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Elbow & Forearm MCQs

Practice Set 24 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 461

Topic: Elbow & Forearm

A 25-year-old male sustains an Essex-Lopresti injury characterized by a comminuted radial head fracture, DRUJ dislocation, and interosseous membrane disruption. The radial head is deemed unsalvageable. Radial head excision without replacement is contraindicated in this setting due to the risk of which of the following?

. Proximal migration of the radius and ulnocarpal impaction
. Posterolateral rotatory instability (PLRI) of the elbow
. Heterotopic ossification of the interosseous membrane (synostosis)
. Ulnar nerve entrapment at the cubital tunnel
. Avascular necrosis of the scaphoid

Correct Answer & Explanation

. Proximal migration of the radius and ulnocarpal impaction

Explanation

An Essex-Lopresti injury disrupts the longitudinal radioulnar axis. The radial head is a crucial secondary stabilizer against proximal translation of the radius. If the radial head is excised without prosthetic replacement when the interosseous membrane is torn, the radius will migrate proximally, leading to severe DRUJ incongruity, distal ulna abutment against the carpus (ulnocarpal impaction), and profound wrist pain/dysfunction. A radial head arthroplasty is mandatory.

Question 462

Topic: Elbow & Forearm

During a single-incision anterior approach for a distal biceps tendon repair, excessive lateral retraction is applied to expose the radial tuberosity. Postoperatively, the patient complains of numbness and paresthesias along the lateral aspect of their volar forearm. Which nerve was most likely injured?

. Superficial radial nerve
. Posterior interosseous nerve (PIN)
. Lateral antebrachial cutaneous nerve (LABCN)
. Medial antebrachial cutaneous nerve (MABCN)
. Palmar cutaneous branch of the median nerve

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve (LABCN)

Explanation

The Lateral Antebrachial Cutaneous Nerve (LABCN), a continuation of the musculocutaneous nerve, exits between the biceps and brachialis and runs laterally in the distal arm and proximal forearm. It is highly susceptible to stretch or transection during the anterior single-incision approach to the distal biceps, particularly with overzealous lateral retraction. It provides sensation to the lateral aspect of the volar forearm.

Question 463

Topic: Elbow & Forearm

A patient presents with a coronal shear fracture of the distal humerus involving the capitellum and the lateral ridge of the trochlea. According to the Dubberley classification, what specific radiographic feature defines the suffix 'B' in this injury?

. Extension into the medial epicondyle
. Concomitant radial head fracture
. Posterior condylar comminution
. Lateral collateral ligament avulsion
. Anterior cortical impaction

Correct Answer & Explanation

. Posterior condylar comminution

Explanation

In the Dubberley classification of capitellar fractures, Type 1 involves the capitellum, Type 2 involves the capitellum and trochlea, and Type 3 is comminuted. The suffix 'A' indicates an intact posterior condyle, while 'B' indicates posterior condylar comminution, which often necessitates posterior supplemental fixation.

Question 464

Topic: Elbow & Forearm

A 35-year-old female sustains a highly comminuted capitellum and trochlea fracture extending into the posterior column (Dubberley Type 3B). Which surgical approach provides the most optimal exposure for bicolumnar fixation of this specific injury pattern?

. Extended lateral approach (Kocher interval)
. Universal posterior approach with olecranon osteotomy
. Anterolateral approach
. Medial over-the-top approach
. Extensile volar approach

Correct Answer & Explanation

. Universal posterior approach with olecranon osteotomy

Explanation

While an extended lateral approach is common for isolated capitellar fractures, Dubberley Type 3 fractures involving both the capitellum and trochlea with posterior comminution often require a posterior approach with an olecranon osteotomy for adequate visualization and stable bicolumnar fixation.

Question 465

Topic: Elbow & Forearm

A 40-year-old male falls from a height and sustains a comminuted, unsalvageable radial head fracture. During examination, he reports severe pain at the ipsilateral wrist, and the distal radioulnar joint (DRUJ) is grossly unstable. What is the most appropriate management?

. Radial head excision alone
. Radial head arthroplasty, pinning of the DRUJ, and immobilization in supination
. Radial head excision and ulnar shortening osteotomy
. Open reduction internal fixation of the radial head despite comminution
. Silicone radial head replacement and early mobilization

Correct Answer & Explanation

. Radial head arthroplasty, pinning of the DRUJ, and immobilization in supination

Explanation

This patient has an Essex-Lopresti injury, consisting of a radial head fracture, interosseous membrane tear, and DRUJ disruption. Radial head excision is contraindicated as it leads to proximal radial migration; treatment requires rigid radial head arthroplasty and DRUJ stabilization.

Question 466

Topic: Elbow & Forearm

A surgeon is planning a distal biceps tendon repair using a two-incision technique (modified Boyd-Anderson). Which complication is specifically increased with the two-incision technique compared to a single anterior incision approach?

. Lateral antebrachial cutaneous nerve neuropraxia
. Radial nerve transection
. Heterotopic ossification (radioulnar synostosis)
. Posterior interosseous nerve injury
. Rerupture of the biceps tendon

Correct Answer & Explanation

. Heterotopic ossification (radioulnar synostosis)

Explanation

The two-incision technique was historically associated with a higher risk of radioulnar synostosis, especially if the interosseous membrane is violated or muscle planes are not respected. The single-incision technique carries a higher risk of lateral antebrachial cutaneous nerve (LABC) injury.

Question 467

Topic: Elbow & Forearm

What is the recommended sequence of surgical reconstruction for a "terrible triad" injury of the elbow?

. MCL repair, LCL repair, radial head, coronoid
. Coronoid, radial head, LCL repair
. Radial head, coronoid, MCL repair
. LCL repair, coronoid, radial head, MCL repair
. Radial head, LCL repair, coronoid

Correct Answer & Explanation

. Coronoid, radial head, LCL repair

Explanation

The standard surgical sequence for a terrible triad injury of the elbow (radial head fracture, coronoid fracture, and elbow dislocation) is fixation of the coronoid, followed by the radial head, and finally repair of the lateral collateral ligament (LCL).

Question 468

Topic: Elbow & Forearm
A 40-year-old female presents with a displaced fracture of the capitellum that includes the lateral trochlear ridge. According to the Bryan and Morrey classification, what type of fracture is this, and what is the preferred treatment?
. Type I; closed reduction and casting
. Type II; fragment excision
. Type III; nonoperative management
. Type IV; open reduction and internal fixation
. Type I; open reduction and internal fixation

Correct Answer & Explanation

. Type IV; open reduction and internal fixation

Explanation

A Type IV Bryan and Morrey capitellum fracture involves the capitellum and extends medially to include the lateral trochlear ridge. Open reduction and internal fixation is indicated to restore joint congruity and elbow stability.

Question 469

Topic: Elbow & Forearm

A 38-year-old female falls on an outstretched hand and sustains a comminuted radial head fracture. On examination, she complains of severe wrist pain and has tenderness over the distal radioulnar joint (DRUJ). Which of the following treatments is contraindicated?

. Open reduction and internal fixation of the radial head
. Radial head arthroplasty
. Radial head excision alone
. Closed reduction and casting of the forearm
. Fixation of the radial head with DRUJ pinning

Correct Answer & Explanation

. Radial head arthroplasty

Explanation

The patient has an Essex-Lopresti injury, characterized by a radial head fracture, interosseous membrane disruption, and DRUJ dislocation. Radial head excision alone is contraindicated as it will lead to proximal migration of the radius and chronic wrist pain.

Question 470

Topic: Elbow & Forearm

A 35-year-old female presents with a highly comminuted distal humerus fracture after a fall. Imaging identifies a type IV capitellum fracture according to the McKee modification of the Bryan and Morrey classification. What specific finding defines this fracture type?

. Pure articular cartilage shear fracture without subchondral bone
. Comminuted fracture strictly isolated to the capitellar articular surface
. Coronal shear fracture extending laterally to the epicondyle
. Large osseous piece of the capitellum without any trochlear involvement
. Coronal shear fracture involving the capitellum and the majority of the trochlea

Correct Answer & Explanation

. Coronal shear fracture involving the capitellum and the majority of the trochlea

Explanation

A Type IV capitellum fracture involves a coronal shear fracture that propagates medially to include the capitellum and a large portion of the trochlea. This often produces the classic 'double-arc sign' on a lateral radiograph.

Question 471

Topic: Elbow & Forearm

When comparing the single anterior incision to the two-incision technique for distal biceps tendon repair, the single anterior incision is associated with a higher risk of injury to which of the following nerves?

. Posterior interosseous nerve (PIN)
. Lateral antebrachial cutaneous nerve (LABCN)
. Superficial radial nerve
. Ulnar nerve
. Anterior interosseous nerve (AIN)

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve (LABCN)

Explanation

The single-incision anterior approach for distal biceps repair is associated with a higher risk of neurapraxia to the lateral antebrachial cutaneous nerve (LABCN), which is often retracted laterally during the exposure. The two-incision technique historically carries a higher risk of heterotopic ossification and potential injury to the posterior interosseous nerve (PIN) during the posterior exposure if the forearm is not fully pronated.

Question 472

Topic: Elbow & Forearm
A 35-year-old female sustains a coronal shear fracture of the distal humerus. Intraoperative findings reveal the fracture involves the capitellum and the lateral half of the trochlea as a single articular piece. Which classification best describes this specific fracture pattern?
. Bryan and Morrey Type I (Hahn-Steinthal)
. Bryan and Morrey Type II (Kocher-Lorenz)
. Bryan and Morrey Type III (Brogdon)
. Bryan and Morrey Type IV (McKee modification)
. Jupiter Type I

Correct Answer & Explanation

. Bryan and Morrey Type IV (McKee modification)

Explanation

The McKee modification to the Bryan and Morrey classification added the Type IV fracture, which describes a coronal shear fracture involving the capitellum and a large portion of the lateral trochlea as a single fragment. Type I is a large osseous capitellum fragment (Hahn-Steinthal), Type II is a thin articular cartilage fragment with minimal bone (Kocher-Lorenz), and Type III is a comminuted capitellum fracture.

Question 473

Topic: Elbow & Forearm

A 40-year-old bodybuilder undergoes a distal biceps tendon repair utilizing a two-incision technique. Compared to a single-incision anterior approach, the two-incision technique carries a uniquely higher risk of which of the following complications?

. Posterior interosseous nerve (PIN) neurapraxia
. Lateral antebrachial cutaneous nerve (LABCN) neurapraxia
. Radioulnar synostosis (heterotopic ossification)
. Recurrent tendon rupture
. Median nerve entrapment

Correct Answer & Explanation

. Radioulnar synostosis (heterotopic ossification)

Explanation

Historically and in comparative studies, the two-incision technique for distal biceps repair has been associated with a higher risk of radioulnar synostosis (heterotopic ossification) because of the subperiosteal dissection near the ulna. Conversely, the single-incision anterior approach places the lateral antebrachial cutaneous nerve (LABCN) and the posterior interosseous nerve (PIN) at higher risk.

Question 474

Topic: Elbow & Forearm

A 35-year-old male requires ligamentous reconstruction for chronic posterolateral rotatory instability (PLRI) of the elbow. During reconstruction of the lateral ulnar collateral ligament (LUCL), where should the femoral tunnel be placed to best approximate the isometric point of the native ligament?

. At the center of the capitellum
. Directly on the lateral epicondyle
. Posterior and superior to the lateral epicondyle
. Anterior and inferior to the lateral epicondyle
. At the isometric center of rotation on the lateral epicondyle

Correct Answer & Explanation

. At the isometric center of rotation on the lateral epicondyle

Explanation

The isometric point for the origin of the lateral ulnar collateral ligament (LUCL) is located at the isometric center of rotation of the capitellum, which corresponds anatomically to the lateral epicondyle. Improper placement, particularly anterior to the axis of rotation, results in the graft being tight in flexion and loose in extension, leading to recurrent instability or loss of motion.

Question 475

Topic: Elbow & Forearm

A 40-year-old female sustains a fall on an outstretched hand and incurs a complex coronal shear fracture of the distal humerus involving the capitellum and trochlea. Based on the Dubberley classification, what defines a Type 3 capitellum fracture?

. Involvement of the capitellum only
. Involvement of the capitellum and the lateral trochlear ridge
. Fracture extending to the medial epicondyle
. Comminution of the posterior aspect of the lateral condyle
. Fracture extending across the capitellum and the entire trochlea

Correct Answer & Explanation

. Involvement of the capitellum and the lateral trochlear ridge

Explanation

In the Dubberley classification of coronal shear fractures of the distal humerus: Type 1 involves the capitellum with or without the lateral trochlear ridge. Type 2 involves the capitellum and extends medially into the trochlea in a single piece. Type 3 involves fractures extending across the capitellum and the entire trochlea (communited or separate fragments). The addition of 'A' means the posterior condyle is intact, and 'B' means there is posterior condylar comminution.

Question 476

Topic: Elbow & Forearm

A 45-year-old weightlifter feels a pop in the posterior aspect of his elbow during a heavy bench press. Which of the following physical examination findings is most specific for a complete acute distal triceps tendon rupture?

. Inability to passively extend the elbow
. Loss of active elbow extension against gravity
. Palpable gap in the extensor carpi radialis brevis
. Positive Hook test
. Severe pain with resisted forearm supination

Correct Answer & Explanation

. Loss of active elbow extension against gravity

Explanation

A complete distal triceps rupture typically presents with an inability to actively extend the elbow against gravity (often tested with the arm abducted to 90 degrees). A palpable gap may be felt proximal to the olecranon. The Hook test is used for distal biceps ruptures. Pain with resisted supination is also associated with biceps pathology or lateral epicondylitis.

Question 477

Topic: Elbow & Forearm

A 35-year-old male falls on an outstretched hand and sustains a fracture of the anteromedial facet of the coronoid process. Which of the following injury mechanisms and associated ligamentous injuries is most classically associated with this fracture pattern?

. Posterolateral rotatory instability with lateral ulnar collateral ligament (LUCL) tear
. Varus posteromedial rotatory instability with lateral ulnar collateral ligament (LUCL) tear
. Valgus overload with medial ulnar collateral ligament (MUCL) anterior bundle tear
. Axial compression with radial head fracture and interosseous membrane tear
. Posterior dislocation with complete anterior capsule avulsion

Correct Answer & Explanation

. Varus posteromedial rotatory instability with lateral ulnar collateral ligament (LUCL) tear

Explanation

Fractures of the anteromedial facet of the coronoid process are the hallmark of varus posteromedial rotatory instability (VPMRI) of the elbow. The mechanism involves an axial load combined with varus and posteromedial rotatory forces. This causes the anteromedial coronoid facet to impact the medial trochlea, resulting in a fracture, and invariably causes rupture of the lateral collateral ligament (LCL) complex, including the LUCL. Failure to recognize and treat the LUCL injury and the facet fracture can lead to rapid post-traumatic arthrosis and chronic subluxation.

Question 478

Topic: Elbow & Forearm

A patient demonstrates posterolateral rotatory instability (PLRI) of the elbow. The primary pathomechanical lesion involves the avulsion of the lateral ulnar collateral ligament (LUCL) from which specific anatomic structure?

. Coronoid process
. Radial head
. Lateral epicondyle of the humerus
. Supinator crest of the ulna
. Olecranon tip

Correct Answer & Explanation

. Lateral epicondyle of the humerus

Explanation

Posterolateral rotatory instability (PLRI) of the elbow is primarily caused by an insufficiency of the lateral ulnar collateral ligament (LUCL). The LUCL originates on the lateral epicondyle of the humerus and inserts on the supinator crest of the ulna. The most common site of avulsion or disruption resulting in PLRI is at its humeral origin on the lateral epicondyle.

Question 479

Topic: Elbow & Forearm
A 42-year-old female falls onto an outstretched hand and sustains an elbow fracture. The lateral radiograph demonstrates a 'double-arc' sign. According to the Bryan and Morrey classification modified by McKee, what does this radiographic sign pathognomonically represent?
. A Type I (Hahn-Steinthal) fracture with isolated large osseous capitellum fragment
. A Type II (Kocher-Lorenz) cartilaginous shear fracture
. A Type III comminuted capitellum fracture
. A Type IV fracture involving the capitellum and extending medially to include the lateral trochlear ridge
. Associated posterior dislocation of the radial head

Correct Answer & Explanation

. A Type IV fracture involving the capitellum and extending medially to include the lateral trochlear ridge

Explanation

The 'double-arc' sign on a lateral elbow radiograph is pathognomonic for a McKee modification Type IV coronal shear fracture. The two arcs represent the subchondral bone of the capitellum and the lateral ridge of the trochlea, which are fractured and displaced as a single unit. It is critical to recognize this, as it indicates a more extensive medial extension of the fracture that requires adequate surgical exposure and fixation to restore the radiocapitellar and ulnohumeral articulations.

Question 480

Topic: Elbow & Forearm

Following an ulnar collateral ligament (UCL) reconstruction ('Tommy John' surgery) using a palmaris longus autograft via the docking technique, what is the most frequent postoperative complication reported in the literature?

. Palmaris longus graft rupture
. Medial epicondyle avulsion fracture
. Ulnar neuropathy
. Superficial wound infection
. Heterotopic ossification of the medial collateral ligament

Correct Answer & Explanation

. Ulnar neuropathy

Explanation

Ulnar neuropathy is the most common complication following UCL reconstruction, reported in approximately 5-10% of cases. The ulnar nerve lies in the cubital tunnel immediately posterior to the UCL and is at high risk of irritation, traction, or compression during surgical exposure and tunnel drilling. Modern techniques, such as the docking technique with meticulous handling of the nerve or formal transposition when indicated, have helped minimize, but not eliminate, this risk.

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