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2. Trauma MCQs

Practice Set 233 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 4641

Topic: Upper Extremity Trauma

A 42-year-old bodybuilder feels a pop in his posterior elbow during heavy triceps extensions. He has loss of active elbow extension against resistance. MRI confirms a complete avulsion of the triceps tendon from the olecranon. During surgical repair, passing sutures through transosseous drill holes in the olecranon is planned. Which configuration provides the strongest biomechanical repair for triceps avulsion?

. Single simple suture
. Figure-of-eight suture alone
. Krackow locking stitch with transosseous cruciate configuration
. Anchor fixation without transosseous sutures
. Mattress suture

Correct Answer & Explanation

. Single simple suture

Explanation

Biomechanical studies have demonstrated that a modified Krackow locking stitch in the triceps tendon passed through transosseous drill holes in a cruciate (crossed) configuration provides superior construct strength and minimizes gap formation compared to simple, mattress, or figure-of-eight configurations.

Question 4642

Topic: 2. Trauma
A 35-year-old female sustains a coronal shear fracture of the distal humerus involving the capitellum that extends medially to include the majority of the trochlea. Which classification applies to this fracture pattern?
. Hahn-Steinthal fracture (Type I)
. Kocher-Lorenz fracture (Type II)
. Broberg-Morrey fracture (Type III)
. McKee's modification (Type IV)
. Jupiter Type V

Correct Answer & Explanation

. McKee's modification (Type IV)

Explanation

McKee's modification (Type IV) to the Bryan and Morrey classification describes a coronal shear fracture of the capitellum that extends medially to involve most or all of the trochlea. Type I is a large osseous capitellar fragment. Type II is a cartilaginous shell. Type III is comminuted.

Question 4643

Topic: 2. Trauma

In a 'terrible triad' injury of the elbow (elbow dislocation, radial head fracture, and coronoid fracture), the coronoid fracture typically corresponds to which pattern according to the O'Driscoll classification?

. Tip (Type 1)
. Anteromedial facet (Type 2)
. Base (Type 3)
. Comminuted involving the sublime tubercle
. Transverse mid-substance

Correct Answer & Explanation

. Tip (Type 1)

Explanation

Terrible triad injuries of the elbow typically feature a transverse fracture of the coronoid tip (O'Driscoll Type 1). Anteromedial facet fractures are associated with varus posteromedial rotatory instability, and base fractures are often seen in anterior olecranon fracture-dislocations.

Question 4644

Topic: 2. Trauma

A 40-year-old male with a conservatively treated midshaft clavicle fracture 5 years ago presents with arm fatigue, numbness, and tingling in the ulnar digits when working overhead. Imaging reveals a hypertrophic nonunion of the clavicle. Which structure is most likely being directly compressed by the callus?

. Musculocutaneous nerve
. Medial cord of the brachial plexus
. Lateral cord of the brachial plexus
. Axillary artery
. Axillary nerve

Correct Answer & Explanation

. Musculocutaneous nerve

Explanation

Hypertrophic callus or nonunion of the middle third of the clavicle can impinge upon the underlying neurovascular structures in the thoracic outlet. The medial cord of the brachial plexus (which contributes to the ulnar nerve) and the subclavian vessels are at greatest risk.

Question 4645

Topic: 2. Trauma
According to the Bado classification, a Monteggia fracture-dislocation characterized by a metaphyseal fracture of the proximal ulna with a posterior dislocation of the radial head is classified as:
. Type I
. Type II
. Type III
. Type IV
. Type V

Correct Answer & Explanation

. Type II

Explanation

In the Bado classification of Monteggia injuries: Type I involves anterior dislocation of the radial head; Type II involves posterior dislocation; Type III involves lateral dislocation; Type IV involves fractures of both the radius and ulna with anterior radial head dislocation.

Question 4646

Topic: Upper Extremity Trauma

The anterior bundle of the ulnar collateral ligament (UCL) of the elbow originates from the anteroinferior surface of the medial epicondyle and inserts onto which structure?

. Olecranon tip
. Sublime tubercle of the coronoid process
. Radial neck
. Annular ligament
. Brachialis tendon insertion

Correct Answer & Explanation

. Olecranon tip

Explanation

The anterior bundle of the UCL is the primary restraint to valgus stress at the elbow. It originates on the medial epicondyle and inserts on the sublime tubercle, which is located on the medial aspect of the coronoid process.

Question 4647

Topic: 2. Trauma

A 37-year-old male sustained the injury shown in figure A. He was treated with an intramedurally nail and a post-operative radiograph is shown in figure B. He underwent a post-operative CT Scanogram to assess for rotation. Figures C and D are of the operative side and Figures E and F are of the uninjured side. What is the version of the injured side and should any further procedures be undertaken for correction?

. Femoral anteversion of 36 degrees, no further procedures required
. Femoral anteversion of 36 degrees, to undergo femoral de-rotation
. Neutral version, no further procedures required
. Neutral version, to undergo femoral de-rotation
. Femoral retroversion of 36 degrees, to undergo femoral de-rotationCorrent answer: 3This patient has neutral version on the operative side and 6 degrees of anteversion on the normal side, therefore no further procedures are required.Rotational malalignment or torsional deformity is expressed as a difference in femoral version between the injured and uninjured leg. It can be measured clinically, radiograpically, and most accurately by CT scan. CT scan is the method of choice because of its reliability and reproducibility. The incidence of rotational malalignment may be as high 30% in some fracture patterns.Fracture comminution is a risk for rotational malalignment as it alters the ability to obtain a cortical read. Differences between sides of <10 degrees are considered variations of normal while differences of >15 degrees are considered true torsional deformities and likely require de-rotation.Jaarsma et al. detail how to obtain a rotational profile of the femur. Rotational alignment is determined by the angle between a line tangential to the femoral condyles and a line drawn through the axis of the femoral neck. The difference in angle between the fractured and unaffected side determines the rotational alignment. A decrease in anteversion of the femoral neck of the fractured side implies increased external rotation and an increase denotes increased internal rotation of the distal fragment.Koerner et al. measured 328 normal femora and found that there were no statistically significant differences in mean version between African American, white, and Hispanic patients for males or females. They found retroversion to be common in white males, African American males, and all females. They conclude that this may have implications in proper alignment restoration after IM nailing of femur fractures.Gardner et al. performed a cadeveric study and found that freehand distal interlocking may be a substantial cause of rotational deformity. They found that freehand insertion may cause a 7 degree change in alignment. They saw that when inserting the drill freehand, drill/nail contact caused a visible shift of the fracture site. They conclude that the use of computer navigation systems may improve this issue.Figure A demonstrates a subtrochanteric femur fracture, while Figure B demonstrates the same fracture, stabilized with a piriformis entry nail. Figures C-F demonstrate axial CT cuts to determine femoral version. Figure C demonstrates hip anteversion of 18 degrees, while figure D reveals knee external rotation of 18 degrees. This side exhibits neutral rotation (18-18).Figure E demonstrates hip anteversion of 9.2 degrees while figure F demonstrates knee external rotation of 3.2 degrees. This side exhibits 6 degrees of anteversion (9.2-3.2).Incorrect Answers:

Correct Answer & Explanation

. Neutral version, to undergo femoral de-rotation

Explanation

OrthoCash 2020

Question 4648

Topic: 2. Trauma
A 14-year-old boy undergoes application of a circular frame with tibial and fibular osteotomy for gradual limb lengthening. He initiates lengthening 7 days after surgery. During the first week of lengthening, he reports that turning of the distraction devices is becoming increasingly difficult. On the 9th day of lengthening, he is seen in the emergency department after feeling a pop in his leg and noting the acute onset of severe pain. What complication has most likely occurred?
. Joint subluxation and acute ligament rupture
. Incomplete corticotomy at the time of surgery with spontaneous completion and acute distraction
. Premature consolidation of the osteotomy with breakage of bone transfixation wire
. Fracture through the bone regenerate
. Fracture of the tibia through a unicortical half-pin track

Correct Answer & Explanation

. Incomplete corticotomy at the time of surgery with spontaneous completion and acute distraction

Explanation

Incomplete corticotomy may result from osteotomy with limited soft-tissue stripping and exposure. When the patient begins distraction, tension develops at all wire/half-pin and bone interfaces, leading to increasing difficulty in distraction and limb pain. Sudden spontaneous completion of the osteotomy with continued tension applied by the fixator results in acute distraction of the osteotomy with severe pain. Premature consolidation is unlikely this early following the initial surgery.

Question 4649

Topic: 2. Trauma
A 17-year-old man sustained a 5-mm laceration on the lateral aspect of the hindfoot while working on a farm. Examination in the emergency department revealed no fractures. Twenty-four hours later, he returns to the emergency department with increasing foot pain. Thin brown drainage is seen emanating from the wound. He has a temperature of 102.0° F (38.9° C), a pulse rate of 120, and a blood pressure of 80/40 mm Hg. Examination of the foot reveals diffuse swelling, ecchymosis, tenderness, and crepitus with palpation. Current radiographs are shown in Figures 40a and 40b. Management should now consist of
. Intravenous antibiotics.
. Hyperbaric oxygen therapy and intravenous antibiotics.
. Surgical debridement, primary wound closure, and intravenous antibiotics.
. Surgical debridement, closure of the wound over drains, and intravenous antibiotics.
. Surgical debridement, leaving the wound open, and intravenous antibiotics.

Correct Answer & Explanation

. Surgical debridement, leaving the wound open, and intravenous antibiotics.

Explanation

The mechanism and environment in which the injury occurred, the clinical picture, and the radiographic findings of gas in the tissues suggest an anaerobic Gram-positive bacterial infection. This can be a life- and limb-threatening infection. Treatment should consist of wide debridement of all devitalized tissue, and intravenous antibiotics should be started. Wounds should be left open to allow bacterial effluent and increase oxygen tension in the wound. Hyperbaric oxygen may be used as an adjuvant but is no substitute for debridement.

Question 4650

Topic: 2. Trauma
Figures 1 through 3 are the clinical photograph and radiographs of a 25-year-old, left-hand-dominant man who injured his left index finger. Which treatment option will most effectively allow satisfactory fracture alignment and maximize motion?
. Buddy-taping to the long finger with an early range of motion (ROM) program
. Closed reduction and static external fixation in extension
. Open reduction and internal fixation (ORIF) with an early ROM program
. Digital splinting for 4 weeks followed by a ROM program

Correct Answer & Explanation

. Open reduction and internal fixation (ORIF) with an early ROM program

Explanation

This patient has an oblique index proximal phalanx fracture with malrotation. Buddy-taping and digital splinting would not predictably maintain fracture reduction and would result in a malunion with rotational deformity and possible shortening. Closed reduction and spanning external fixation in extension would result in significant digital stiffness. ORIF followed by an early ROM program would allow anatomic fracture alignment and give this patient the best chance to regain the majority of motion in the shortest amount of time.

Question 4651

Topic: 2. Trauma

What is the most common complication following surgery for a "terrible triad" elbow fracture-dislocation?

. Arthritis
. Infection
. Re-dislocation
. Restricted range of elbow motion
. Posterior interosseous nerve (PIN) palsy

Correct Answer & Explanation

. Restricted range of elbow motion

Explanation

Recurrent instability, PIN palsy, infection, and posttraumatic arthritis have all been reported following these injuries; however, elbow contracture or loss of motion is nearly universal following these injuries.

Question 4652

Topic: 2. Trauma

A 45-year-old man undergoes open reduction and internal fixation of a Schatzker VI tibial plateau fracture. In the recovery room, he complains of severe, unrelenting pain out of proportion to the injury, significantly worsened by passive stretch of the hallux. His blood pressure is 110/70 mmHg. Intracompartmental pressure monitoring of the anterior compartment reveals a pressure of 45 mmHg. What is the most appropriate management?

. Elevate the leg above the level of the heart and administer IV analgesics
. Release all dressings and bivalve the splint, then reassess in 2 hours
. Administer a bolus of IV mannitol and begin hyperbaric oxygen therapy
. Perform immediate four-compartment fasciotomies of the leg
. Perform a single-incision fasciotomy of the anterior compartment

Correct Answer & Explanation

. Elevate the leg above the level of the heart and administer IV analgesics

Explanation

The patient is exhibiting clinical signs of acute compartment syndrome. The diagnosis is confirmed by calculating the delta pressure (Diastolic Blood Pressure minus Intracompartmental Pressure). His diastolic BP is 70 mmHg and his compartment pressure is 45 mmHg, yielding a delta pressure of 25 mmHg. A delta pressure less than 30 mmHg is an absolute indication for emergent four-compartment fasciotomy. Elevation of the limb decreases arterial perfusion and is contraindicated. Releasing dressings is a necessary initial step, but given the critical delta pressure and clinical signs, definitive surgical decompression cannot be delayed.

Question 4653

Topic: 2. Trauma

An 82-year-old female sustains a highly comminuted extra-articular distal femur fracture (OTA/AO 33-A3). She is treated with a lateral locking plate using a bridge plating technique. Which of the following technical factors most significantly increases the risk of hypertrophic nonunion due to an overly stiff construct?

. Using a titanium plate rather than a stainless steel plate
. Maintaining a plate span ratio of 3:1
. Using a working length of four plate holes over the fracture site
. Placing locking screws in the holes immediately adjacent to the fracture site
. Using unicortical locking screws in the diaphyseal segment

Correct Answer & Explanation

. Using a titanium plate rather than a stainless steel plate

Explanation

In bridge plating of comminuted fractures, relative stability is desired to promote secondary bone healing (callus formation). The construct must allow for micro-motion at the fracture site to generate the optimal strain for callus formation (between 2% and 10%). Placing locking screws immediately adjacent to the fracture site significantly decreases the 'working length' of the plate, creating an overly stiff construct. This extreme rigidity decreases interfragmentary strain below the threshold required for callus formation, increasing the risk of delayed union, nonunion, or eventual hardware failure.

Question 4654

Topic: Pelvic & Acetabular Trauma

A 35-year-old male sustains an Anterior-Posterior Compression type II (APC-II) pelvic ring injury following a crush injury at a construction site. On arrival, he is hemodynamically unstable despite initial fluid resuscitation. What is the most common anatomic source of major hemorrhage in this type of injury?

. Superior gluteal artery
. Obturator artery
. Venous presacral plexus and fractured cancellous bone
. Internal pudendal artery
. Median sacral artery

Correct Answer & Explanation

. Superior gluteal artery

Explanation

While arterial bleeding (such as from the superior gluteal or internal pudendal arteries) can cause rapid, life-threatening exsanguination and is the target for pelvic angioembolization, the most common overall source of hemorrhage in pelvic ring fractures is venous bleeding from the presacral venous plexus and the exposed cancellous bone surfaces. This low-pressure bleeding is typically managed initially by reducing pelvic volume (e.g., pelvic binder) to promote tamponade.

Question 4655

Topic: 2. Trauma
A 40-year-old male sustains a high-energy Gustilo-Anderson IIIB open fracture of the distal third of the tibia. After aggressive surgical debridement and application of an external fixator, a 5 cm x 8 cm soft tissue defect with exposed denuded bone remains. Which of the following soft tissue coverage options provides the most reliable and robust vascularized coverage for this specific anatomical region?
. Medial gastrocnemius rotational flap
. Soleus rotational flap
. Free vascularized latissimus dorsi flap
. Reverse sural artery fasciocutaneous flap
. Split-thickness skin graft directly over the exposed bone

Correct Answer & Explanation

. Free vascularized latissimus dorsi flap

Explanation

Soft tissue coverage for the tibia is classically divided into thirds. The proximal third is typically covered by a medial or lateral gastrocnemius rotational flap. The middle third is covered by a soleus rotational flap. The distal third, due to limited local muscle bulk, generally requires a free tissue transfer (such as a latissimus dorsi, rectus abdominis, or gracilis muscle free flap) for reliable coverage, especially in high-energy Gustilo IIIB injuries. While the reverse sural flap is an option for smaller defects, a free vascularized muscle flap is the most reliable choice for a defect of this size with exposed bone.

Question 4656

Topic: 2. Trauma
A 26-year-old female sustains a vertical, transcervical femoral neck fracture (Pauwels Type III) following a fall from a horse. Which of the following internal fixation constructs provides the greatest biomechanical resistance to vertical shear forces for this fracture pattern?
. Three parallel cancellous screws placed in an inverted triangle configuration
. Two parallel cancellous screws placed perpendicular to the fracture line
. A sliding hip screw (DHS) combined with an anti-rotation cancellous screw
. A cephalomedullary nail utilizing dual integrated interlocking head screws
. Three parallel fully-threaded cortical screws

Correct Answer & Explanation

. A sliding hip screw (DHS) combined with an anti-rotation cancellous screw

Explanation

Pauwels Type III femoral neck fractures have a vertical orientation (>50 degrees), which subjects the fracture site to exceptionally high shear forces rather than compressive forces. Biomechanical studies demonstrate that a fixed-angle construct, such as a sliding hip screw (dynamic hip screw, DHS), provides superior resistance to vertical shear forces compared to multiple parallel cancellous screws. An anti-rotation screw is often added to prevent rotation of the femoral head during insertion and subsequent loading. Parallel cancellous screws are primarily indicated for more horizontal fractures (Pauwels I or II) where compressive forces predominate.

Question 4657

Topic: 2. Trauma

A polytrauma patient with a femur fracture, blunt chest trauma, and a closed head injury has been resuscitated over the past 24 hours. The trauma team is evaluating whether the patient is physiologically ready for transitioning from "Damage Control Orthopedics" (DCO) to definitive fracture fixation ("Early Total Care"). Normalization of which of the following physiological parameters is the most reliable indicator of adequate resuscitation?

. White blood cell count
. Serum interleukin-6 (IL-6) levels
. Serum base excess and serum lactate
. Core body temperature > 37.5 degrees Celsius
. Mean arterial pressure > 60 mmHg

Correct Answer & Explanation

. White blood cell count

Explanation

The decision to convert from damage control orthopedics to definitive fracture care relies heavily on the normalization of systemic perfusion and the clearance of shock markers. A normalized serum lactate (< 2.0 mmol/L) and a base excess resolving to within normal limits (-2 to +2 mEq/L) are the most widely accepted and reliable biochemical markers indicating adequate resuscitation and restoration of tissue perfusion, thereby minimizing the 'second hit' phenomenon associated with definitive surgical intervention.

Question 4658

Topic: 2. Trauma

A 65-year-old osteoporotic female undergoes open reduction and internal fixation of a 3-part proximal humerus fracture using a fixed-angle locking plate. To minimize the risk of post-operative varus collapse and subsequent intra-articular screw penetration, which specific technical maneuver is most critical during fixation?

. Placement of a locking screw into the inferomedial quadrant of the humeral head (calcar screw)
. Tension band wiring of the greater tuberosity to the rotator cuff tendon
. Placing the superior border of the plate flush with the tip of the greater tuberosity
. Utilizing exclusively unicortical screws in the humeral shaft
. Medializing the humeral shaft fragment to intentionally create a valgus impaction

Correct Answer & Explanation

. Placement of a locking screw into the inferomedial quadrant of the humeral head (calcar screw)

Explanation

In the operative management of proximal humerus fractures with locking plates, the loss of medial support (the medial hinge) is a primary risk factor for failure via varus collapse and screw cut-out. Placement of a well-positioned inferomedial locking screw (the 'calcar screw') into the inferomedial quadrant of the humeral head mechanically supports the medial cortex and significantly increases the biomechanical resistance to varus loads, thereby preventing construct failure.

Question 4659

Topic: 2. Trauma

A 4-year-old boy presents with an isolated spiral midshaft femur fracture after falling from a playground slide. Radiographs reveal 1.5 cm of shortening and 10 degrees of varus angulation. There is no evidence of non-accidental trauma. What is the most appropriate definitive management for this patient?

. Application of a Pavlik harness
. Early application of a hip spica cast
. Closed reduction and placement of flexible intramedullary nails (ESIN)
. Open reduction and plate fixation
. Rigid antegrade intramedullary nailing

Correct Answer & Explanation

. Application of a Pavlik harness

Explanation

For pediatric diaphyseal femur fractures, treatment algorithms are heavily based on age. Children aged 6 months to 5 years with an isolated femur fracture and < 2 cm of shortening are definitively treated with early closed reduction and hip spica casting. Pavlik harnesses are typically reserved for infants < 6 months of age. Flexible intramedullary nails (Elastic Stable Intramedullary Nailing, ESIN) are the treatment of choice for children aged 5 to 11 years. Rigid intramedullary nailing is contraindicated in young children due to the risk of avascular necrosis of the femoral head and greater trochanteric apophyseal arrest.

Question 4660

Topic: 2. Trauma

A 48-year-old female sustains a closed, high-energy tibial pilon fracture (OTA/AO 43-C3) in a motor vehicle collision. On arrival, her distal lower extremity is grossly deformed, excessively swollen, and taut, with early hemorrhagic fracture blisters forming. She is hemodynamically stable. What is the most appropriate initial orthopedic intervention?

. Application of a well-padded bivalved short leg cast
. Immediate definitive open reduction and internal fixation of both the fibula and tibia
. Application of a spanning external fixator across the ankle joint
. Prophylactic fasciotomies of the lower extremity followed by a splint
. Immediate fibular plating followed by temporary external fixation of the tibia

Correct Answer & Explanation

. Application of a well-padded bivalved short leg cast

Explanation

High-energy tibial pilon fractures are associated with profound soft tissue injury. Immediate definitive fixation (ORIF) in the presence of severe swelling and fracture blisters is associated with extremely high rates of wound dehiscence and deep infection. The standard of care is a staged protocol ('span, scan, and plan'): immediate application of a spanning external fixator across the ankle joint to restore length, alignment, and provide stability, allowing the soft tissues to declare themselves and swellings to subside over 10-21 days before definitive internal fixation is attempted.

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