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Elbow & Forearm MCQs

Practice Set 3 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 41

Topic: Elbow & Forearm
The parents of a 12-year-old boy notice an abnormal shape on their son's forearm. He states that he does not feel any pain. Based on his radiograph (Slide), the most likely diagnosis is:
. Congenital dislocation of the radial head
. Unrecognized traumatic dislocation of the radial head
. Osteogenesis imperfecta
. Fibrous dysplasia
. Multiple exostoses

Correct Answer & Explanation

. Multiple exostoses

Explanation

This patient has multiple exostoses. Multiple exostoses, which result from a mutation on one of three EXT genes, cause a growth disturbance of affected limb segments. This effect is most pronounced in the two-bone segments (forearm and lower leg). The bone with the exostoses grows less in length and often develops angulation. The less-affected bone often develops secondary deformity, such as the radial head dislocation in this patient. Fibrous dysplasia and osteogenesis imperfecta may lead to developmental dislocation of the radial head as well, but the associated bony changes allow correct diagnosis of each of these conditions.

Question 42

Topic: Elbow & Forearm
In a lateral radiograph of a child's elbow, the anterior humeral line should be located:
. Anterior to the capitellum
. In the anterior one-third of the capitellum
. In the middle-third of the capitellum
. In the posterior-third of the capitellum
. Posterior to the capitellum

Correct Answer & Explanation

. In the middle-third of the capitellum

Explanation

In a child's elbow, the anterior humeral line should be located in the middle-third of the capitellum.

Question 43

Topic: Elbow & Forearm

Based on the elbow radiograph of a 5-year-old child presenting with acute trauma (

), what is the most significant long-term complication if a widely displaced lateral condyle fracture goes entirely unrecognized and develops into a nonunion?

. Cubitus varus
. Tardy ulnar nerve palsy
. Radial nerve palsy
. Avascular necrosis of the radial head
. Heterotopic ossification

Correct Answer & Explanation

. Tardy ulnar nerve palsy

Explanation

A nonunion of the lateral condyle typically leads to progressive cubitus valgus deformity. Over time, the valgus stretch causes a tardy ulnar nerve palsy.

Question 44

Topic: Elbow & Forearm

A 14-year-old boy with a known diagnosis of Multiple Hereditary Exostoses (MHE) presents with a progressive forearm deformity. Which of the following describes the most classic forearm deformity seen in these patients?

. Radial lengthening and ulnar bowing
. Ulnar shortening and radial bowing
. Bilateral radioulnar synostosis
. Madelung-type dorsal radial bowing
. Proximal radial head hypertrophy

Correct Answer & Explanation

. Ulnar shortening and radial bowing

Explanation

The classic MHE forearm deformity involves relative ulnar shortening (due to distal ulnar osteochondromas tethering growth) and consequent radial bowing. This often leads to radial head subluxation or dislocation.

Question 45

Topic: Elbow & Forearm

A 4-year-old sustains a trauma to the forearm. Radiographs demonstrate an accentuated bowing of the ulna without an obvious cortical breach, and an anterior dislocation of the radial head. The initial step in the reduction maneuver for the ulnar plastic deformation should involve:

. Application of continuous traction only
. Immobilization in a Muenster cast without manipulation
. Application of a corrective bending force opposite to the deformity
. Immediate open osteotomy
. Percutaneous intramedullary nailing

Correct Answer & Explanation

. Application of a corrective bending force opposite to the deformity

Explanation

Plastic deformation of the ulna must be actively reduced by applying a constant corrective bending force (often over an apex like the surgeon's knee) for several minutes. Failing to correct the ulnar bow will prevent stable reduction of the radial head.

Question 46

Topic: Elbow & Forearm

A 3-year-old girl is brought to the clinic because she keeps her right elbow partially flexed and pronated. Her father reports he pulled her up by the hand onto a sidewalk step. What is the pathophysiology of her suspected condition?

. Subluxation of the radial head with interposition of the annular ligament
. Avulsion of the biceps tendon from the radial tuberosity
. Subluxation of the ulnohumeral joint with collateral ligament sprain
. Osteochondral defect of the capitellum
. Traction injury to the lower trunk of the brachial plexus

Correct Answer & Explanation

. Subluxation of the radial head with interposition of the annular ligament

Explanation

The clinical picture describes "nursemaid's elbow" (radial head subluxation). It occurs from an axial traction force on an extended and pronated forearm, causing the annular ligament to slip over the radial head and become interposed in the joint.

Question 47

Topic: Elbow & Forearm

An 8-year-old aspiring baseball pitcher complains of lateral elbow pain. Radiographs reveal flattening and sclerosis of the capitellum. The physis is open. What is the most likely diagnosis?

. Medial epicondyle apophysitis
. Panner disease
. Osteochondritis dissecans (OCD) of the radial head
. Lateral epicondylitis
. Little league elbow

Correct Answer & Explanation

. Panner disease

Explanation

Panner disease is a self-limiting osteochondrosis of the capitellum occurring typically in children under 10 years old. In contrast, osteochondritis dissecans (OCD) of the capitellum usually affects older adolescents and carries a worse prognosis.

Question 48

Topic: Elbow & Forearm
A 9-year-old boy sustains a radial neck fracture with 45 degrees of angulation. Closed reduction in the emergency department fails. What is the most appropriate next step in management?
. Open reduction and plate fixation
. Open reduction and cross-pinning
. Closed reduction with percutaneous intramedullary pinning (Métaizeau technique)
. Radial head excision
. Cast immobilization in current position

Correct Answer & Explanation

. Closed reduction with percutaneous intramedullary pinning (Métaizeau technique)

Explanation

For pediatric radial neck fractures with unacceptable angulation (>30 degrees) that fail closed reduction, percutaneous intramedullary pinning (Métaizeau technique) is the treatment of choice. Open reduction is avoided if possible due to the high risk of avascular necrosis.

Question 49

Topic: Elbow & Forearm

A radiograph of a 7-year-old child's forearm

reveals an isolated fracture of the proximal ulna with apex anterior angulation. Which of the following is the most critical next step in evaluating this radiograph?

. Assess for an associated distal radius fracture
. Assess the radiocapitellar alignment to rule out a radial head dislocation
. Check the Baumann angle of the elbow
. Evaluate for a coronoid fracture
. Measure the ulnar variance

Correct Answer & Explanation

. Assess the radiocapitellar alignment to rule out a radial head dislocation

Explanation

An isolated ulnar shaft fracture should immediately raise suspicion for a Monteggia fracture-dislocation. The radiocapitellar line must be evaluated on all views to ensure the radial head is normally aligned with the capitellum.

Question 50

Topic: Elbow & Forearm

Which of the following aspects of reconstruction of chronic posttraumatic dislocation of the radial head has not been shown to improve the success rate:

. Apex-posterior angulation
. Rigid fixation
. Slight lengthening
. Early range of motion
. Radiocapitellar pin fixation

Correct Answer & Explanation

. Apex-posterior angulation

Explanation

Reconstruction with an ulnar osteotomy with apex-posterior angulation and slight lengthening with rigid fixation to allow early range of motion have been shown to improve results. Radiocapitellar pin fixation may cause arthrosis, breakage, and infection so it is not routinely recommended.

Question 51

Topic: Elbow & Forearm

In the surgical management of a 'terrible triad' injury of the elbow, which of the following sequences of repair is generally recommended to best restore stability?

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

Correct Answer & Explanation

. Coronoid, radial head, LCL

Explanation

Standard protocol for terrible triad reconstruction proceeds from deep to superficial and typically from anterior to posterior. The sequence is fixing the coronoid, then repairing or replacing the radial head, and finally repairing the lateral collateral ligament (LCL).

Question 52

Topic: Elbow & Forearm

A 35-year-old female sustains a Dubberley Type 3B capitellum fracture. What specific anatomical feature distinguishes a Type B from a Type A in the Dubberley classification?

. Involvement of the lateral epicondyle
. Extension into the trochlea
. Presence of posterior condylar comminution
. Associated radial head fracture
. Associated lateral collateral ligament tear

Correct Answer & Explanation

. Presence of posterior condylar comminution

Explanation

The Dubberley classification divides capitellum fractures based on the presence (Type B) or absence (Type A) of posterior condylar comminution. This is critical because Type B fractures lack posterior cortical support and often require specific fixation strategies.

Question 53

Topic: Elbow & Forearm

When surgically reconstructing a terrible triad injury of the elbow, which of the following represents the most accepted and standard sequence of repair?

. LCL repair, followed by coronoid fixation, then radial head arthroplasty
. Coronoid fixation, followed by radial head repair/arthroplasty, then LCL repair
. Radial head arthroplasty, followed by coronoid fixation, then LCL repair
. Radial head arthroplasty, followed by LCL repair, then coronoid fixation
. Coronoid fixation, followed by LCL repair, then radial head repair

Correct Answer & Explanation

. Coronoid fixation, followed by radial head repair/arthroplasty, then LCL repair

Explanation

The standard inside-out sequence for repairing a terrible triad injury is coronoid fixation first, followed by radial head replacement or fixation, and finally LCL repair. This restores the deep skeletal stabilizers before reconstructing the lateral ligamentous constraints.

Question 54

Topic: Elbow & Forearm

A patient presents with a Dubberley Type 3B fracture of the capitellum. In this classification system, what does the suffix "B" specifically denote?

. Trochlear involvement
. Posterior articular comminution
. Medial column extension
. Associated radial head fracture
. Anterior cortical comminution

Correct Answer & Explanation

. Posterior articular comminution

Explanation

In the Dubberley classification of capitellum fractures, Type 3 denotes comminution. The addition of the suffix "B" indicates posterior articular comminution, which implies a lack of a bony buttress and often necessitates bone grafting or excision.

Question 55

Topic: Elbow & Forearm

The lateral ulnar collateral ligament (LUCL) is the primary stabilizing structure preventing posterolateral rotatory instability (PLRI) of the elbow. Where does this ligament distally insert?

. Radial neck
. Annular ligament
. Supinator crest of the ulna
. Coronoid process
. Olecranon tip

Correct Answer & Explanation

. Supinator crest of the ulna

Explanation

The lateral ulnar collateral ligament (LUCL) acts as a sling supporting the radial head and prevents PLRI. It originates on the lateral epicondyle and inserts on the supinator crest of the proximal ulna.

Question 56

Topic: Elbow & Forearm

In the surgical management of a "terrible triad" injury of the elbow, which of the following sequences of reconstruction provides the most biomechanically stable construct?

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

Correct Answer & Explanation

. Coronoid, LCL, radial head

Explanation

Standard protocol for terrible triad reconstruction generally proceeds from deep to superficial. This involves fixing or replacing the coronoid first, followed by the radial head, and finally repairing the lateral collateral ligament (LCL) complex.

Question 57

Topic: Elbow & Forearm

A 35-year-old patient presents with recurrent clicking and giving way of the elbow when pushing up from a chair. The lateral ulnar collateral ligament (LUCL) is suspected to be deficient. Which physical exam test is most specific for this condition?

. Milking maneuver
. Moving valgus stress test
. Pivot shift test of the elbow
. Hook test
. Tinel's sign at the cubital tunnel

Correct Answer & Explanation

. Pivot shift test of the elbow

Explanation

The lateral pivot shift test of the elbow specifically evaluates for posterolateral rotatory instability (PLRI) caused by LUCL insufficiency. It involves applying an axial load, valgus stress, and supination while flexing the elbow.

Question 58

Topic: Elbow & Forearm

A 6-year-old boy sustains a Bado Type I Monteggia fracture-dislocation. Closed reduction of the ulna is achieved, but the radial head remains anteriorly dislocated. What is the most common anatomical block to reduction of the radial head in this scenario?

. Interposed annular ligament
. Biceps tendon entrapment
. Median nerve entrapment
. Osteochondral fragment from the capitellum
. Brachialis muscle belly

Correct Answer & Explanation

. Interposed annular ligament

Explanation

The annular ligament is the most common structure that becomes interposed and blocks closed reduction of the radial head in a pediatric Monteggia fracture-dislocation. Open reduction is frequently required to extricate the ligament.

Question 59

Topic: Elbow & Forearm

A 45-year-old female falls on an outstretched hand and sustains a Hahn-Steinthal (Type I) capitellum fracture. Which of the following accurately describes this fracture pattern?

. A large osseous fragment of the capitellum involving a significant portion of the trochlea
. An articular cartilage shear fracture with very little subchondral bone
. A comminuted fracture of the capitellum
. A coronal shear fracture extending into the lateral epicondyle
. An avulsion fracture of the lateral collateral ligament origin

Correct Answer & Explanation

. A large osseous fragment of the capitellum involving a significant portion of the trochlea

Explanation

A Hahn-Steinthal (Type I) fracture involves a large osseous piece of the capitellum and often includes a portion of the lateral trochlea. In contrast, a Kocher-Lorenz (Type II) fracture is an articular cartilage shear with minimal subchondral bone.

Question 60

Topic: Elbow & Forearm

A 30-year-old man falls from a height, sustaining a comminuted radial head fracture and distal radioulnar joint (DRUJ) dislocation. Which of the following management steps is strictly contraindicated?

. Open reduction and internal fixation of the radial head
. Radial head arthroplasty
. Radial head excision alone
. Pinning of the DRUJ in supination
. Repair of the triangular fibrocartilage complex

Correct Answer & Explanation

. Radial head arthroplasty

Explanation

In an Essex-Lopresti injury, the interosseous membrane is disrupted. Excision of the radial head without replacement removes the proximal stabilizing column, leading to severe proximal radial migration and chronic wrist dysfunction.

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