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2. Trauma MCQs

Practice Set 143 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 2841

Topic: Upper Extremity Trauma

A 55-year-old patient presents with an elbow injury following a fall onto an outstretched hand. Radiographs reveal an elbow dislocation, a comminuted radial head fracture, and a coronoid fracture. Based on the provided case, which of the following soft tissue structures is most consistently injured in this "terrible triad" pattern?

. A) Medial collateral ligament (MCL)
. B) Triceps tendon
. C) Lateral collateral ligament (LCL)
. D) Biceps tendon
. E) Posterior capsule

Correct Answer & Explanation

. C) Lateral collateral ligament (LCL)

Explanation

Correct Answer: CThe case explicitly states that with a terrible triad injury, soft tissue stabilizers of the elbow, such as the lateral collateral ligament, the anterior capsule of the elbow joint in association with the coronoid fracture, and possibly the medial collateral ligament, are expected to be injured. The LCL is a critical stabilizer against posterolateral rotatory instability, which is the common mechanism for terrible triad injuries. While the MCL can be involved, it is not as consistently injured as the LCL and anterior capsule in the initial injury pattern. The triceps tendon, biceps tendon, and posterior capsule are not typically considered primary structures injured in the terrible triad pattern.

Question 2842

Topic: 2. Trauma

A 48-year-old male is diagnosed with a terrible triad injury of the elbow. After initial radiographs confirm the diagnosis, what is the most crucial next step in imaging for detailed surgical planning, as highlighted in the case?

. A) MRI of the elbow
. B) Stress radiographs
. C) CT scan of the elbow
. D) Arthrography
. E) Dynamic ultrasound

Correct Answer & Explanation

. C) CT scan of the elbow

Explanation

Correct Answer: CThe case states: "A preoperative CT scan would provide useful information regarding the degree of comminution, fracture fragment origin, degree of displacement, and other factors to be considered during the operation." While MRI can show soft tissue injuries, and stress radiographs can assess instability, the CT scan is specifically highlighted as crucial for detailed bony assessment and surgical planning in this complex fracture-dislocation pattern.

Question 2843

Topic: 2. Trauma

A surgeon is performing an operative repair for a terrible triad injury. After excising radial head fragments, a small, comminuted coronoid fracture is encountered, deemed too small for direct screw fixation. Based on the case, what is the most appropriate management strategy for this specific coronoid injury?

. A) Excision of the coronoid fragment
. B) Leave the fragment in situ without repair
. C) Suture repair of the anterior capsule to the coronoid footprint using suture anchors
. D) Open reduction and internal fixation with multiple small K-wires
. E) Bone grafting of the coronoid defect

Correct Answer & Explanation

. C) Suture repair of the anterior capsule to the coronoid footprint using suture anchors

Explanation

Correct Answer: CThe case provides clear guidance: "If the coronoid fragment is too small to fix, I would perform a suture repair of the anterior capsule to the proximal ulna." It further elaborates in the operative sequence: "Depending on coronoid fragment size, I would reduce and fix the coronoid fracture with a single screw or I would suture the anterior capsule down to the coronoid footprint using suture anchors." This technique effectively reconstructs the anterior buttress of the coronoid when direct fixation is not feasible.

Question 2844

Topic: Upper Extremity Trauma

For the operative treatment of a terrible triad injury, the case describes a specific surgical approach. Which of the following approaches is recommended to gain access to the elbow joint and its surrounding structures?

. A) Anteromedial approach
. B) Direct lateral approach
. C) Utility posterior approach
. D) Medial epicondylar approach
. E) Anterolateral approach

Correct Answer & Explanation

. C) Utility posterior approach

Explanation

Correct Answer: CThe case explicitly states: "I would use the utility posterior approach to the elbow, raising thick flaps." This approach provides excellent visualization of the radial head, coronoid, and both medial and lateral collateral ligament complexes, which is essential for addressing all components of a terrible triad injury.

Question 2845

Topic: Upper Extremity Trauma

Prior to initiating the surgical incision for a terrible triad repair, proper patient positioning is crucial. According to the case, what is the recommended patient position for this procedure?

. A) Supine with the arm abducted
. B) Prone with the arm hanging free
. C) Lateral position with the affected arm over a bolster
. D) Beach chair position
. E) Semi-Fowler's position

Correct Answer & Explanation

. C) Lateral position with the affected arm over a bolster

Explanation

Correct Answer: CThe case specifies the patient positioning: "I would position the patient in the lateral position with the affected arm over a bolster." This position allows for gravity-assisted exposure and manipulation of the elbow, providing good access to both medial and lateral aspects of the joint, which is necessary for a comprehensive terrible triad repair.

Question 2846

Topic: 2. Trauma
A 45-year-old male presents after a fall onto an outstretched hand, sustaining a fracture of the proximal ulna and an anterior dislocation of the radial head. Which Bado classification type does this injury most accurately describe?
. Type I
. Type II
. Type III
. Type IV
. Galeazzi equivalent

Correct Answer & Explanation

. Type I

Explanation

The Bado classification defines Monteggia fractures based on the direction of radial head dislocation and the location/angulation of the ulnar fracture. Type I involves an anterior dislocation of the radial head with an associated anteriorly angulated ulnar shaft fracture. This is the most common variant, accounting for approximately 60% of all Monteggia injuries.

Question 2847

Topic: 2. Trauma

A 30-year-old male sustains a Monteggia Type I fracture. What is the generally accepted definitive treatment for an adult with this injury?

. Closed reduction and long-arm cast immobilization
. Open reduction and internal fixation (ORIF) of the ulnar fracture, which often reduces the radial head spontaneously
. Excision of the radial head and cast immobilization
. External fixation of the ulna
. Radial head arthroplasty

Correct Answer & Explanation

. Open reduction and internal fixation (ORIF) of the ulnar fracture, which often reduces the radial head spontaneously

Explanation

Correct Answer: BFor adult Monteggia fractures (of all types, but particularly Type I), the definitive treatment is almost universallyopen reduction and internal fixation (ORIF) of the ulnar fracture. Achieving stable anatomical reduction and fixation of the ulna is critical. In the vast majority of cases, once the ulna is anatomically reduced and stably fixed, the radial head will spontaneously reduce due to the intact interosseous membrane and annular ligament. Closed reduction is rarely successful or stable in adults. Excision of the radial head is not indicated for acute Monteggia fractures. External fixation might be considered in highly contaminated open fractures, but ORIF remains the standard. Radial head arthroplasty is indicated for severe comminuted radial head fractures, not primary Monteggia treatment.

Question 2848

Topic: 2. Trauma

Following successful ORIF of a Monteggia Type I fracture in an adult, the patient develops a posterior interosseous nerve (PIN) palsy. Which of the following is the most appropriate initial management step?

. Immediate surgical exploration of the PIN
. Observation and physiotherapy, as PIN palsies are often neurapraxic and resolve spontaneously
. Administration of high-dose corticosteroids
. EMG/NCS studies immediately to assess nerve damage
. Elbow immobilization in extension

Correct Answer & Explanation

. Observation and physiotherapy, as PIN palsies are often neurapraxic and resolve spontaneously

Explanation

Correct Answer: BPosterior interosseous nerve (PIN) palsy is a known, albeit uncommon, complication of Monteggia fractures or their treatment. The PIN is vulnerable as it courses through the supinator muscle. Most PIN palsies associated with Monteggia injuries are neurapraxias or axonotmesis due to traction or compression, and a significant proportion resolve spontaneously over several weeks to months. Therefore, the initial management is typicallyobservation, protection, and physiotherapy to prevent contractures, monitoring for recovery. Surgical exploration is generally reserved for cases that show no signs of recovery after 3-6 months. High-dose corticosteroids are not proven effective. EMG/NCS studies are usually performed after 3-4 weeks to establish a baseline or later if recovery is not observed. Immobilization in extension is not indicated and could cause stiffness.

Question 2849

Topic: 2. Trauma

What is a characteristic feature differentiating a Monteggia equivalent lesion from a classic Monteggia fracture?

. Involvement of the wrist joint
. Presence of a radial head fracture in addition to the ulnar fracture and radial head dislocation
. Occurrence only in pediatric patients
. No involvement of the annular ligament
. Absence of an ulnar shaft fracture

Correct Answer & Explanation

. Presence of a radial head fracture in addition to the ulnar fracture and radial head dislocation

Explanation

Correct Answer: BMonteggia equivalent lesions are a group of injuries that are biomechanically similar to Monteggia fractures (ulnar injury + radial head dislocation) but include additional or slightly different injury patterns. A common Monteggia equivalent is aMonteggia fracture with an associated fracture of the radial head (or neck) in addition to the ulnar fracture and radial head dislocation. Other equivalents include ulnar diaphyseal fracture with concomitant ipsilateral distal radial fracture, or proximal ulna physeal fracture with radial head dislocation. They are not limited to pediatric patients, and the annular ligament is almost always involved (torn or stretched). They do involve an ulnar injury, even if not always a diaphyseal fracture (e.g., physeal). Wrist joint involvement is typical for Essex-Lopresti, not standard Monteggia equivalents.

Question 2850

Topic: 2. Trauma

A 55-year-old patient presents with chronic elbow pain, limited pronation/supination, and a palpable radial head dislocation that was missed 6 months ago following a fall. Radiographs confirm a Monteggia Type I malunion with chronic anterior radial head dislocation. Which of the following is the most appropriate management option?

. Closed reduction and long-arm cast immobilization
. Corrective osteotomy of the ulna with open reduction of the radial head and annular ligament reconstruction
. Radial head excision alone
. Dynamic splinting to improve range of motion
. Elbow arthrodesis

Correct Answer & Explanation

. Corrective osteotomy of the ulna with open reduction of the radial head and annular ligament reconstruction

Explanation

Correct Answer: BA missed or chronic Monteggia fracture in an adult typically requires surgical intervention. For a chronic Monteggia Type I malunion, a staged approach often involves acorrective osteotomy of the malunited ulna to restore forearm length and rotation, followed by open reduction of the radial head. If the annular ligament is significantly disrupted or non-functional,reconstruction(e.g., using a strip of triceps fascia, forearm fascia, or allograft) is often necessary to stabilize the reduced radial head. Closed reduction is ineffective for chronic dislocations. Radial head excision alone in the presence of an intact ulna can lead to superior migration of the radius (Essex-Lopresti type sequela) and wrist pain due to disruption of forearm stability. Dynamic splinting may be used post-operatively but is not the primary treatment. Elbow arthrodesis is a salvage procedure for severe pain and instability, not initial management for a chronic Monteggia.

Question 2851

Topic: 2. Trauma

What unique challenge does a Bado Type IV Monteggia fracture present compared to other types?

. Increased risk of ulnar nerve injury
. Difficulty in determining the direction of radial head dislocation
. Necessity of fixing two diaphyseal fractures (ulna and radius) in addition to reducing the radial head
. Higher incidence of concomitant ipsilateral hand fractures
. Exclusive occurrence in open fracture scenarios

Correct Answer & Explanation

. Necessity of fixing two diaphyseal fractures (ulna and radius) in addition to reducing the radial head

Explanation

Correct Answer: CA Bado Type IV Monteggia fracture involves an anterior dislocation of the radial head, similar to Type I, but crucially includesfractures of both the ulna and the radial shaft. This presents a unique surgical challenge because the surgeon must address two diaphyseal fractures (ulna and radius) as well as ensuring concentric reduction and stability of the radial head. The goal remains anatomical reduction and stable fixation of both bone shafts, which typically leads to spontaneous radial head reduction. Other Monteggia types involve only an ulnar fracture. While nerve injuries or open fractures can occur, they are not specific differentiating challenges for Type IV.

Question 2852

Topic: 2. Trauma

What is the primary role of the interosseous membrane in a Monteggia fracture?

. To provide direct blood supply to the radius and ulna
. To act as a strong stabilizer, transmitting forces between the radius and ulna and helping to maintain radial head reduction after ulnar fixation
. To prevent compartment syndrome in the forearm
. To facilitate pronation and supination movements
. To absorb impact forces at the wrist

Correct Answer & Explanation

. To act as a strong stabilizer, transmitting forces between the radius and ulna and helping to maintain radial head reduction after ulnar fixation

Explanation

Correct Answer: BThe interosseous membrane (IOM) is a crucial stabilizer of the forearm. In the context of a Monteggia fracture, the IOM acts as a strong anatomical link between the radius and ulna. Its tension is critical; when the ulnar fracture is anatomically reduced and stably fixed, the tension in the IOM typically draws the radial head back into position andhelps maintain its reduction by ensuring proper length and alignment of the forearm bones. The IOM does not primarily provide blood supply or prevent compartment syndrome, nor does it solely facilitate pronation/supination (though it influences it). It plays a vital role in force transmission and longitudinal stability.

Question 2853

Topic: 2. Trauma
A 55-year-old male presents with a fracture of the proximal third of the ulna with apex posterior angulation and an associated posterior dislocation of the radial head. According to the Bado classification, what type of Monteggia lesion is this?
. Type I
. Type II
. Type III
. Type IV
. Type V

Correct Answer & Explanation

. Type II

Explanation

A Bado Type II Monteggia fracture is characterized by a diaphyseal or metaphyseal fracture of the ulna with apex posterior angulation and posterior dislocation of the radial head. It is the most common type seen in adults and is frequently associated with radial head fractures.

Question 2854

Topic: 2. Trauma

A 38-year-old male sustains a terrible triad injury. Imaging shows a Regan-Morrey Type I (tip) coronoid fracture. Which of the following describes the most appropriate management of this specific coronoid fragment during surgery?

. Excision of the fragment and no further repair
. Lag screw fixation from anterior to posterior
. Suture lasso technique through drill holes in the proximal ulna to repair the anterior capsule
. Micro-fragment plate fixation applied to the coronoid tip
. Conservative management without addressing the coronoid

Correct Answer & Explanation

. Suture lasso technique through drill holes in the proximal ulna to repair the anterior capsule

Explanation

Small Type I (tip) coronoid fractures represent an avulsion of the anterior capsule and are often too small for screw fixation. They provide critical soft-tissue stability and are best managed by capturing the capsule and fragment using a suture lasso technique tied through the proximal ulna.

Question 2855

Topic: Upper Extremity Trauma

Following surgical repair of a terrible triad injury of the elbow, the patient is started on early active range of motion. To maximally protect the lateral collateral ligament (LCL) repair during elbow extension, in what position should the forearm be maintained?

. Supination
. Pronation
. Neutral rotation
. Maximal internal rotation
. Maximal external rotation

Correct Answer & Explanation

. Pronation

Explanation

Pronation of the forearm tightens the medial soft tissues and the extensor origin, effectively protecting the LCL repair from varus and posterolateral rotatory stress. Early active motion is typically performed with the forearm in pronation.

Question 2856

Topic: 2. Trauma
A 6-year-old boy presents with an elbow injury. Radiographs reveal a fracture of the ulnar metaphysis with a lateral dislocation of the radial head. What Bado classification does this injury represent?
. Type I
. Type II
. Type III
. Type IV
. Type V

Correct Answer & Explanation

. Type III

Explanation

A Bado Type III Monteggia lesion involves a metaphyseal fracture of the ulna with a lateral dislocation of the radial head. It occurs almost exclusively in children and is frequently associated with posterior interosseous nerve (PIN) injuries.

Question 2857

Topic: 2. Trauma

In the setting of a terrible triad injury, at what point during the operation is the repair of the medial collateral ligament (MCL) primarily indicated?

. Routinely prior to LCL repair
. Only if there is a concomitant medial epicondyle fracture
. If the elbow remains unstable in extension after coronoid, radial head, and LCL repairs
. Always, as the MCL is the primary stabilizer against valgus stress
. Never, as the MCL heals reliably without surgery

Correct Answer & Explanation

. If the elbow remains unstable in extension after coronoid, radial head, and LCL repairs

Explanation

Routine repair of the MCL is not indicated in all terrible triad injuries. It is typically explored and repaired only if the elbow demonstrates residual instability in extension after the coronoid, radial head, and lateral-sided structures have been securely fixed.

Question 2858

Topic: 2. Trauma

A 32-year-old male sustains a Bado Type I Monteggia fracture. Which of the following represents the gold standard of treatment for the ulnar shaft fracture in this adult patient?

. Closed reduction and long arm casting in supination
. Intramedullary nailing
. Open reduction and internal fixation with compression plating
. External fixation
. Functional bracing

Correct Answer & Explanation

. Open reduction and internal fixation with compression plating

Explanation

In adults, all Monteggia fractures require open reduction and internal fixation (ORIF) of the ulna to ensure anatomic alignment and rigid stability. Compression plating is the gold standard because intramedullary devices do not provide adequate rotational control.

Question 2859

Topic: 2. Trauma

While reviewing elbow trauma cases, a resident notes a fracture involving the anteromedial facet of the coronoid. This specific fracture pattern is most commonly associated with which mechanism and injury pattern?

. Valgus extension overload in throwing athletes
. Varus posteromedial rotatory instability (VPMRI)
. Direct axial load causing an olecranon fracture-dislocation
. Standard terrible triad injury with LCL disruption
. Isolated radial head fracture

Correct Answer & Explanation

. Varus posteromedial rotatory instability (VPMRI)

Explanation

Fractures of the anteromedial facet of the coronoid are the hallmark of varus posteromedial rotatory instability (VPMRI). They typically occur from a varus force coupled with an axial load and are often associated with LCL tears, requiring specific fixation to prevent rapid arthrosis.

Question 2860

Topic: 2. Trauma

A 45-year-old male is involved in a motor vehicle collision. Radiographs of the forearm demonstrate fractures of both the radial and ulnar shafts, along with an anterior dislocation of the radial head. How is this injury classified?

. Bado Type I Monteggia
. Bado Type IV Monteggia
. Galeazzi fracture-dislocation
. Essex-Lopresti injury
. Nightstick fracture

Correct Answer & Explanation

. Bado Type IV Monteggia

Explanation

A Bado Type IV Monteggia lesion is defined by a dislocation of the radial head (usually anterior) accompanied by diaphyseal fractures of both the radius and the ulna. It requires rigid internal fixation of both forearm bones.

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