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Elbow & Forearm MCQs

Practice Set 34 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 661

Topic: Elbow & Forearm

A 14-year-old male presents with recurrent acute locking and catching of his elbow, particularly with extension. He denies any recent trauma. Radiographs are normal. What is the MOST likely diagnosis?

. Loose body in the elbow joint
. Osteochondritis dissecans of the capitellum
. Panner's disease
. Olecranon stress fracture
. Medial epicondylitis

Correct Answer & Explanation

. Loose body in the elbow joint

Explanation

Recurrent acute locking and catching of the elbow, especially with extension, in a young patient without acute trauma, is highly suggestive of a loose body (osteochondral fragment) within the joint. These loose bodies can become entrapped in the joint space, causing mechanical symptoms. While osteochondritis dissecans (OCD) of the capitellum is common in young athletes and can lead to loose bodies, the primary diagnosis for acute mechanical locking with normal radiographs would be a loose body, which could be from an undiagnosed prior OCD lesion or other traumatic event. Panner's disease is osteochondrosis of the capitellum in younger children (<10 years) and usually causes diffuse pain and limited motion, not acute locking. Olecranon stress fracture causes posterior pain. Medial epicondylitis causes medial epicondyle pain.

Question 662

Topic: Elbow & Forearm

A 42-year-old man falls from a ladder and sustains a 'terrible triad' injury to his right elbow. Surgical intervention is undertaken. After stable internal fixation of the coronoid process fracture and prosthetic replacement of the comminuted radial head, the elbow drops out of joint when placed in extension and supination. What is the most appropriate next step in the surgical sequence?

. Application of a hinged external fixator
. Repair of the lateral ulnar collateral ligament (LUCL)
. Repair of the medial ulnar collateral ligament (MUCL)
. Release of the common extensor origin
. Fasciotomy of the forearm

Correct Answer & Explanation

. Application of a hinged external fixator

Explanation

The 'terrible triad' of the elbow consists of an elbow dislocation, a radial head fracture, and a coronoid fracture. The standard surgical algorithm progresses from deep to superficial: 1) Fixation of the coronoid to restore the anterior buttress, 2) Repair or replacement of the radial head to restore the lateral column, and 3) Repair of the lateral ulnar collateral ligament (LUCL) to address posterolateral rotatory instability. If the elbow remains unstable in extension after LUCL repair, the next step is typically repair of the medial collateral ligament (MUCL) or application of a hinged external fixator. Since the LUCL has not yet been addressed in this scenario, it is the appropriate next step.

Question 663

Topic: Elbow & Forearm

A 40-year-old male undergoes a distal biceps tendon repair via a single-incision anterior approach using a cortical button. Postoperatively, he is unable to extend his metacarpophalangeal joints and thumb interphalangeal joint, but he has strong wrist extension with radial deviation. Which nerve was most likely injured during the procedure?

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

Correct Answer & Explanation

. Posterior interosseous nerve (PIN)

Explanation

The posterior interosseous nerve (PIN) is at risk during a single-incision anterior approach for distal biceps repair, especially if the drill or cortical button plunges too deeply through the posterior cortex of the radius. Injury to the PIN results in paralysis of the finger and thumb extensors as well as the extensor carpi ulnaris (ECU). Wrist extension is preserved but deviates radially because the extensor carpi radialis longus (ECRL) is innervated by the radial nerve proper, proximal to the PIN bifurcation.

Question 664

Topic: Elbow & Forearm

A 38-year-old male undergoes a single-incision anterior approach for the repair of a retracted distal biceps tendon rupture using a suspensory cortical button technique. In the recovery room, the patient demonstrates a weak, radially-deviated wrist extension and a complete inability to actively extend his fingers and thumb at the metacarpophalangeal joints. Sensation over the dorsum of the hand is entirely intact. Which of the following is the most likely mechanism for this postoperative complication?

. Iatrogenic laceration of the superficial radial nerve during superficial dissection
. Traction neuropraxia of the posterior interosseous nerve due to forceful lateral retraction
. Thermal necrosis of the median nerve during electrocautery of the recurrent radial artery branches
. Compression of the lateral antebrachial cutaneous nerve by the surgical dressing
. Tethering of the anterior interosseous nerve within the pronator teres

Correct Answer & Explanation

. Iatrogenic laceration of the superficial radial nerve during superficial dissection

Explanation

The patient is exhibiting signs of a Posterior Interosseous Nerve (PIN) palsy. The PIN is purely motor (supplying the extensor digitorum, extensor pollicis longus/brevis, extensor carpi ulnaris, etc.), which explains the loss of digit extension and intact sensation. Wrist extension is preserved but radially deviated because the extensor carpi radialis longus (ECRL) and often the extensor carpi radialis brevis (ECRB) are innervated by the radial nerve proper before it bifurcates. In a single-incision anterior approach to the distal biceps, the PIN is at significant risk within the supinator muscle. The most common mechanism of injury is traction neuropraxia caused by vigorous radial/lateral retraction of the brachioradialis and supinator to visualize the radial tuberosity.

Question 665

Topic: Elbow & Forearm

A 42-year-old man falls on an outstretched hand and sustains a 'terrible triad' injury of the elbow. Surgical fixation is planned. To optimize stability and follow standard surgical principles, what is the most appropriate sequence of repair for the injured structures?

. Coronoid fixation, radial head repair or replacement, and lateral ulnar collateral ligament (LUCL) repair
. Radial head replacement, LUCL repair, and coronoid fixation
. LUCL repair, coronoid fixation, and radial head repair
. Coronoid fixation, medial collateral ligament (MCL) repair, and LUCL repair
. Radial head repair, MCL repair, and coronoid fixation

Correct Answer & Explanation

. Coronoid fixation, radial head repair or replacement, and lateral ulnar collateral ligament (LUCL) repair

Explanation

The terrible triad of the elbow consists of an elbow dislocation, a radial head fracture, and a coronoid process fracture. The standard surgical algorithm follows a 'deep to superficial' and 'medial to lateral' approach. The typical sequence is: 1) Coronoid fracture fixation or anterior capsule repair, 2) Radial head repair or replacement, 3) Lateral ulnar collateral ligament (LUCL) repair, and 4) Medial collateral ligament (MCL) repair (only if the elbow remains unstable after the first three steps).

Question 666

Topic: Elbow & Forearm

A 38-year-old male weightlifter undergoes repair of a complete distal biceps tendon rupture via a classic two-incision approach. During his postoperative course, what complication is significantly more frequent with this surgical approach compared to a single-incision anterior approach?

. Lateral antebrachial cutaneous nerve neuropraxia
. Proximal radioulnar synostosis
. Posterior interosseous nerve palsy
. Median nerve injury
. Brachial artery injury

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve neuropraxia

Explanation

The two-incision approach for distal biceps repair was historically developed to avoid the radial nerve (PIN) injuries associated with a single anterior incision. However, it carries a significantly higher risk of heterotopic ossification and proximal radioulnar synostosis due to the dissection through the interosseous membrane and around the ulna. The single-incision anterior approach carries a higher risk of lateral antebrachial cutaneous nerve (LABCN) neuropraxia and posterior interosseous nerve (PIN) injury.

Question 667

Topic: Elbow & Forearm

A 42-year-old male falls from a height and sustains a 'terrible triad' injury of the elbow, which includes an elbow dislocation, a comminuted radial head fracture, and a Type II coronoid fracture. Operative intervention is planned. To optimize stability, what is the most widely accepted surgical sequence for addressing these lesions?

. Lateral collateral ligament repair, radial head replacement, coronoid fixation
. Coronoid fixation, radial head replacement, lateral collateral ligament repair
. Radial head replacement, lateral collateral ligament repair, coronoid fixation
. Medial collateral ligament repair, coronoid fixation, radial head replacement
. Lateral collateral ligament repair, medial collateral ligament repair, radial head replacement

Correct Answer & Explanation

. Lateral collateral ligament repair, radial head replacement, coronoid fixation

Explanation

The 'terrible triad' of the elbow includes an elbow dislocation, radial head fracture, and coronoid fracture. The standard surgical algorithm follows a deep-to-superficial repair sequence to restore stability. First, the anterior capsule and coronoid are fixed to restore the anterior buttress. Second, the radial head is repaired or replaced. Finally, the lateral ulnar collateral ligament (LUCL/LCL complex) is repaired. MCL repair is rarely necessary unless the elbow remains unstable after the standard sequence.

Question 668

Topic: Elbow & Forearm

A 45-year-old competitive weightlifter undergoes surgical repair of a distal biceps tendon rupture using a single-incision anterior approach. On his first postoperative visit, he complains of numbness and tingling along the lateral aspect of his forearm. Motor function of the hand and wrist is completely intact. Which of the following anatomical structures was most likely injured or stretched during the surgical exposure?

. Median nerve
. Superficial radial nerve
. Lateral antebrachial cutaneous nerve
. Posterior interosseous nerve
. Medial antebrachial cutaneous nerve

Correct Answer & Explanation

. Median nerve

Explanation

The lateral antebrachial cutaneous nerve (LABC) is the terminal sensory branch of the musculocutaneous nerve. It exits the deep fascia just lateral to the biceps tendon and is highly vulnerable to traction neuropraxia or transection during a single-incision anterior approach for distal biceps repair. Injury results in numbness along the lateral aspect of the forearm. The posterior interosseous nerve (PIN) is more commonly at risk during a two-incision approach (particularly if the forearm is not kept in supination during the posterolateral exposure) or if retractors are placed too deep radially.

Question 669

Topic: Elbow & Forearm

A 42-year-old male weightlifter feels a sudden pop in his anterior elbow during a heavy deadlift. Clinical examination reveals a positive hook test. He undergoes surgical repair via a single-incision anterior approach. Postoperatively, he complains of numbness and paresthesias over the lateral aspect of his forearm. Which of the following nerves was most likely injured or retracted excessively during the surgical exposure?

. Lateral antebrachial cutaneous nerve
. Radial nerve
. Posterior interosseous nerve
. Median nerve
. Musculocutaneous nerve motor branch

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve

Explanation

The lateral antebrachial cutaneous nerve (LABCN) is the sensory continuation of the musculocutaneous nerve. It exits the deep fascia lateral to the biceps tendon and is the most commonly injured nerve during a single-incision anterior approach for distal biceps tendon repair. Injury results in numbness or paresthesias over the lateral forearm.

Question 670

Topic: Elbow & Forearm

A 35-year-old man falls from a ladder and sustains an elbow dislocation associated with a radial head fracture and a coronoid fracture. He is taken to the operating room for surgical reconstruction. To optimally restore elbow stability in this 'terrible triad' injury, what is the generally recommended sequence of repair?

. Coronoid fracture, Lateral collateral ligament, Radial head
. Lateral collateral ligament, Radial head, Coronoid fracture
. Coronoid fracture, Radial head, Lateral collateral ligament
. Radial head, Lateral collateral ligament, Coronoid fracture
. Radial head, Coronoid fracture, Lateral collateral ligament

Correct Answer & Explanation

. Coronoid fracture, Lateral collateral ligament, Radial head

Explanation

The standard surgical algorithm for a 'terrible triad' injury of the elbow involves repairing the deep structures first, progressing from medial to lateral and deep to superficial. The typical sequence is: 1) Coronoid fracture fixation or anterior capsule repair, 2) Radial head fixation or replacement, and 3) Lateral collateral ligament (LCL) complex repair.

Question 671

Topic: Elbow & Forearm

A 24-year-old female sustains a severe fall onto an outstretched hand. Imaging reveals a coronal shear fracture of the capitellum that extends medially into the lateral trochlear ridge (Type IV capitellar fracture). She is scheduled for open reduction and internal fixation. Which surgical approach provides the most optimal visualization for addressing this specific fracture pattern?

. Posterior universally (triceps-splitting) approach
. Medial over-the-top approach
. Extensile lateral approach
. Anterior Henry approach
. Standard medial approach

Correct Answer & Explanation

. Posterior universally (triceps-splitting) approach

Explanation

Coronal shear fractures of the distal humerus involving the capitellum and extending into the trochlea (McKee modification Type IV) are best addressed via an extensile lateral approach. This allows excellent exposure of the anterior capitellum and lateral trochlea for placement of headless compression screws from anterior to posterior.

Question 672

Topic: Elbow & Forearm

A 42-year-old recreational weightlifter undergoes a classic two-incision approach (Boyd-Anderson) for a distal biceps tendon rupture repair. Six months postoperatively, he complains of severe stiffness in forearm rotation. Examination reveals a hard block with only 10 degrees of pronation and 15 degrees of supination. Which of the following technical errors during the index procedure is most likely responsible for this complication?

. Injury to the lateral antebrachial cutaneous nerve
. Entrapment of the posterior interosseous nerve (PIN)
. Overtensioning of the biceps tendon during cortical button fixation
. Subperiosteal stripping and exposure of the proximal ulna
. Failure to repair the lacertus fibrosus

Correct Answer & Explanation

. Injury to the lateral antebrachial cutaneous nerve

Explanation

The patient has developed a proximal radioulnar synostosis (heterotopic ossification bridging the radius and ulna), which is a devastating complication of the two-incision distal biceps repair. This typically occurs due to subperiosteal stripping or inappropriate exposure of the ulna during the posterior approach, leading to bleeding and cross-union. Modern modifications (such as Morrey's muscle-splitting approach) specifically avoid exposing the ulna to prevent this complication.

Question 673

Topic: Elbow & Forearm

A 6-year-old boy presents to the emergency department after falling off playground equipment. Radiographs demonstrate an isolated plastic deformation of the ulnar shaft and an anteriorly dislocated radial head. Which of the following is the most critical step in the initial management to ensure a stable reduction of the radial head?

. Closed reduction and casting of the elbow in full extension
. Immediate open reduction of the radial head followed by ulnar plating
. Closed reduction of the ulna with complete restoration of its anatomic bow
. Surgical reconstruction of the annular ligament
. Immobilization in 120 degrees of flexion without manipulating the ulna

Correct Answer & Explanation

. Closed reduction and casting of the elbow in full extension

Explanation

This is a Bado Type I Monteggia equivalent fracture (plastic deformation of the ulna with anterior radial head dislocation). In pediatric patients, the absolute key to reducing and maintaining the radial head is restoring the exact anatomic length and alignment (the normal bow) of the ulna. If the ulnar plastic deformity is not corrected, the radial head will remain unstable or completely irreducible. Annular ligament reconstruction is rarely needed in acute pediatric cases.

Question 674

Topic: Elbow & Forearm

A 45-year-old woman falls on an outstretched hand and sustains a 'terrible triad' injury of the elbow. She undergoes operative management. During the procedure, the surgeon decides to repair the lateral ulnar collateral ligament (LUCL) to the lateral epicondyle using a suture anchor. Where is the precise isometric origin of the LUCL on the lateral epicondyle?

. At the center of the capitellum axis of rotation
. Just anterior to the center of the capitellum axis
. Just posterior to the center of the capitellum axis
. Distal to the center of the capitellum axis
. Proximal to the center of the capitellum axis

Correct Answer & Explanation

. At the center of the capitellum axis of rotation

Explanation

The isometric point for LUCL reconstruction or repair on the lateral epicondyle is located at the center of the axis of rotation of the capitellum. Placing the anchor or graft at this exact point ensures uniform tension on the ligament throughout the elbow's full range of motion, which is crucial for restoring posterolateral rotatory stability in a terrible triad injury.

Question 675

Topic: Elbow & Forearm

A 32-year-old woman sustains a coronal shear fracture of the distal humerus extending medially to include the lateral aspect of the trochlea (McKee modification of Bryan and Morrey Type IV). She is scheduled for open reduction and internal fixation. Which of the following structures is most commonly injured with this fracture pattern and must be carefully evaluated for repair during surgery?

. Ulnar nerve
. Medial collateral ligament
. Lateral ulnar collateral ligament (LUCL)
. Annular ligament
. Distal biceps tendon

Correct Answer & Explanation

. Ulnar nerve

Explanation

Coronal shear fractures of the distal humerus that extend medially to include the lateral trochlea (McKee modification of a Type IV capitellum fracture) are frequently associated with injuries to the lateral collateral ligament complex, particularly the LUCL. The extensor origin and LUCL may be avulsed from the lateral epicondyle by the trauma itself or may need to be elevated to adequately access and fix the fracture. Repairing the LUCL at the conclusion of the case is critical to prevent posterolateral rotatory instability.

Question 676

Topic: Elbow & Forearm

A 42-year-old male heavy laborer feels a 'pop' in his anterior elbow while lifting a 50-lb box. Clinical examination demonstrates a reverse Popeye deformity and weakness in forearm supination. He undergoes an anatomic single-incision repair of the distal biceps tendon using a cortical button. Which of the following nerve complications is most classically associated with the anterior single-incision approach to the distal biceps?

. Anterior interosseous nerve neuropraxia
. Lateral antebrachial cutaneous nerve neuropraxia
. Posterior interosseous nerve (PIN) palsy
. Ulnar nerve entrapment
. Median nerve transection

Correct Answer & Explanation

. Anterior interosseous nerve neuropraxia

Explanation

The single-incision anterior approach for distal biceps repair is most commonly associated with lateral antebrachial cutaneous nerve (LABCN) neuropraxia due to the nerve's superficial location crossing the surgical field near the cephalic vein. While posterior interosseous nerve (PIN) injury can occur with aggressive radial retraction, LABCN injury is the most frequent neurologic complication. Heterotopic ossification and radioulnar synostosis are historically more common with the two-incision (Boyd-Anderson) approach.

Question 677

Topic: Elbow & Forearm

A 45-year-old man falls on an outstretched hand and sustains a 'terrible triad' injury of the elbow. Imaging confirms a posterior elbow dislocation, a comminuted radial head fracture, and a Regan-Morrey Type 2 coronoid fracture. During surgical reconstruction, after addressing the radial head and repairing the anterior capsule/coronoid, the elbow remains unstable to varus stress and tends to subluxate posterolaterally. Which of the following structures must be repaired next to restore stability?

. Lateral ulnar collateral ligament (LUCL)
. Anterior bundle of the medial collateral ligament (AMCL)
. Brachialis tendon
. Annular ligament
. Common flexor origin

Correct Answer & Explanation

. Lateral ulnar collateral ligament (LUCL)

Explanation

The standard surgical sequence for a terrible triad injury of the elbow involves: 1) fixing or replacing the radial head, 2) repairing the coronoid fracture or anterior capsule, 3) repairing the lateral collateral ligament (specifically the LUCL) to the lateral epicondyle, and 4) evaluating and repairing the medial collateral ligament only if the elbow remains unstable in extension after the lateral side is fixed. Posterolateral rotatory instability is prevented by restoring the LUCL.

Question 678

Topic: Elbow & Forearm

A 42-year-old man falls on his outstretched hand and sustains a "terrible triad" injury of the elbow. Which of the following represents the most widely accepted sequence of surgical reconstruction for this specific injury pattern?

. LCL repair, MCL repair, radial head fixation/replacement, coronoid fixation
. Coronoid fixation, radial head fixation/replacement, LCL repair, MCL repair (if needed)
. Radial head fixation/replacement, coronoid fixation, MCL repair, LCL repair
. Coronoid fixation, LCL repair, radial head fixation/replacement, MCL repair
. LCL repair, radial head fixation/replacement, coronoid fixation, MCL repair

Correct Answer & Explanation

. LCL repair, MCL repair, radial head fixation/replacement, coronoid fixation

Explanation

The standard surgical sequence for a terrible triad injury (defined as an elbow dislocation with fractures of the radial head and coronoid process) proceeds from deep to superficial. The classic algorithmic approach described by Ring and Jupiter is to first fix or reconstruct the coronoid fracture, followed by radial head fixation or arthroplasty, and finally repair of the lateral collateral ligament (LCL) complex. The medial collateral ligament (MCL) is rarely repaired unless there is gross persistent valgus instability after the lateral and anterior structures are stabilized.

Question 679

Topic: Elbow & Forearm

A 35-year-old male sustains a "terrible triad" injury to his left elbow following a fall from a height. The standard surgical sequence for reconstruction typically involves which of the following steps?

. Medial collateral ligament repair, followed by radial head fixation/replacement, then coronoid fixation, and finally lateral collateral ligament repair.
. Radial head fixation/replacement, followed by coronoid fixation, then lateral collateral ligament repair, and medial collateral ligament repair only if unstable.
. Coronoid fixation, followed by radial head fixation/replacement, then lateral ulnar collateral ligament (LUCL) repair, and finally medial collateral ligament repair if still unstable.
. Lateral ulnar collateral ligament repair, followed by radial head replacement, then coronoid fixation.
. Coronoid fixation, followed by medial collateral ligament repair, then radial head fixation, and finally LUCL repair.

Correct Answer & Explanation

. Medial collateral ligament repair, followed by radial head fixation/replacement, then coronoid fixation, and finally lateral collateral ligament repair.

Explanation

The "terrible triad" of the elbow includes an elbow dislocation, a radial head fracture, and a coronoid process fracture. The classic surgical treatment algorithm, as described by Pugh and McKee, proceeds from deep to superficial and typically from medial to lateral (when approaching from the lateral side). The standard sequence is: 1) Fixation of the coronoid fracture (to restore the anterior buttress), 2) Fixation or replacement of the radial head (to restore the anterior and valgus buttress), 3) Repair of the lateral collateral ligament complex (specifically the LUCL, to restore posterolateral rotatory stability). Repair of the medial collateral ligament (MCL) or application of a hinged external fixator is reserved for cases where the elbow remains unstable after the first three steps are completed.

Question 680

Topic: Elbow & Forearm

A 45-year-old male presents after a fall on an outstretched hand, sustaining a 'terrible triad' injury of the elbow. Which of the following best describes the appropriate surgical sequence and principles to restore joint stability?

. Fix coronoid, replace radial head, repair medial collateral ligament (MCL), then lateral ulnar collateral ligament (LUCL) if still unstable
. Fix coronoid, fix/replace radial head, repair LUCL, then repair MCL or apply hinged external fixator if still unstable
. Repair LUCL, fix coronoid, replace radial head, then repair MCL
. Replace radial head, repair LUCL, repair MCL, then fix coronoid
. Fix coronoid, repair MCL, fix radial head, repair LUCL

Correct Answer & Explanation

. Fix coronoid, replace radial head, repair medial collateral ligament (MCL), then lateral ulnar collateral ligament (LUCL) if still unstable

Explanation

The standard surgical protocol for a terrible triad injury (coronoid fracture, radial head fracture, and elbow dislocation resulting in a LUCL tear) follows an inside-out or deep-to-superficial approach. The sequence typically involves: 1) fixing the coronoid process, 2) fixing or replacing the radial head, and 3) repairing the LUCL to the lateral epicondyle. If the elbow remains unstable after these steps, the MCL is repaired or a hinged external fixator is placed.

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