colles fracture but involves volar displacement and angulation of the distal fragment?
Correct Answer & Explanation
. Smith's fracture
Explanation
A Smith's fracture (also known as a reverse Colles fracture) is typically confused with a Colles fracture but involves volar displacement and angulation of the distal fragment, usually resulting from a fall onto the back of the hand or a fall onto an outstretched hand with the wrist in flexion. A Barton's fracture is an intra-articular fracture of the dorsal or volar rim of the distal radius with associated carpal subluxation. Chauffeur's fracture is a radial styloid fracture. Galeazzi and Monteggia are forearm shaft fractures with associated dislocations.
Question 10187
Topic: 2. Trauma
Which of the following factors is considered the strongest predictor for nonunion after tibia shaft fracture fixation?
Correct Answer & Explanation
. Open fracture (Gustilo-Anderson Type IIIB)
Explanation
While smoking, NSAID use, age, and comminution are all risk factors for nonunion, a Gustilo-Anderson Type IIIB open tibia fracture represents significant soft tissue compromise and periosteal stripping, leading to severe vascular damage and high-energy injury. This type of injury is well-documented as having the highest nonunion rates compared to other factors listed. The extensive soft tissue injury severely impairs the biological environment for healing. Smoking is a strong systemic risk factor, but local tissue damage of IIIB open fractures is often a more potent predictor.
Question 10188
Topic: 2. Trauma
A 28-year-old male sustains a severe crush injury to his foot. Initial examination reveals absent dorsalis pedis and posterior tibial pulses, significant swelling, and pallor of the toes. Sensation is diminished. What is the most appropriate immediate action?
Correct Answer & Explanation
. Emergent fasciotomy
Explanation
This patient presents with signs and symptoms highly concerning for acute compartment syndrome of the foot due to a crush injury, with evolving ischemia. Absent pulses and pallor suggest impending or established critical limb ischemia, necessitating immediate intervention. Delay in fasciotomy can lead to irreversible muscle necrosis and nerve damage. While vascular injury needs to be ruled out, the clinical picture strongly points towards compartment syndrome. Fasciotomy should be performed emergently. CT angiogram would delay definitive treatment. Ice and elevation are contraindicated in ischemia. Anticoagulants are not indicated and could worsen hematoma formation in a compartment syndrome.
Question 10189
Topic: 2. Trauma
Which of the following is the most important biomechanical consideration when planning intramedullary nailing for a comminuted subtrochanteric femur fracture?
Correct Answer & Explanation
. Controlling rotational stability and preventing shortening.
Explanation
For comminuted subtrochanteric femur fractures, controlling rotational stability and preventing shortening are paramount biomechanical considerations. The subtrochanteric region is subjected to high bending and rotational forces. Intramedullary nailing, particularly with reconstructive nails, provides excellent mechanical stability against these forces. While other options are important for all nailing, the unique anatomy and muscle pull in the subtrochanteric region make rotational and length stability particularly challenging and critical to achieve successful union and prevent malunion. Preservation of femoral head blood supply is more relevant for femoral neck fractures.
Question 10190
Topic: 2. Trauma
Which of the following best describes the principle of 'ligamentotaxis' in fracture management?
Correct Answer & Explanation
. Indirect reduction and maintenance of fracture fragments by tension across intact soft tissues (ligaments/capsule).
Explanation
Ligamentotaxis refers to the principle of indirect reduction and maintenance of fracture fragments by applying longitudinal distraction or tension across intact soft tissues, particularly ligaments and the joint capsule. This technique is commonly employed with external fixators, such as in distal radius fractures, pilon fractures, or calcaneal fractures, to indirectly reduce and hold fragments in place without direct manipulation, thereby minimizing soft tissue stripping. The other options describe direct fixation, general traction, biological healing, or joint-spanning fixation, respectively, but not the specific mechanism of indirect reduction via soft tissue tension.
Question 10191
Topic: 2. Trauma
A 30-year-old male sustains a closed, isolated spiral fracture of the middle third of the tibia. He is otherwise healthy. What is the most appropriate definitive management?
Correct Answer & Explanation
. Intramedullary nailing
Explanation
For isolated, closed, spiral (stable pattern) fractures of the tibial shaft in an otherwise healthy adult, intramedullary nailing is generally considered the gold standard for definitive management. It provides stable fixation, allows for earlier weight-bearing and functional recovery, and has high union rates. Casting can be used for very stable, undisplaced fractures but often leads to delayed union or malunion in spiral fractures. External fixation is usually reserved for open fractures or highly comminuted fractures with significant soft tissue injury. Plate fixation is an alternative but is associated with more soft tissue dissection and potentially higher infection rates compared to IM nailing. Percutaneous screw fixation is not suitable for a shaft fracture.
Question 10192
Topic: 2. Trauma
Which type of orthosis is most commonly used for the initial management of a mid-shaft clavicle fracture in an adult?
Correct Answer & Explanation
. Shoulder immobilizer
Explanation
For initial conservative management of a mid-shaft clavicle fracture, a simple shoulder immobilizer or sling is most commonly used. It provides comfort and support. A figure-of-eight brace has largely fallen out of favor as studies have shown it offers no benefit over a sling, can cause discomfort in the axilla, and may even displace fragments. A sling and swathe offers more immobilization than typically needed for clavicle fractures. Humeral fracture braces are for humerus fractures. A hard cervical collar is for the cervical spine.
Question 10193
Topic: 2. Trauma
Which of the following is considered a biomechanical advantage of unreamed intramedullary nailing over reamed nailing for acute tibia shaft fractures?
Correct Answer & Explanation
. Reduced risk of thermal necrosis of the endosteal blood supply.
Explanation
Unreamed intramedullary nailing has the primary biomechanical advantage of reducing the risk of thermal necrosis to the endosteal blood supply. Reaming removes the medullary contents, including blood vessels, which can temporarily compromise endosteal circulation, especially in highly comminuted or open fractures. Unreamed nails are typically smaller in diameter, preserving more endosteal blood flow. However, reamed nails allow for insertion of a larger diameter nail, leading to a stronger construct (bending and torsional stiffness). Neither method inherently facilitates interfragmentary compression without specific techniques. Earlier weight-bearing is often possible with both, but reamed nails generally provide superior mechanical stability. Operating time is not a primary biomechanical advantage.
Question 10194
Topic: 2. Trauma
A 16-year-old male sustains an open distal tibia and fibula fracture (Gustilo-Anderson Type IIIA). After irrigation, debridement, and initial stabilization with an external fixator, what is the most appropriate next step in his definitive management plan?
Correct Answer & Explanation
. Delayed primary wound closure and conversion to intramedullary nail within 3-7 days.
Explanation
For Gustilo-Anderson Type IIIA open tibia fractures, after initial irrigation, debridement, and external fixation, the most appropriate definitive management typically involves delayed primary wound closure and conversion to an intramedullary nail within 3-7 days, provided the soft tissue envelope allows. This approach balances the need for early fracture stabilization with soft tissue recovery and infection prevention. Immediate conversion is generally avoided in open fractures. Casting is insufficient for unstable open fractures. Serial debridements followed by skin grafting and then IMN is for more severe (Type IIIB/IIIC) or contaminated open fractures. Amputation is typically a last resort for limb-threatening injuries.
Question 10195
Topic: 2. Trauma
What is the primary concern when managing a Monteggia fracture-dislocation (ulnar shaft fracture with radial head dislocation)?
Correct Answer & Explanation
. Posterior interosseous nerve injury
Explanation
Monteggia fracture-dislocations (specifically Bado type I and II, involving an anterior or posterior radial head dislocation) are associated with a significant risk of posterior interosseous nerve (PIN) injury, which can lead to weakness in wrist and finger extension. This nerve is intimately related to the radial head and neck. While nonunion, malunion, and recurrent dislocation are potential complications, the nerve injury is a critical and specific association of this injury pattern, requiring careful assessment and often surgical exploration if deficits persist after reduction. Compartment syndrome is a general risk for all high-energy forearm trauma, but PIN injury is specific to Monteggia.
Question 10196
Topic: 2. Trauma
A 60-year-old male sustains a comminuted intertrochanteric hip fracture. He is medically fit. Which surgical implant offers the most stable fixation and allows for early mobilization?
Correct Answer & Explanation
. Cephalomedullary nail
Explanation
For a comminuted intertrochanteric hip fracture, especially in an elderly patient, a cephalomedullary nail (intramedullary hip screw) generally provides superior biomechanical stability and allows for earlier weight-bearing compared to a dynamic hip screw (DHS), particularly in unstable fracture patterns (e.g., reverse obliquity, subtrochanteric extension). Cannulated screws are typically for non-displaced femoral neck fractures. Hemiarthroplasty and total hip arthroplasty are typically reserved for femoral neck fractures, not intertrochanteric fractures, unless there's severe pre-existing osteoarthritis or nonunion.
Question 10197
Topic: 2. Trauma
What is the most common cause of acute compartment syndrome in the lower leg?
Correct Answer & Explanation
. Tibial shaft fracture
Explanation
Tibial shaft fractures are the most common cause of acute compartment syndrome in the lower leg. The high-energy trauma associated with these fractures, along with the anatomy of the leg compartments, predisposes to increased compartmental pressure. While direct crush injury and vascular injury can certainly cause compartment syndrome, tibial fractures are statistically the most frequent etiology. Exertional activity can causechronicexertional compartment syndrome, which is different from acute.
Question 10198
Topic: 2. Trauma
What is the most common complication of a calcaneal fracture?
Correct Answer & Explanation
. Subtalar arthritis
Explanation
Post-traumatic subtalar arthritis is the most common long-term complication of intra-articular calcaneal fractures, regardless of treatment method. The fracture often disrupts the articular surface of the subtalar joint, leading to incongruity and subsequent degenerative changes. While the other options can occur, subtalar arthritis significantly impacts long-term function and is the most prevalent. Compartment syndrome of the foot is an acute concern, not a long-term complication per se.
Question 10199
Topic: 2. Trauma
A patient sustains a posterior hip dislocation with an associated fracture of the femoral head. CT scan reveals that the fracture involves the portion of the femoral head inferior to the fovea capitis. According to the Pipkin classification, what type of fracture is this?
Correct Answer & Explanation
. Pipkin Type I
Explanation
The Pipkin classification describes femoral head fractures associated with posterior hip dislocations. Type I is a fracture of the femoral head inferior to the fovea capitis (non-weight-bearing portion). Type II is a fracture superior to the fovea capitis (weight-bearing portion). Type III is a Type I or II fracture associated with a femoral neck fracture. Type IV is a Type I or II fracture associated with an acetabular rim fracture.
Question 10200
Topic: Upper Extremity Trauma
A 25-year-old cyclist is struck by a vehicle and lands directly on the acromion of his shoulder. Radiographs reveal an acromioclavicular (AC) joint injury. The distal clavicle is displaced 200% superiorly relative to the acromion, and the coracoclavicular distance is more than double the contralateral side. According to the Rockwood classification, what type of injury is this?
Correct Answer & Explanation
. Type III
Explanation
The Rockwood classification of AC joint injuries is based on the direction and degree of clavicular displacement. Type III involves 25-100% superior displacement. Type V involves 100-300% superior displacement of the distal clavicle, accompanied by severe disruption of the deltotrapezial fascia. Type IV is posterior displacement into or through the trapezius. Type VI is inferior displacement (subcoracoid or subacromial).
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