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Elbow & Forearm MCQs

Practice Set 17 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 321

Topic: Elbow & Forearm

A 28-year-old male undergoes surgical treatment for a terrible triad injury. Postoperatively, what forearm position is theoretically most protective of the repaired lateral ulnar collateral ligament (LUCL) during early range of motion exercises?

. Full supination
. Full pronation
. Neutral rotation with varus stress
. Neutral rotation with forced extension
. Supination with valgus stress

Correct Answer & Explanation

. Full pronation

Explanation

Forearm pronation tensions the medial soft tissues and the intact medial hinge, thereby crossing the radius over the ulna and protecting the repaired lateral side (LUCL) from varus stress and subluxation during early rehabilitation.

Question 322

Topic: Elbow & Forearm

You are templating a radial head arthroplasty for an irreparable radial head fracture in a terrible triad injury. What intraoperative landmark is most reliable for determining the correct height of the radial head prosthesis?

. The proximal edge of the lesser sigmoid notch of the ulna
. The distal tip of the coronoid process
. The center of the capitellum
. The insertion of the biceps tendon on the radial tuberosity
. The superior margin of the annular ligament

Correct Answer & Explanation

. The proximal edge of the lesser sigmoid notch of the ulna

Explanation

To avoid overstuffing the joint, the articular surface of the radial head prosthesis should sit flush with, or up to 1-2 mm proximal to, the proximal edge of the lesser sigmoid notch of the ulna when the elbow is reduced.

Question 323

Topic: Elbow & Forearm

A 45-year-old male sustains a terrible triad injury of the elbow. Operative management is planned. To optimize biomechanical stability, what is the most widely accepted sequence of structural repair?

. Lateral collateral ligament (LCL), radial head, coronoid, medial collateral ligament (MCL)
. Coronoid, radial head, LCL, MCL (if needed)
. Radial head, coronoid, MCL, LCL
. MCL, coronoid, radial head, LCL
. Radial head, LCL, coronoid, MCL

Correct Answer & Explanation

. Coronoid, radial head, LCL, MCL (if needed)

Explanation

The standard sequence of repair in a terrible triad injury proceeds from deep to superficial: coronoid fixation, radial head repair or replacement, and LCL repair. MCL repair or a hinged external fixator is only added if the elbow remains persistently unstable after the lateral side is reconstructed.

Question 324

Topic: Elbow & Forearm

A 50-year-old male undergoes open reduction and internal fixation for a Bado Type II Monteggia fracture. Following rigid plate fixation of the ulna, the radial head remains subluxated posteriorly. What is the most critical next step in management?

. Open reduction of the radial head and annular ligament reconstruction
. Resection of the radial head
. Application of a hinged external fixator
. Assessment and revision of the ulnar reduction and fixation
. Closed reduction and casting in full extension

Correct Answer & Explanation

. Assessment and revision of the ulnar reduction and fixation

Explanation

In Monteggia fractures, the key to reducing the radial head is anatomic restoration of the ulna's length and alignment. Persistent radial head subluxation after ulnar plating indicates ulnar malreduction, which must be addressed first.

Question 325

Topic: Elbow & Forearm

When evaluating pediatric forearm radiographs for a suspected Monteggia equivalent injury, which radiographic line is most reliable to confirm a reduced radiocapitellar joint?

. The anterior humeral line should bisect the middle third of the capitellum.
. The radiocapitellar line should bisect the capitellum in all radiographic views.
. Baumann's angle should measure less than 75 degrees.
. The coronoid line should intersect the radial neck.
. The radioulnar line must be parallel to the interosseous membrane.

Correct Answer & Explanation

. The radiocapitellar line should bisect the capitellum in all radiographic views.

Explanation

The radiocapitellar line is drawn through the center of the radial shaft and neck. To rule out a radial head dislocation, this line must intersect the center of the capitellum on every radiographic view, regardless of the elbow's flexion angle.

Question 326

Topic: Elbow & Forearm

During the lateral reconstruction phase of a terrible triad injury, the LCL complex must be reattached to its anatomic footprint to ensure isometric stability. Where is the precise isometric origin of the LCL on the humerus?

. Base of the lateral epicondyle, at the center of capitellar curvature
. Anterior and distal to the lateral epicondyle
. Posterior and proximal to the lateral epicondyle
. At the supracondylar ridge
. Directly on the articular margin of the capitellum

Correct Answer & Explanation

. Base of the lateral epicondyle, at the center of capitellar curvature

Explanation

The isometric point for the LCL (specifically the lateral ulnar collateral ligament, LUCL) is located at the center of rotation of the capitellum. This corresponds to the base of the lateral epicondyle.

Question 327

Topic: Elbow & Forearm

A 6-year-old child presents with an isolated plastic deformation of the ulna and an anterior radial head dislocation that occurred 3 weeks ago. Closed reduction attempts in the emergency department fail. What is the most appropriate management?

. Open reduction of the radial head with annular ligament reconstruction
. Osteotomy of the ulna to correct the bowing, followed by radial head reduction
. Excision of the radial head
. Observation until skeletal maturity
. Application of a hinged elbow brace

Correct Answer & Explanation

. Osteotomy of the ulna to correct the bowing, followed by radial head reduction

Explanation

Plastic deformation of the ulna acts as a Bado Type I Monteggia equivalent. Failure to correct the ulnar bowing prevents stable reduction of the radial head; therefore, an ulnar osteotomy is required.

Question 328

Topic: Elbow & Forearm

Which of the following characteristics is most closely associated with a Bado Type II Monteggia fracture-dislocation compared to other Bado types?

. It is the most common pattern in pediatric patients.
. It is frequently associated with radial head and coronoid fractures.
. It typically presents with a high radial nerve palsy.
. The radial head dislocates anteriorly.
. It is optimally treated with closed reduction and casting in adults.

Correct Answer & Explanation

. It is frequently associated with radial head and coronoid fractures.

Explanation

Bado Type II involves posterior dislocation of the radial head and a posterior angulated ulnar fracture. It is highly associated with elbow fracture-dislocations, including concomitant radial head and coronoid fractures.

Question 329

Topic: Elbow & Forearm
A Bado Type III Monteggia fracture-dislocation is radiographically defined by which of the following features?
. Anterior dislocation of the radial head with middle-third ulnar fracture
. Posterior dislocation of the radial head with proximal ulnar fracture
. Lateral or anterolateral dislocation of the radial head with proximal ulnar metaphyseal fracture
. Anterior dislocation of the radial head with a concomitant radial shaft fracture
. Isolated dislocation of the distal radioulnar joint (DRUJ)

Correct Answer & Explanation

. Lateral or anterolateral dislocation of the radial head with proximal ulnar metaphyseal fracture

Explanation

Bado Type III injuries feature a lateral or anterolateral dislocation of the radial head combined with a fracture of the proximal ulnar metaphysis. This pattern is primarily seen in pediatric patients.

Question 330

Topic: Elbow & Forearm

When performing open reduction and internal fixation of the radial head using a plate, the hardware must be placed within the "safe zone" to prevent impingement on the proximal radioulnar joint (PRUJ). This safe zone corresponds to an arc of approximately how many degrees?

. 45 degrees
. 90 degrees
. 180 degrees
. 270 degrees
. 360 degrees

Correct Answer & Explanation

. 90 degrees

Explanation

The "safe zone" for radial head hardware placement spans approximately 90 to 110 degrees on the non-articulating lateral aspect of the radial head. It is defined by an arc from the radial styloid to Lister's tubercle with the forearm in neutral rotation.

Question 331

Topic: Elbow & Forearm

Which of the following structures must be preserved or carefully repaired during the Boyd approach to the proximal ulna to prevent a debilitating complication in Monteggia fracture management?

. The superficial branch of the radial nerve
. The lateral ulnar collateral ligament (LUCL)
. The medial antebrachial cutaneous nerve
. The recurrent interosseous artery
. The anconeus insertion

Correct Answer & Explanation

. The lateral ulnar collateral ligament (LUCL)

Explanation

The Boyd approach reflects the supinator and anconeus off the proximal ulna. If dissection proceeds too far anteriorly or distally without protecting the lateral ligamentous complex, the LUCL can be compromised, resulting in iatrogenic posterolateral rotatory instability (PLRI).

Question 332

Topic: Elbow & Forearm

A 9-year-old patient presents with a displaced lateral condyle fracture. During open reduction and internal fixation (ORIF), the surgeon is meticulously clearing the fracture hematoma and preparing for reduction. Which of the following surgical maneuvers carries the highest risk of avascular necrosis (AVN) of the capitellum?

. Utilizing a direct lateral incision exploiting the internervous plane between the anconeus and extensor carpi ulnaris.
. Gently manipulating the metaphyseal fragment with a dental pick to achieve anatomic reduction.
. Aggressively stripping soft tissue attachments from the posterior aspect of the lateral condyle to improve visualization.
. Fixing the fracture with two divergent smooth Kirschner wires (K-wires) achieving bicortical purchase.
. Repairing the joint capsule and extensor aponeurosis meticulously with absorbable sutures after fixation.

Correct Answer & Explanation

. Aggressively stripping soft tissue attachments from the posterior aspect of the lateral condyle to improve visualization.

Explanation

Correct Answer: CThe teaching case explicitly highlights the critical vascular anatomy of the lateral condyle: 'The capitellum receives its primary blood supply from posterior end-arteries that enter the non-articular posterior aspect of the lateral condyle. There is no significant collateral circulation. Consequently, aggressive posterior soft tissue dissection during open reduction risks devascularizing the fragment, leading to avascular necrosis (AVN) of the capitellum.' Therefore, aggressively stripping soft tissue attachments from the posterior aspect of the lateral condyle is the maneuver with the highest risk of AVN.Option A is incorrect:The direct lateral incision utilizing the internervous plane between the anconeus and extensor carpi ulnaris (Kocher interval) is the standard and safe approach for lateral condyle fractures.Option B is incorrect:Gentle manipulation of the metaphyseal fragment with instruments like a dental pick or skin hook is a standard technique for achieving reduction and does not inherently risk AVN if performed carefully.Option D is incorrect:Fixation with two divergent smooth K-wires achieving bicortical purchase is the recommended and biomechanically stable method of internal fixation, not a cause of AVN.Option E is incorrect:Meticulous repair of the joint capsule and extensor aponeurosis is a crucial step to prevent late soft tissue prominence and does not contribute to AVN.

Question 333

Topic: Elbow & Forearm

A 5-year-old child sustains a lateral condyle fracture. The fracture fragment, which is largely cartilaginous at this age, includes the lateral metaphysis and the entire capitellum. Which of the following statements accurately describes the anatomical and biomechanical considerations relevant to this injury?

. The capitellum is the last ossification center to appear in the distal humerus, making it prone to physeal injury.
. The 'pull-off' theory suggests an axial load through the radius drives the radial head into the capitellum.
. Standard radiographs consistently overestimate the true size of the fractured segment due to the cartilaginous nature of the fragment.
. The fracture fragment invariably includes the lateral metaphysis, the entire capitellum, and a variable portion of the lateral trochlear ridge.
. The primary blood supply to the capitellum is from anterior collateral arteries, making posterior dissection safe.

Correct Answer & Explanation

. The fracture fragment invariably includes the lateral metaphysis, the entire capitellum, and a variable portion of the lateral trochlear ridge.

Explanation

Correct Answer: DThe teaching case states: 'At the typical age of injury (6 to 10 years), the lateral condyle is largely cartilaginous. The fracture fragment invariably includes the lateral metaphysis, the entire capitellum, and a variable portion of the lateral trochlear ridge.' This accurately describes the anatomical components of the fracture fragment.Option A is incorrect:The capitellum is thefirstossification center to appear (1-2 years), not the last. The external (lateral) epicondyle is the last (10-12 years).Option B is incorrect:The 'pull-off' theory suggests a varus force applied to an extended elbow causes avulsion by the lateral collateral ligament complex and common extensor origin. The 'push-off' theory describes the axial load through the radius.Option C is incorrect:Standard radiographs consistentlyunderestimatethe true size of the fractured segment because the majority of the fragment is radiolucent cartilage.Option E is incorrect:The primary blood supply to the capitellum is fromposteriorend-arteries, and aggressiveposteriorsoft tissue dissection risks devascularization, not anterior collateral arteries.

Question 334

Topic: Elbow & Forearm

A 7-year-old patient undergoes successful open reduction and internal fixation of a lateral condyle fracture. During the follow-up period, the patient develops a 'fishtail' deformity of the capitellum on radiographs. Which of the following complications is most consistent with this radiographic finding?

. Lateral spurring (overgrowth)
. Delayed union
. Cubitus valgus
. Avascular necrosis (AVN)
. Pin tract infection

Correct Answer & Explanation

. Avascular necrosis (AVN)

Explanation

Correct Answer: DThe teaching case specifically describes avascular necrosis (AVN) of the capitellum as 'often manifesting radiographically as a "fishtail" deformity.' This complication is typically caused by iatrogenic disruption of the posterior vascular supply during open reduction, leading to central capitellar collapse.Option A is incorrect:Lateral spurring (overgrowth) is common but usually asymptomatic and does not present as a 'fishtail' deformity.Option B is incorrect:Delayed union refers to slow healing of the fracture, not a specific deformity of the capitellum.Option C is incorrect:Cubitus valgus is an angular deformity of the elbow (increased carrying angle) often secondary to nonunion or premature physeal closure, but it is not described as a 'fishtail' deformity of the capitellum itself.Option E is incorrect:Pin tract infection is a localized infection around the K-wires and does not cause a 'fishtail' deformity of the capitellum.

Question 335

Topic: Elbow & Forearm

An 8-year-old girl falls onto an outstretched hand and presents with lateral elbow pain. Radiographs reveal a radial neck fracture with 45 degrees of angulation. The radial head is not displaced from the capitellum. What is the initial step in management?

. Open reduction and internal fixation
. Closed reduction with a percutaneous pin joystick (Metaizeau technique)
. Manual closed reduction under sedation
. Radial head excision
. Immobilization in a long arm cast without reduction

Correct Answer & Explanation

. Manual closed reduction under sedation

Explanation

For pediatric radial neck fractures with >30 degrees of angulation, manual closed reduction is the initial treatment of choice. Percutaneous or open techniques are reserved for cases where closed reduction fails to achieve acceptable alignment (<30 degrees).

Question 336

Topic: Elbow & Forearm

A 4-year-old child falls on an outstretched hand. A radiograph similar to

demonstrates a lateral condyle fracture. If this fracture is left untreated and goes on to nonunion, which of the following is the most classic long-term complication?

. Cubitus varus leading to radial nerve palsy
. Cubitus valgus leading to tardy ulnar nerve palsy
. Myositis ossificans of the brachialis
. Avascular necrosis of the capitellum
. Anterior interosseous nerve entrapment

Correct Answer & Explanation

. Cubitus valgus leading to tardy ulnar nerve palsy

Explanation

Nonunion of a pediatric lateral condyle fracture typically results in progressive cubitus valgus deformity. Over time, this valgus stretching can lead to a tardy ulnar nerve palsy.

Question 337

Topic: Elbow & Forearm

A 7-year-old falls onto an outstretched hand and sustains a Bado Type I Monteggia fracture-dislocation (anterior dislocation of the radial head with a proximal ulna fracture). What is the critical first step in the management of this injury?

. Open reduction of the radial head
. Closed reduction of the ulnar fracture
. Annular ligament reconstruction
. Radial head excision
. Immediate plate fixation of the ulna prior to any manipulation

Correct Answer & Explanation

. Closed reduction of the ulnar fracture

Explanation

In pediatric Monteggia fractures, closed reduction of the ulnar fracture typically results in spontaneous reduction of the radial head. If the radial head remains dislocated after anatomic ulnar reduction, soft tissue interposition should be suspected.

Question 338

Topic: Elbow & Forearm
Based on the expected chronological appearance of secondary ossification centers in the pediatric elbow (CRITOE), which center should be radiographically visible in a normal 6-year-old child, while the subsequent center is not yet visible?
. Capitellum
. Radial head
. Medial epicondyle
. Trochlea
. Olecranon

Correct Answer & Explanation

. Trochlea

Explanation

The CRITOE mnemonic dictates the appearance of ossification centers: Capitellum (1 year), Radius (3 years), Internal/Medial epicondyle (5 years), Trochlea (7 years), Olecranon (9 years), and External epicondyle (11 years). At 6 years old, the medial epicondyle is visible, but the trochlea is not.

Question 339

Topic: Elbow & Forearm

A 32-year-old competitive rower presents with pain and swelling on the dorsal radial aspect of his distal forearm. Examination reveals palpable crepitus approximately 4 to 6 cm proximal to Lister's tubercle during active wrist extension. This condition is caused by friction between which of the following extensor compartments?

. 1st and 2nd dorsal compartments
. 2nd and 3rd dorsal compartments
. 1st and 3rd dorsal compartments
. 3rd and 4th dorsal compartments
. 4th and 5th dorsal compartments

Correct Answer & Explanation

. 2nd and 3rd dorsal compartments

Explanation

Intersection syndrome occurs at the site where the muscle bellies of the 1st dorsal compartment (APL and EPB) cross over the tendons of the 2nd dorsal compartment (ECRL and ECRB), typically 4-6 cm proximal to Lister's tubercle.

Question 340

Topic: Elbow & Forearm
When interpreting pediatric elbow radiographs, understanding the chronologic appearance of secondary ossification centers is crucial. Which of the following sequences represents the normal order of ossification center appearance in a growing child?
. Capitellum, Radial head, Medial epicondyle, Trochlea, Olecranon, Lateral epicondyle
. Capitellum, Medial epicondyle, Radial head, Trochlea, Olecranon, Lateral epicondyle
. Radial head, Capitellum, Medial epicondyle, Olecranon, Trochlea, Lateral epicondyle
. Capitellum, Radial head, Trochlea, Medial epicondyle, Olecranon, Lateral epicondyle
. Medial epicondyle, Capitellum, Radial head, Trochlea, Olecranon, Lateral epicondyle

Correct Answer & Explanation

. Capitellum, Radial head, Medial epicondyle, Trochlea, Olecranon, Lateral epicondyle

Explanation

The mnemonic CRITOE (Capitellum, Radial head, Internal/Medial epicondyle, Trochlea, Olecranon, External/Lateral epicondyle) accurately describes the sequential appearance of the secondary ossification centers of the pediatric elbow.

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