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Elbow & Forearm MCQs

Practice Set 6 of 57

This practice set contains high-yield board review questions covering key concepts in Elbow & Forearm. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 101

Topic: Elbow & Forearm

A 6-year-old child presents with a Bado Type I Monteggia equivalent lesion featuring a plastic deformation of the ulna and an anterior radial head dislocation. What is the most appropriate initial management?

. Open reduction of the radial head and annular ligament reconstruction
. Closed reduction of the radial head with cast immobilization in extension
. Closed reduction of the radial head with application of corrective bending force to the ulna
. Intramedullary nailing of the radius and ulna
. Plate fixation of the ulna without radial head reduction

Correct Answer & Explanation

. Closed reduction of the radial head with application of corrective bending force to the ulna

Explanation

In pediatric Monteggia equivalents with ulnar plastic deformation, it is critical to correct the bowing of the ulna. Applying a corrective bending force to the ulna restores length and alignment, allowing the radial head to spontaneously reduce and remain stable.

Question 102

Topic: Elbow & Forearm

Which of the following physical examination tests is considered most accurate for intraoperative evaluation of syndesmotic instability following internal fixation of a lateral malleolus fracture?

. Squeeze test
. External rotation stress test (Kleiger test)
. Cotton test (lateral hook test)
. Anterior drawer test
. Talar tilt test

Correct Answer & Explanation

. Cotton test (lateral hook test)

Explanation

The Cotton test (lateral pull on the fibula with a bone hook) is considered the most reliable intraoperative test for assessing syndesmotic instability after the fibula fracture has been provisionally or definitively fixed.

Question 103

Topic: Elbow & Forearm

A 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) vascularized bone graft is utilized for a scaphoid nonunion. Between which two tendons is this pedicle identified?

. Abductor pollicis longus and extensor pollicis brevis
. Extensor pollicis brevis and extensor carpi radialis longus
. Extensor carpi radialis brevis and extensor pollicis longus
. Extensor pollicis longus and extensor digitorum communis
. Extensor digitorum communis and extensor digiti minimi

Correct Answer & Explanation

. Abductor pollicis longus and extensor pollicis brevis

Explanation

The 1,2 ICSRA lies on the surface of the extensor retinaculum between the first dorsal compartment (APL, EPB) and the second dorsal compartment (ECRL, ECRB).

Question 104

Topic: Elbow & Forearm
A 62-year-old female presents with a Mason-Johnston Type II radial head fracture with 2mm displacement and a palpable block to terminal forearm pronation. There is no associated elbow dislocation or other obvious ligamentous injury. What is the most appropriate initial management strategy?
. Sling immobilization for 3 weeks followed by physiotherapy
. Open reduction and internal fixation (ORIF)
. Radial head excision
. Radial head replacement
. Attempt closed reduction under local anesthetic

Correct Answer & Explanation

. Open reduction and internal fixation (ORIF)

Explanation

A Mason-Johnston Type II fracture with a mechanical block to forearm rotation is a strong indication for surgical intervention, typically ORIF. The mechanical block signifies impingement of the displaced fragment, which will prevent full range of motion and lead to chronic dysfunction if not addressed.

Question 105

Topic: Elbow & Forearm
A 55-year-old painter presents with a Mason-Johnston Type III radial head fracture with 4 fragments, involving 60% of the articular surface. He is very active and desires a full return to function. There is no associated elbow dislocation. What is the preferred surgical option to restore function and stability?
. Open reduction and internal fixation (ORIF) with headless screws
. Radial head excision
. Radial head replacement
. Primary arthrodesis of the elbow
. Non-operative management with early motion

Correct Answer & Explanation

. Radial head replacement

Explanation

For highly comminuted (Mason-Johnston Type III or IV) radial head fractures, particularly in active patients where restoration of articular congruity and preservation of radial length are critical, radial head replacement is often the preferred surgical option.

Question 106

Topic: Elbow & Forearm

A 40-year-old male sustained a mid-shaft humerus fracture with an associated high radial nerve palsy. After 6 months of observation and serial EMG testing, there is no clinical or electrical evidence of reinnervation. To restore strong, central wrist extension, what is the most common and reliable tendon transfer performed?

. Pronator teres (PT) to Extensor Carpi Radialis Brevis (ECRB)
. Flexor Carpi Ulnaris (FCU) to Extensor Digitorum Communis (EDC)
. Flexor Carpi Radialis (FCR) to Extensor Pollicis Longus (EPL)
. Palmaris Longus (PL) to Extensor Carpi Radialis Longus (ECRL)
. Flexor Digitorum Superficialis (FDS) to Extensor Indicis Proprius (EIP)

Correct Answer & Explanation

. Pronator teres (PT) to Extensor Carpi Radialis Brevis (ECRB)

Explanation

For radial nerve palsy, the Pronator Teres (PT) is most commonly transferred to the Extensor Carpi Radialis Brevis (ECRB) to restore strong, centralized wrist extension. Transfer to the ECRL is typically avoided as it leads to excessive radial deviation.

Question 107

Topic: Elbow & Forearm

When surgically managing a "terrible triad" injury of the elbow, a systematic approach to repair is required to restore stability. According to standard protocols, what is the generally recommended sequence of repair from deep to superficial?

. Coronoid, radial head, lateral collateral ligament (LCL)
. Lateral collateral ligament (LCL), radial head, coronoid
. Radial head, coronoid, lateral collateral ligament (LCL)
. Medial collateral ligament (MCL), coronoid, radial head
. Radial head, lateral collateral ligament (LCL), coronoid

Correct Answer & Explanation

. Coronoid, radial head, lateral collateral ligament (LCL)

Explanation

The standard surgical approach for a terrible triad injury builds stability from inside out (deep to superficial). The sequence is fixation of the coronoid fracture, followed by radial head repair or replacement, and finally repair of the lateral collateral ligament (LCL) complex.

Question 108

Topic: Elbow & Forearm

A 48-year-old male presents to the emergency department after a fall onto an outstretched hand. Radiographs reveal an elbow dislocation, a comminuted radial head fracture, and a coronoid fracture. This constellation of injuries is consistent with a 'terrible triad' of the elbow. Given the inherent instability of this injury, which of the following statements best describes the primary mechanism of posterolateral rotatory instability (PLRI) in this context?

. A. Disruption of the anterior bundle of the medial collateral ligament (MCL).
. B. Avulsion of the common flexor origin from the medial epicondyle.
. C. Failure of the lateral ulnar collateral ligament (LUCL) component of the lateral collateral ligament (LCL) complex.
. D. Impingement of the olecranon in the olecranon fossa.
. E. Isolated rupture of the annular ligament.

Correct Answer & Explanation

. C. Failure of the lateral ulnar collateral ligament (LUCL) component of the lateral collateral ligament (LCL) complex.

Explanation

Correct Answer: CThe terrible triad injury involves an elbow dislocation, radial head fracture, and coronoid fracture. The inherent instability, particularly posterolateral rotatory instability (PLRI), is primarily due to the failure of the lateral ulnar collateral ligament (LUCL) component of the lateral collateral ligament (LCL) complex. The LUCL is the primary static stabilizer against varus stress and posterolateral rotatory forces. Its disruption allows the ulna to externally rotate off the trochlea, leading to the characteristic PLRI pattern.Option A (Disruption of the anterior bundle of the medial collateral ligament (MCL))is incorrect. While the MCL can be injured in terrible triads, its primary role is to resist valgus stress. Its disruption leads to valgus instability, not the primary posterolateral rotatory instability seen with LCL failure.Option B (Avulsion of the common flexor origin from the medial epicondyle)is incorrect. This injury is associated with medial epicondyle fractures or severe valgus stress injuries but is not the primary mechanism for PLRI.Option D (Impingement of the olecranon in the olecranon fossa)is incorrect. Olecranon impingement can occur in extension but is not the primary mechanism of instability in a terrible triad, which is characterized by ligamentous disruption.Option E (Isolated rupture of the annular ligament)is incorrect. While the annular ligament stabilizes the radial head, its isolated rupture does not cause the global instability and posterolateral rotation characteristic of a terrible triad. The LUCL is the key stabilizer against PLRI.

Question 109

Topic: Elbow & Forearm

During the radial head replacement portion of a terrible triad repair, the surgeon must be meticulous to avoid 'overstuffing' the joint. What is the most significant biomechanical consequence of overstuffing the radiocapitellar joint with a radial head prosthesis?

. A. Increased risk of ulnar nerve compression.
. B. Reduced range of motion, particularly pronation and supination.
. C. Increased tension on the medial collateral ligament (MCL), leading to valgus instability.
. D. Premature wear of the capitellum.
. E. Increased tension on the lateral collateral ligament (LCL) complex, potentially leading to recurrent posterolateral rotatory instability.

Correct Answer & Explanation

. E. Increased tension on the lateral collateral ligament (LCL) complex, potentially leading to recurrent posterolateral rotatory instability.

Explanation

Correct Answer: EOverstuffing the radiocapitellar joint with a radial head prosthesis increases the length of the radius relative to the ulna. This leads to increased tension on the lateral collateral ligament (LCL) complex, which can paradoxically cause recurrent posterolateral rotatory instability (PLRI) by preventing proper seating of the ulna on the trochlea and increasing stress on the already compromised LCL. It can also lead to pain and stiffness.Option A (Increased risk of ulnar nerve compression)is incorrect. While ulnar nerve issues can occur with elbow trauma or surgery, overstuffing primarily affects joint mechanics and ligamentous tension, not directly the ulnar nerve.Option B (Reduced range of motion, particularly pronation and supination)is partially correct as overstuffing can lead to stiffness and reduced motion, but the most significant biomechanical consequence related to stability in a terrible triad is the impact on the LCL and PLRI.Option C (Increased tension on the medial collateral ligament (MCL), leading to valgus instability)is incorrect. Overstuffing primarily affects the lateral side of the elbow, increasing tension on the LCL, not the MCL.Option D (Premature wear of the capitellum)is incorrect. While improper sizing could theoretically lead to abnormal contact pressures, the primary and more immediate concern with overstuffing is the effect on joint stability and ligamentous tension, particularly the LCL.

Question 110

Topic: Elbow & Forearm

A 35-year-old construction worker sustains a terrible triad injury. During the operative repair, after addressing the radial head and coronoid, the surgeon proceeds to repair the lateral collateral ligament (LCL) complex. Which specific component of the LCL complex is most critical to repair to restore stability and prevent recurrent posterolateral rotatory instability (PLRI)?

. A. Radial collateral ligament (RCL).
. B. Annular ligament.
. C. Accessory lateral collateral ligament (ALCL).
. D. Lateral ulnar collateral ligament (LUCL).
. E. Anterior bundle of the medial collateral ligament (MCL).

Correct Answer & Explanation

. D. Lateral ulnar collateral ligament (LUCL).

Explanation

Correct Answer: DThe lateral ulnar collateral ligament (LUCL) is the primary static stabilizer against posterolateral rotatory instability (PLRI) of the elbow. It originates from the lateral epicondyle and inserts onto the supinator crest of the ulna. Its disruption allows the ulna to externally rotate off the trochlea, leading to the characteristic instability pattern seen in terrible triads. Therefore, its repair is critical for restoring stability.Option A (Radial collateral ligament (RCL))is incorrect. The RCL originates from the lateral epicondyle and blends with the annular ligament. It primarily resists varus stress but is less critical for PLRI than the LUCL.Option B (Annular ligament)is incorrect. The annular ligament encircles the radial head, stabilizing it within the radial notch of the ulna. While important for radial head stability, it is not the primary stabilizer against PLRI.Option C (Accessory lateral collateral ligament (ALCL))is incorrect. The ALCL is a variable component that originates from the lateral epicondyle and inserts onto the supinator crest, deep to the LUCL. While it contributes to stability, the LUCL is considered the primary and most consistent stabilizer against PLRI.Option E (Anterior bundle of the medial collateral ligament (MCL))is incorrect. The MCL is on the medial side of the elbow and is the primary stabilizer against valgus stress. It is not involved in preventing PLRI.

Question 111

Topic: Elbow & Forearm
A 4-year-old presents with a Monteggia Type III fracture. After two gentle attempts at closed reduction under sedation, the radial head remains persistently dislocated laterally, as seen in the image. What is the most appropriate next step?
. Repeat closed reduction under general anesthesia with more forceful manipulation
. Proceed with open reduction and internal fixation (ORIF) of the ulna and open reduction of the radial head
. Immobilize in a long-arm cast and re-evaluate in one week
. Order an MRI to identify soft tissue obstruction
. Perform a radial head excision

Correct Answer & Explanation

. Proceed with open reduction and internal fixation (ORIF) of the ulna and open reduction of the radial head

Explanation

If closed reduction attempts for a pediatric Monteggia fracture are unsuccessful after one or, at most, two gentle attempts, further forceful manipulation is not recommended as it can cause iatrogenic damage. The next step is generally open reduction. The most common cause of irreducible radial head dislocation in children is soft tissue interposition, typically the annular ligament or joint capsule, preventing concentric reduction. Open reduction allows for removal of the obstructing tissue and direct reduction of the radial head, often followed by repair of the annular ligament if necessary, and definitive fixation of the ulnar fracture (which may be a greenstick or plastic deformation). An MRI might confirm soft tissue obstruction but usually is not needed if reduction fails; direct surgical exploration is often more efficient. Radial head excision is not indicated in an acute pediatric setting due to potential growth disturbance and long-term wrist issues.

Question 112

Topic: Elbow & Forearm

When evaluating radiographs for a suspected Monteggia fracture, a critical diagnostic rule involves assessing the alignment of the radial head. As illustrated in the image, what is the most definitive radiographic sign to confirm or rule out a radial head dislocation?

. Widening of the radiocapitellar joint space
. Disruption of the radial head-capitellum alignment on all views
. Presence of fat pads in the elbow joint
. Anterior humeral line not intersecting the capitellum
. Increased carrying angle

Correct Answer & Explanation

. Disruption of the radial head-capitellum alignment on all views

Explanation

Correct Answer: BThe definitive radiographic sign of radial head dislocation is the disruption of the radial head-capitellum alignment on all views (AP, lateral, and obliques if needed). A line drawn through the center of the radial shaft should always pass through the center of the capitellum, regardless of elbow flexion or forearm rotation. If this capitellar-radial head line does not intersect the capitellum, the radial head is dislocated. This 'line of sight' rule is crucial for identifying Monteggia fractures, as subtle radial head dislocations can be easily missed. While fat pads indicate an effusion (suggesting injury), and an abnormal anterior humeral line suggests supracondylar or condylar fractures, only direct visualization of the radiocapitellar relationship confirms dislocation of the radial head. Widening of the joint space can be a sign but is less definitive than complete disruption of alignment.

Question 113

Topic: Elbow & Forearm

A 45-year-old female presents with an elbow dislocation, radial head fracture, and coronoid fracture. What is the recommended sequence of surgical reconstruction for this 'terrible triad' injury?

. LCL repair, radial head fixation/replacement, coronoid fixation
. Coronoid fixation, LCL repair, radial head fixation/replacement
. Coronoid fixation, radial head fixation/replacement, LCL repair
. Radial head fixation/replacement, coronoid fixation, LCL repair
. LCL repair, coronoid fixation, radial head fixation/replacement

Correct Answer & Explanation

. Coronoid fixation, radial head fixation/replacement, LCL repair

Explanation

The standard protocol for terrible triad reconstruction follows an 'inside-out' approach: coronoid fixation first, followed by radial head repair or arthroplasty, and finally lateral collateral ligament (LCL) repair. This sequence systematically restores the anterior buttress, lateral column, and lateral ligamentous stability.

Question 114

Topic: Elbow & Forearm

An 8-year-old boy sustains a Bado Type I Monteggia fracture. After closed reduction and casting of the ulnar shaft, radiographs show the radial head remains dislocated. What is the most common structure blocking closed reduction of the radial head in this scenario?

. Biceps tendon
. Brachialis muscle
. Annular ligament
. Median nerve
. Quadrate ligament

Correct Answer & Explanation

. Annular ligament

Explanation

In pediatric Monteggia injuries, failure to achieve closed reduction of the radial head after anatomically aligning the ulna is most commonly due to interposition of the annular ligament or joint capsule. Open reduction is required to remove the interposed tissue and allow concentric reduction.

Question 115

Topic: Elbow & Forearm

During surgery for a terrible triad injury, the coronoid fracture is identified as an O'Driscoll Type II (anteromedial facet). Which of the following best describes the pathomechanics of this specific coronoid fracture type?

. Varus posteromedial rotational force
. Valgus posterolateral rotational force
. Direct axial load in hyperpronation
. Hyperextension with radial deviation
. Pure anterior shear force

Correct Answer & Explanation

. Varus posteromedial rotational force

Explanation

O'Driscoll anteromedial facet fractures of the coronoid are typically caused by a varus posteromedial rotational force. This mechanism usually disrupts the lateral collateral ligament (LCL) and causes varus instability, distinguishing it from the standard posterolateral rotatory instability (PLRI) mechanism.

Question 116

Topic: Elbow & Forearm

A 42-year-old female sustains a terrible triad injury of the elbow following a fall. During operative management, what is the generally accepted and most mechanically sound sequence of surgical reconstruction?

. Coronoid fixation, lateral ulnar collateral ligament repair, radial head reconstruction
. Radial head reconstruction, coronoid fixation, lateral ulnar collateral ligament repair
. Coronoid fixation, radial head reconstruction, lateral ulnar collateral ligament repair
. Lateral ulnar collateral ligament repair, radial head reconstruction, coronoid fixation
. Coronoid fixation, medial collateral ligament repair, radial head reconstruction

Correct Answer & Explanation

. Coronoid fixation, radial head reconstruction, lateral ulnar collateral ligament repair

Explanation

The standard inside-out surgical sequence for a terrible triad injury involves addressing the deep/medial structures first. Fixation proceeds sequentially with the coronoid (and anterior capsule), followed by the radial head (fixation or arthroplasty), and finally repair of the lateral ulnar collateral ligament (LUCL).

Question 117

Topic: Elbow & Forearm

A 6-year-old boy presents with an isolated anterior radial head dislocation without obvious fracture lines on standard radiographs. To prevent chronic radial head instability, which of the following occult injuries must be meticulously evaluated?

. Plastic deformation of the radius
. Plastic deformation of the ulna
. Distal radioulnar joint disruption
. Lateral ulnar collateral ligament tear
. Coronoid process avulsion

Correct Answer & Explanation

. Plastic deformation of the ulna

Explanation

An isolated radial head dislocation in a child should be treated as a Monteggia equivalent until proven otherwise. Plastic deformation (ulnar bow) of the ulna is the most common occult injury and must be addressed to allow anatomic reduction of the radial head.

Question 118

Topic: Elbow & Forearm

During surgery for a terrible triad injury, the radial head is found to have four highly comminuted articular fragments. Which of the following is the most appropriate management for the radial head to optimize elbow biomechanics and stability?

. Excision of the radial head alone
. Open reduction and internal fixation with a mini-fragment plate
. Radial head arthroplasty
. Excision and delayed radial head reconstruction
. Suture anchor repair of the osteochondral fragments

Correct Answer & Explanation

. Radial head arthroplasty

Explanation

In a terrible triad injury, the radial head is a critical secondary stabilizer to valgus stress. When there are 3 or more fragments making rigid fixation impossible, radial head arthroplasty is indicated to prevent post-operative instability.

Question 119

Topic: Elbow & Forearm

A 35-year-old male sustains a Bado Type I Monteggia fracture. Following rigid internal fixation of the ulnar shaft with a compression plate, the radial head remains persistently anteriorly subluxated. What is the most appropriate next step in management?

. Perform a radial head excision
. Revise the ulnar fixation to restore anatomic length and bow
. Immobilize the arm in forced supination for 6 weeks
. Proceed to primary annular ligament reconstruction
. Perform a radial head arthroplasty

Correct Answer & Explanation

. Revise the ulnar fixation to restore anatomic length and bow

Explanation

In adult Monteggia fractures, persistent subluxation of the radial head after ulnar fixation is almost always due to malreduction of the ulna. The immediate next step is to take down the plate and revise the ulnar fixation to restore perfect length and the anatomic ulnar bow.

Question 120

Topic: Elbow & Forearm

In the setting of a terrible triad injury of the elbow, the lateral ulnar collateral ligament (LUCL) is almost universally disrupted. From which anatomical attachment site is the LUCL most commonly avulsed in this injury pattern?

. The radial head
. The supinator crest of the ulna
. The lateral epicondyle of the humerus
. The coronoid process
. The anterior band of the medial collateral ligament

Correct Answer & Explanation

. The lateral epicondyle of the humerus

Explanation

In terrible triad injuries, the lateral ulnar collateral ligament (LUCL) typically avulses from its humeral origin at the lateral epicondyle. Repair involves reattaching the ligament to the isometric point on the lateral epicondyle using suture anchors.

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