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2. Trauma MCQs

Practice Set 483 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 9641

Topic: 2. Trauma

Which of the following is most likely to impede closed reduction of a radial head dislocation in an adult Monteggia fracture?

. Chronic muscle spasm
. Swelling and ecchymosis
. Elbow joint effusion
. Intra-articular entrapment of the annular ligament
. Fear and anxiety of the patient

Correct Answer & Explanation

. Intra-articular entrapment of the annular ligament

Explanation

In both adults and children, the most common reason for failure of closed reduction of the radial head in a Monteggia fracture is mechanical obstruction due to intra-articular soft tissue interposition. This is most frequently the torn annular ligament, which can become trapped (buttonholed) within the radiocapitellar joint, preventing concentric reduction. While other factors like muscle spasm, swelling, or patient anxiety can make reduction more difficult, they don't typically represent an absolute mechanical block to reduction like an entrapped ligament.

Question 9642

Topic: 2. Trauma
What is the typical age range for a Bado Type III Monteggia fracture to occur?
. Infants (0-1 year)
. Toddlers and young children (3-10 years)
. Adolescents (12-18 years)
. Young adults (20-40 years)
. Elderly (over 65 years)

Correct Answer & Explanation

. Toddlers and young children (3-10 years)

Explanation

Bado Type III Monteggia fractures, characterized by a ulnar metaphyseal fracture and lateral or anterolateral radial head dislocation, are most common in toddlers and young children, typically between 3 and 10 years of age. This is due to the greater elasticity of pediatric bones, which often results in plastic deformation or greenstick fractures of the ulna rather than complete diaphyseal fractures, combined with ligamentous laxity. These injuries can be subtle and are prone to being missed.

Question 9643

Topic: 2. Trauma

What is the primary management goal for a Monteggia equivalent injury where a child has an ulnar shaft fracture and an associated radial neck fracture with radial head dislocation?

. Radial head excision to prevent nonunion of the radial neck fracture
. Closed reduction of the radial neck fracture and radial head dislocation, followed by ulnar fracture fixation if needed
. Immediate ORIF of both the radial neck and ulnar shaft fractures
. External fixation for both fractures
. Observation and sling immobilization

Correct Answer & Explanation

. Closed reduction of the radial neck fracture and radial head dislocation, followed by ulnar fracture fixation if needed

Explanation

In pediatric Monteggia equivalents with an associated radial neck fracture and radial head dislocation, the primary goal is often to achieve closed reduction of the radial head and neck. If successful, this can be maintained with casting. The ulnar fracture (if present) is then addressed; if it's a stable pattern (e.g., greenstick), casting may suffice; if unstable, it may require fixation. Radial head excision is generally avoided in children due to growth disturbance and long-term wrist issues. ORIF of the radial neck is reserved for irreducible or significantly displaced fractures after failed closed attempts. The principle is still to restore the radiocapitellar articulation while addressing the bony injuries.

Question 9644

Topic: 2. Trauma

What is a characteristic finding of a Monteggia Type II fracture on a lateral radiograph?

. Anterior dislocation of the radial head and anterior angulation of the ulnar fracture
. Posterior dislocation of the radial head and posterior angulation of the ulnar fracture
. Lateral displacement of the radial head with an ulnar metaphyseal fracture
. Radial head fracture with anterior ulnar angulation
. Elbow joint widening

Correct Answer & Explanation

. Posterior dislocation of the radial head and posterior angulation of the ulnar fracture

Explanation

Bado Type II Monteggia fractures are defined by a posterior dislocation of the radial head and a posteriorly angulated ulnar shaft fracture. On a lateral radiograph, this would be visible as the radial head lying posterior to the capitellum, and the fracture fragments of the ulna would be angled such that the apex of the deformity points anteriorly (posterior angulation). The other options describe different Monteggia types or non-specific findings.

Question 9645

Topic: 2. Trauma

A Monteggia fracture in an adult with an associated posterior interosseous nerve palsy is diagnosed. The nerve palsy is complete (no active extension of the MCP joints or thumb). What is the recommended management strategy?

. Immediate surgical exploration of the nerve
. Closed reduction of the fracture and immobilization, followed by observation of nerve recovery
. Referral for nerve conduction studies within 24 hours
. Initiate high-dose corticosteroids for nerve protection
. Surgical repair of the ulnar fracture but no specific intervention for the nerve

Correct Answer & Explanation

. Closed reduction of the fracture and immobilization, followed by observation of nerve recovery

Explanation

In the presence of an acute Monteggia fracture with an associated posterior interosseous nerve (PIN) palsy, the standard approach is to perform definitive treatment of the fracture (e.g., ORIF for adults, closed reduction for children). Following reduction of the fracture and radial head, the PIN palsy is typically observed. Most PIN palsies associated with Monteggia fractures are neurapraxias due to traction or compression and resolve spontaneously over weeks to months. Immediate surgical exploration of the nerve is generally reserved for cases that show no signs of recovery after 3-6 months. Nerve conduction studies are usually not helpful acutely and are better done later to assess recovery. Corticosteroids are not indicated.

Question 9646

Topic: 2. Trauma

Which statement about the prognosis of Monteggia fractures in children is generally true?

. Always results in significant functional impairment regardless of treatment.
. Excellent prognosis with anatomical reduction and stable fixation, even with delayed presentation if treated surgically.
. Significantly worse prognosis than in adults due to growth plate involvement.
. Often requires multiple revision surgeries due to bone remodeling.
. Closed reduction success rate is very low in children.

Correct Answer & Explanation

. Excellent prognosis with anatomical reduction and stable fixation, even with delayed presentation if treated surgically.

Explanation

Monteggia fractures in children generally have an excellent prognosis, even with delayed presentation (up to a few weeks/months) if treated with anatomical reduction and stable fixation (often closed reduction and casting, sometimes open reduction). The high remodeling potential of pediatric bone and the strong capacity for annular ligament healing contribute to good outcomes. Prompt and accurate treatment is key. While growth plate involvement is a concern in any pediatric fracture, most Monteggia injuries don't directly involve the radial head physis in a way that causes severe growth arrest. Closed reduction success rates are generally high for acute pediatric Monteggia fractures.

Question 9647

Topic: 2. Trauma
What is the typical presentation of a Monteggia Type III fracture in a young child?
. Significant elbow deformity with posterior dislocation of the radial head.
. Pain and swelling of the elbow with a subtle greenstick fracture of the ulnar metaphysis and lateral radial head dislocation.
. Severe comminuted fractures of both the radius and ulna.
. Wrist pain and inability to pronate/supinate.
. Palpable radial head in the cubital fossa.

Correct Answer & Explanation

. Pain and swelling of the elbow with a subtle greenstick fracture of the ulnar metaphysis and lateral radial head dislocation.

Explanation

Monteggia Type III fractures are common in young children and are characterized by a fracture of the ulnar metaphysis (often a greenstick or plastic deformation) and a lateral or anterolateral dislocation of the radial head. The clinical presentation is often pain and swelling around the elbow, but the bony deformity might be subtle compared to other types, making it prone to being missed. Other options describe different Monteggia types, severe trauma, or wrist injuries.

Question 9648

Topic: 2. Trauma

When managing a Monteggia fracture in an adult, what is considered the gold standard for ulnar fixation?

. Intramedullary K-wires
. Anterior plating with lag screws
. Posterior plating with a dynamic compression plate
. External fixation
. Plate and screw fixation (dynamic or locking compression plate) applied to the stable aspect of the ulna

Correct Answer & Explanation

. Plate and screw fixation (dynamic or locking compression plate) applied to the stable aspect of the ulna

Explanation

For adult Monteggia fractures, the gold standard for stabilizing the ulnar fracture is open reduction and internal fixation (ORIF) with a plate and screws. Dynamic compression plates (DCP) or locking compression plates (LCP) provide stable fixation, restore anatomical length and alignment, and permit early mobilization. The plate is applied to the stable side of the ulna (e.g., usually the dorsal or posteromedial surface for Type I/II to accommodate muscle attachments and nerve trajectories), providing optimal biomechanical stability. Intramedullary wires and external fixators are generally not suitable for definitive diaphyseal ulnar fixation in adults. Anterior plating is less common due to muscle bulk and neurovascular structures.

Question 9649

Topic: 2. Trauma

In the immediate post-operative period after ORIF of a Monteggia fracture in an adult, what is the most important component of the rehabilitation protocol?

. Aggressive strengthening exercises for the elbow flexors and extensors
. Strict immobilization for 6 weeks in a cast to ensure bone healing
. Early controlled range of motion exercises (flexion, extension, pronation, supination) as tolerated
. Weight-bearing through the elbow to promote bone consolidation
. Continuous passive motion (CPM) with maximal force

Correct Answer & Explanation

. Early controlled range of motion exercises (flexion, extension, pronation, supination) as tolerated

Explanation

After stable ORIF of an adult Monteggia fracture, the most important component of the rehabilitation protocol is early controlled range of motion exercises. Stable fixation of the ulna typically allows for judicious initiation of flexion, extension, pronation, and supination exercises as tolerated by the patient and dictated by the surgeon's confidence in the stability of the fixation. This helps prevent stiffness, which is a common and debilitating complication of elbow trauma. Strict immobilization can lead to severe stiffness. Aggressive strengthening or weight-bearing is too early, and CPM should be controlled, not maximal force.

Question 9650

Topic: 2. Trauma
What is the typical radiographic appearance of a Monteggia Type I fracture in an adult?
. Posterior dislocation of the radial head with a comminuted olecranon fracture.
. Anterior dislocation of the radial head with an anteriorly angulated fracture of the ulnar diaphysis.
. Lateral dislocation of the radial head with a distal ulnar metaphyseal fracture.
. Fracture of both radius and ulna shafts with anterior radial head dislocation.
. Radial head fracture with intact ulna.

Correct Answer & Explanation

. Anterior dislocation of the radial head with an anteriorly angulated fracture of the ulnar diaphysis.

Explanation

A Bado Type I Monteggia fracture (the most common type) is characterized by an anterior dislocation of the radial head and an anteriorly angulated fracture of the ulnar diaphysis. The apex of the ulnar fracture deformity points anteriorly, aligning with the anterior displacement of the radial head. The other options describe Type II, Type III, Type IV, or other injuries.

Question 9651

Topic: 2. Trauma

Which of the following is an early sign of a developing compartment syndrome in a patient with an acutely treated Monteggia fracture?

. Severe bruising around the elbow
. Swelling and warmth of the forearm
. Paresthesia distal to the injury
. Pain out of proportion to the injury, especially with passive stretching of muscles
. Inability to actively move fingers

Correct Answer & Explanation

. Pain out of proportion to the injury, especially with passive stretching of muscles

Explanation

Compartment syndrome is a serious, limb-threatening complication. The cardinal sign (and often the earliest and most reliable) of acute compartment syndrome in the forearm is pain out of proportion to the injury or expected post-operative pain, especially exacerbated by passive stretching of the fingers (e.g., passive extension of digits for forearm flexor compartment involvement). While swelling, paresthesia, and inability to move fingers can be signs, 'pain out of proportion' is the classic hallmark. Bruising and warmth are general signs of inflammation and injury but not specific to compartment syndrome development.

Question 9652

Topic: 2. Trauma

A 70-year-old patient with osteoporosis sustains a Monteggia Type I fracture. What additional consideration might influence surgical management compared to a younger adult?

. Shorter immobilization period due to faster bone healing.
. Higher likelihood of delayed union or nonunion requiring a longer or more robust plate construct.
. Exclusive use of external fixation due to poor bone quality.
. Radial head excision is preferred due to poor healing potential.
. No specific differences; standard adult treatment applies.

Correct Answer & Explanation

. Higher likelihood of delayed union or nonunion requiring a longer or more robust plate construct.

Explanation

In osteoporotic patients, bone quality is diminished, increasing the risk of comminution, implant pull-out, and delayed union or nonunion. Therefore, for an elderly patient with a Monteggia fracture, surgical management might involve a more robust plate construct (e.g., locking plate for better screw purchase), careful bone handling, and potentially bone grafting. The goal remains anatomical reduction and stable fixation, but the choice of implant and surgical technique may need to be adapted to the compromised bone quality. Shorter immobilization is incorrect, external fixation is not standard, and radial head excision is not a primary treatment choice for acute Monteggia in any age group. There are specific differences related to bone quality in the elderly.

Question 9653

Topic: 2. Trauma
Which of the following describes the Bado and Peril Type most likely to occur in high-energy trauma, often involving a direct blow to the elbow?
. Type I
. Type II
. Type III
. Type IV
. Monteggia equivalent with radial head fracture

Correct Answer & Explanation

. Type II

Explanation

Bado Type II Monteggia fractures, characterized by posterior dislocation of the radial head and a posteriorly angulated ulnar shaft fracture, are often associated with high-energy trauma, such as a direct blow to the posterior aspect of the elbow or a fall on a partially flexed elbow. These mechanisms tend to drive the radial head posteriorly. Type I is more common from a fall on an outstretched hand with hyperpronation, Type III in children, and Type IV is also high energy but with unique combined shaft fractures.

Question 9654

Topic: 2. Trauma

After successful surgical management of an adult Monteggia fracture, the patient complains of persistent painful clicking and grinding during forearm rotation. What complication should be considered?

. Ulnar nonunion
. Heterotopic ossification
. Posterior interosseous nerve palsy
. Distal radioulnar joint instability
. Median nerve entrapment

Correct Answer & Explanation

. Heterotopic ossification

Explanation

Persistent painful clicking and grinding during forearm rotation after elbow trauma and surgery, in the absence of obvious instability, is highly suggestive of heterotopic ossification (HO). HO is the formation of mature lamellar bone in soft tissues where bone does not normally exist, and it is a common complication after elbow trauma, particularly involving the Monteggia injury. The HO can mechanically block motion and cause crepitus. Ulnar nonunion would cause pain and instability but less typically clicking/grinding with rotation alone. Nerve palsy is a sensory/motor deficit. DRUJ instability is a wrist issue. Median nerve entrapment is neuropathic pain.

Question 9655

Topic: 2. Trauma

What percentage of Monteggia fractures are typically Bado Type I?

. 10-20%
. 25-35%
. 40-50%
. 60-70%
. 80-90%

Correct Answer & Explanation

. 60-70%

Explanation

Bado Type I Monteggia fractures are the most common type, accounting for approximately 60-70% of all Monteggia injuries. This type involves an anterior dislocation of the radial head with an anteriorly angulated ulnar shaft fracture. It is essential to recognize its prevalence and characteristics for appropriate diagnosis and management.

Question 9656

Topic: 2. Trauma

A 6-year-old child presents with a Monteggia Type I fracture. After successful closed reduction, what is the minimum duration for cast immobilization?

. 2 weeks
. 3 weeks
. 4 weeks
. 6 weeks
. 8 weeks

Correct Answer & Explanation

. 6 weeks

Explanation

For pediatric Monteggia fractures that are successfully reduced by closed means, a minimum of 6 weeks of immobilization in a long-arm cast is generally recommended. This allows sufficient time for the ulnar fracture to heal and for the stretched or partially torn annular ligament to heal and regain its stability, preventing redislocation of the radial head. Shorter periods carry a higher risk of redislocation. Depending on the specific injury and patient, immobilization may sometimes extend to 8 weeks, but 6 weeks is the common minimum.

Question 9657

Topic: 2. Trauma

What is the primary diagnostic pitfall in Monteggia fractures, leading to delayed or missed diagnosis?

. Failure to obtain radiographs of the entire forearm.
. Over-reliance on clinical examination without imaging.
. Missing the radial head dislocation by focusing solely on the ulnar fracture.
. Misinterpreting a normal fat pad sign as pathology.
. Incorrectly identifying the type of ulnar fracture.

Correct Answer & Explanation

. Missing the radial head dislocation by focusing solely on the ulnar fracture.

Explanation

The most common and critical diagnostic pitfall in Monteggia fractures is missing the radial head dislocation. Emergency room personnel and even experienced clinicians can focus solely on the obvious ulnar fracture, especially if it's displaced, and overlook the subtle signs of radial head dislocation on radiographs. It is paramount to always assess the radiocapitellar articulation carefully on all elbow views, even if the primary ulnar fracture appears straightforward. Failure to obtain full forearm views also contributes to missed diagnoses, but specifically missing the radial head is the core error.

Question 9658

Topic: 2. Trauma

Which of the following statements about the annular ligament in Monteggia fractures is true?

. It is always completely ruptured in all Monteggia fractures.
. It is rarely involved in pediatric Monteggia fractures.
. Its integrity or repair is crucial for maintaining radial head stability after reduction.
. It is a minor ligament with little biomechanical significance.
. It primarily restricts elbow flexion and extension.

Correct Answer & Explanation

. Its integrity or repair is crucial for maintaining radial head stability after reduction.

Explanation

The annular ligament encircles the radial head, forming part of the proximal radioulnar joint capsule and providing stability against radial head displacement. In Monteggia fractures, the annular ligament is almost always injuredโ€”either stretched, partially torn, or completely ruptured. Its integrity, or its successful repair or reconstruction in chronic cases, is absolutely crucial for maintaining the concentric reduction and stability of the radial head after the ulnar fracture has been addressed. It is not always completely ruptured, is commonly involved in pediatric cases, and is a major stabilizer for forearm rotation, not primary elbow flexion/extension.

Question 9659

Topic: 2. Trauma

Which specific complication is associated with a Monteggia equivalent injury where there is an ulnar shaft fracture and an ipsilateral distal radial fracture (a variant of Type IV)?

. Isolated radial head necrosis
. Interosseous membrane integrity is almost always preserved
. Risk of forearm compartment syndrome is lower than isolated ulna fractures
. High incidence of malunion or nonunion of both forearm bones if not adequately fixed
. No impact on forearm rotation if treated conservatively

Correct Answer & Explanation

. High incidence of malunion or nonunion of both forearm bones if not adequately fixed

Explanation

A Monteggia equivalent with an ulnar shaft fracture and an ipsilateral distal radial fracture (a severe variant often termed Type IV if radial head is dislocated anteriorly, or a combination injury) involves significant disruption of the entire forearm. Fractures of both forearm bones, especially diaphyseal, carry a high risk of malunion or nonunion if not anatomically reduced and stably fixed. This risk is compounded by the associated joint dislocations. The interosseous membrane is often severely disrupted. Compartment syndrome risk is elevated. Conservative treatment for such severe injuries would almost certainly lead to poor outcomes, including loss of rotation and malunion/nonunion.

Question 9660

Topic: 2. Trauma

A patient sustained a Monteggia Type I fracture with an associated radial head fracture. What is the preferred treatment approach?

. Closed reduction of the radial head, cast immobilization, and observe the radial head fracture.
. Excision of the radial head as it's typically highly comminuted.
. ORIF of the ulnar fracture, concurrent open reduction and internal fixation or excision/replacement of the radial head fracture as indicated.
. External fixation for both fractures.
. Arthroplasty of the elbow.

Correct Answer & Explanation

. ORIF of the ulnar fracture, concurrent open reduction and internal fixation or excision/replacement of the radial head fracture as indicated.

Explanation

When a Monteggia Type I fracture is combined with a radial head fracture (a Monteggia equivalent), the treatment must address both components. ORIF of the ulnar fracture is paramount. Concurrently, the radial head fracture must be managed based on its type and displacement. This can involve open reduction and internal fixation of the radial head (if amenable), radial head excision (for highly comminuted fractures not suitable for fixation, typically in adults), or radial head replacement (arthroplasty) for more severe cases to maintain forearm length and stability. Closed reduction alone is insufficient. External fixation and total elbow arthroplasty are not primary treatments for this specific injury pattern.

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