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2. Trauma MCQs

Practice Set 389 of 640

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 7761

Topic: 2. Trauma

A 28-year-old man falls onto his lateral shoulder and sustains a closed midshaft clavicle fracture. Which of the following is considered an indication for operative fixation to prevent nonunion and symptomatic malunion?

. Nondisplaced fracture in a dominant arm
. Fracture with 5 mm of shortening
. Fracture with 100% displacement and 2.5 cm of shortening
. Fracture with a single butterfly fragment with minimal displacement
. Skin tenting without blanching

Correct Answer & Explanation

. Nondisplaced fracture in a dominant arm

Explanation

Operative indications for midshaft clavicle fractures include 100% displacement, shortening greater than 2 cm, z-type comminution, and impending skin breakdown. These factors are strongly associated with higher rates of nonunion.

Question 7762

Topic: 2. Trauma

A 65-year-old female undergoes open reduction and internal fixation of a 3-part proximal humerus fracture. Six weeks postoperatively, radiographs show varus collapse of the humeral head and superior screw cutout. Which of the following intraoperative factors most likely contributed to this complication?

. Inadequate superior screw placement
. Failure to restore medial calcar support
. Over-reduction of the head fragment into valgus
. Use of locking rather than non-locking screws
. Excessive release of the rotator interval

Correct Answer & Explanation

. Inadequate superior screw placement

Explanation

Failure to restore the medial column (calcar) support in proximal humerus fractures is the most significant biomechanical risk factor for postoperative varus collapse and subsequent screw cutout.

Question 7763

Topic: Upper Extremity Trauma

A 30-year-old male cyclist falls directly on his shoulder. Radiographs reveal a Type V acromioclavicular (AC) joint injury. Which of the following accurately describes the pathologic anatomy of this injury pattern?

. Sprain of the AC ligaments with intact coracoclavicular (CC) ligaments
. Complete disruption of the AC and CC ligaments with <25% superior displacement
. Complete disruption of AC and CC ligaments with >100% superior displacement
. Complete disruption of AC and CC ligaments with posterior displacement into the trapezius
. Inferior displacement of the clavicle under the coracoid process

Correct Answer & Explanation

. Sprain of the AC ligaments with intact coracoclavicular (CC) ligaments

Explanation

A Type V AC joint injury involves complete disruption of both the AC and CC ligaments along with the deltotrapezial fascia, resulting in >100% (and up to 300%) superior displacement of the clavicle relative to the acromion.

Question 7764

Topic: 2. Trauma

Which of the following is the most significant combination of risk factors for nonunion in a midshaft clavicle fracture treated nonoperatively?

. Complete displacement and shortening > 2 cm
. Patient age over 65 and non-smoking status
. Concomitant rib fractures and proximal third location
. Undisplaced butterfly fragment and male sex
. Oblique fracture pattern and shortening < 1 cm

Correct Answer & Explanation

. Complete displacement and shortening > 2 cm

Explanation

Complete displacement (especially lacking cortical contact) and significant shortening (>2 cm) are the most significant risk factors for nonunion and poor functional outcomes in nonoperatively managed midshaft clavicle fractures.

Question 7765

Topic: 2. Trauma

According to the Neer classification for proximal humerus fractures, what defines a "part" as being displaced?

. >5 mm displacement or >20 degrees angulation
. >1 cm displacement or >45 degrees angulation
. >2 cm displacement or >30 degrees angulation
. >1.5 cm displacement or >45 degrees angulation
. Any cortical discontinuity

Correct Answer & Explanation

. >5 mm displacement or >20 degrees angulation

Explanation

The Neer classification defines a displaced segment (or "part") as having greater than 1 cm of displacement or greater than 45 degrees of angulation. Fractures that do not meet these criteria are considered 1-part fractures regardless of the number of fracture lines.

Question 7766

Topic: 2. Trauma

A 65-year-old woman undergoes open reduction and internal fixation (ORIF) with a locked plate for a 3-part proximal humerus fracture. One year postoperatively, she complains of severe, grinding shoulder pain. Radiographs demonstrate intra-articular screw penetration. What was the most likely intraoperative technical error?

. Placing screws too short
. Failure to recognize varus collapse leading to superior screw cutout
. Placing the plate too distally on the shaft
. Over-tightening the rotator interval
. Stripping of the axillary nerve

Correct Answer & Explanation

. Placing screws too short

Explanation

Intra-articular screw penetration is the most common complication of locked plating for proximal humerus fractures. It frequently results from postoperative varus collapse of the humeral head, which drives the fixed-angle screws through the articular surface.

Question 7767

Topic: 2. Trauma

A 21-year-old cyclist falls directly onto his shoulder. Radiographs show a midshaft clavicle fracture. Which of the following is considered an absolute indication for operative fixation?

. 1.5 cm of shortening
. 100% displacement without skin tenting
. Open fracture
. Comminution with a butterfly fragment
. Female gender to improve cosmetic outcome

Correct Answer & Explanation

. 1.5 cm of shortening

Explanation

Absolute indications for operative fixation of a clavicle fracture include open fractures, neurovascular compromise, and severe skin tenting with impending compromise. Shortening and displacement are relative indications.

Question 7768

Topic: 2. Trauma

A 40-year-old male sustains a distal third clavicle fracture. Radiographs confirm a Neer Type II fracture with superior displacement of the medial fragment.

What is the most appropriate management and primary rationale?

. Conservative management; low risk of nonunion
. Open reduction internal fixation; high risk of nonunion
. Distal clavicle excision; to prevent acromioclavicular arthritis
. Figure-of-eight brace; to compress the fracture fragments
. Coracoclavicular ligament reconstruction alone; to address instability

Correct Answer & Explanation

. Conservative management; low risk of nonunion

Explanation

Neer Type II distal clavicle fractures involve detachment of the coracoclavicular ligaments from the medial fragment, leading to significant instability and a high nonunion rate (up to 30%) with conservative management, making ORIF the standard of care.

Question 7769

Topic: 2. Trauma

A 70-year-old female presents 1 year after an anatomic total shoulder arthroplasty performed for a complex proximal humerus fracture. She is unable to actively elevate her arm above 60 degrees. Radiographs show superior migration of the humeral head and resorption of the greater tuberosity. What is the primary cause of her functional deficit?

. Axillary nerve palsy
. Subscapularis failure
. Greater tuberosity nonunion/failure
. Deltoid dehiscence
. Glenoid component loosening

Correct Answer & Explanation

. Axillary nerve palsy

Explanation

Greater tuberosity nonunion or resorption is a major complication of anatomic shoulder arthroplasty for fracture. It results in loss of posterosuperior rotator cuff function, leading to superior head migration and pseudoparalysis.

Question 7770

Topic: 2. Trauma

Which of the following clinical scenarios represents an absolute indication for immediate operative fixation of an acute midshaft clavicle fracture?

. Complete displacement with 1.5 cm of shortening
. A severely comminuted fracture pattern
. An open fracture
. A Z-deformity in an elite overhead athlete
. Skin tenting without vascular compromise

Correct Answer & Explanation

. Complete displacement with 1.5 cm of shortening

Explanation

While complete displacement, shortening, and athletic status may be relative indications for ORIF of the clavicle, an open fracture is an absolute indication for surgical management. Other absolute indications include polytrauma requiring early weight-bearing through the upper extremities and progressive neurologic deficit.

Question 7771

Topic: 2. Trauma

A 65-year-old male undergoes open reduction and internal fixation (ORIF) with a locking plate for a 3-part proximal humerus fracture. Six weeks postoperatively, radiographs demonstrate intra-articular screw penetration. What is the most common technical error during the index procedure leading to this complication?

. Placement of the plate too inferiorly
. Failure to restore medial calcar support
. Use of excessively long screws initially
. Inadequate fixation of the greater tuberosity
. Placement of screws in the subchondral bone

Correct Answer & Explanation

. Placement of the plate too inferiorly

Explanation

Intra-articular screw penetration after proximal humerus locking plate fixation is most commonly a secondary complication due to varus collapse of the humeral head. This collapse is almost exclusively caused by a failure to reconstruct or support the medial calcar during the initial reduction.

Question 7772

Topic: 2. Trauma

A 40-year-old male sustains a high-energy trauma resulting in a severely displaced scapular fracture. Which of the following parameters is a widely accepted indication for operative fixation of a scapular neck/body fracture?

. Glenoid articular step-off greater than 4 mm
. Scapular body medialization of 5 mm
. Scapular neck angulation of 15 degrees
. Coracoid process displacement of 3 mm
. Acromial fracture without displacement

Correct Answer & Explanation

. Glenoid articular step-off greater than 4 mm

Explanation

Operative indications for scapula fractures include significant intra-articular glenoid displacement (step-off > 4-5 mm), profound medialization of the glenohumeral joint (usually >20 mm), or severe angular deformity (>40 degrees). Minor angulation and small displacements are reliably treated non-operatively.

Question 7773

Topic: 2. Trauma

Which of the following radiographic findings is the most reliable predictor of subsequent humeral head ischemia (avascular necrosis) following a severe proximal humerus fracture?

. Greater tuberosity displacement greater than 10 mm
. Metaphyseal diaphyseal translation greater than 50%
. Medial calcar metaphyseal segment length less than 8 mm
. Disruption of the lateral periosteum
. Angulation of the surgical neck greater than 45 degrees

Correct Answer & Explanation

. Greater tuberosity displacement greater than 10 mm

Explanation

A medial calcar hinge disruption and a short metaphyseal head extension (less than 8 mm) are the most reliable predictors of humeral head ischemia. This reflects disruption of the primary blood supply from the ascending branch of the anterior humeral circumflex artery and capsular vessels.

Question 7774

Topic: 2. Trauma

What is the most frequent hardware-related complication following open reduction and internal fixation of a proximal humerus fracture using a locking plate?

. Plate breakage
. Infection
. Nonunion
. Intra-articular screw penetration
. Subacromial impingement

Correct Answer & Explanation

. Plate breakage

Explanation

Intra-articular screw penetration (primary or secondary to screw cut-out from varus collapse) is the most common hardware-related complication of locked plating for proximal humerus fractures, occurring in up to 10-20% of cases.

Question 7775

Topic: 2. Trauma

A 55-year-old woman sustains a proximal humerus fracture. According to Hertel's criteria, which radiographic factor is the most reliable predictor of subsequent humeral head ischemia?

. Metaphyseal head extension < 8 mm
. Greater tuberosity displacement > 10 mm
. Intact medial hinge
. Fracture extending into the surgical neck
. Disruption of the anterior circumflex humeral artery

Correct Answer & Explanation

. Metaphyseal head extension < 8 mm

Explanation

Hertel described predictors of humeral head ischemia, which include a short calcar segment (metaphyseal head extension < 8 mm), disruption of the medial hinge, and a basicervical (anatomic neck) fracture pattern.

Question 7776

Topic: 2. Trauma

When performing open reduction and internal fixation of a surgical neck proximal humerus fracture with a locking plate, what is the primary biomechanical advantage of placing inferior medial calcar screws?

. Prevents superior pullout of the plate
. Prevents varus collapse of the humeral head
. Prevents excessive valgus angulation
. Reduces the risk of avascular necrosis
. Increases rotational mobility of the fracture site

Correct Answer & Explanation

. Prevents superior pullout of the plate

Explanation

Placing screws in the inferior medial quadrant of the humeral head (calcar screws) provides crucial structural support, preventing varus collapse and subsequent superior screw cutout through the articular surface.

Question 7777

Topic: 2. Trauma

What is the most common complication following open reduction and internal fixation of a proximal humerus fracture using a fixed-angle locking plate?

. Avascular necrosis of the humeral head
. Deep surgical site infection
. Intra-articular screw penetration
. Fracture nonunion
. Permanent axillary nerve palsy

Correct Answer & Explanation

. Avascular necrosis of the humeral head

Explanation

Intra-articular screw penetration is the most common complication of locking plate fixation for proximal humerus fractures, often resulting from post-operative varus collapse or primary over-penetration.

Question 7778

Topic: 2. Trauma

A 65-year-old woman sustains a displaced proximal humerus fracture after a fall.

According to the Hertel criteria, which of the following radiographic findings is most predictive of developing avascular necrosis of the humeral head?

. Greater tuberosity displacement > 5 mm
. Surgical neck translation > 50%
. Calcar length of less than 8 mm attached to the articular segment
. Angulation of the articular segment > 30 degrees
. Involvement of the lesser tuberosity

Correct Answer & Explanation

. Greater tuberosity displacement > 5 mm

Explanation

Hertel et al. identified criteria predictive of humeral head ischemia, including a short metaphyseal head extension (calcar length < 8 mm), a disrupted medial hinge, and an anatomic neck fracture pattern. These factors indicate severe disruption of the arcuate branch of the anterior humeral circumflex artery and posterior intraosseous vessels.

Question 7779

Topic: 2. Trauma

A 50-year-old woman undergoes ORIF with a locking plate for a 3-part proximal humerus fracture.

Six weeks postoperatively, she reports a grinding sensation and mechanical block during elevation. Radiographs show varus settling of the humeral head. What is the most common hardware-related complication necessitating reoperation in this scenario?

. Plate breakage at the surgical neck
. Intra-articular screw penetration
. Screw back-out from the humeral diaphysis
. Subacromial impingement from the proximal edge of the plate
. Symptomatic nonunion

Correct Answer & Explanation

. Plate breakage at the surgical neck

Explanation

Intra-articular screw penetration is the most frequent hardware-related complication following locking plate fixation of proximal humerus fractures. It typically occurs secondary to varus collapse or settling of the humeral head fragment over the fixed-angle screws.

Question 7780

Topic: 2. Trauma

A 55-year-old man underwent open reduction and internal fixation with a locked plate for a 3-part proximal humerus fracture 6 months ago. He now presents with severe shoulder pain and a mechanical clicking sensation during elevation.

What is the most common hardware-related complication that leads to this presentation?

. Plate breakage
. Intra-articular screw penetration
. Subacromial impingement of the proximal plate
. Loosening of the cortical shaft screws
. Failure of the locking caps

Correct Answer & Explanation

. Plate breakage

Explanation

Intra-articular screw penetration is the most frequent hardware-related complication after locked plating of proximal humerus fractures. It often results from fracture settling, avascular necrosis, or unrecognized initial over-penetration, leading to secondary chondral damage and mechanical symptoms.

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