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Elbow & Forearm MCQs

Practice Set 37 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 721

Topic: Elbow & Forearm

A 42-year-old male undergoes a two-incision technique for repair of a ruptured distal biceps tendon. Postoperatively, he is noted to have a new-onset nerve deficit characterized by the inability to actively extend his thumb and fingers at the metacarpophalangeal joints. When he attempts to extend his wrist, it deviates radially. Injury to which of the following nerves is the most likely cause?

. Superficial radial nerve
. Anterior interosseous nerve
. Posterior interosseous nerve
. Ulnar nerve
. Lateral antebrachial cutaneous nerve

Correct Answer & Explanation

. Posterior interosseous nerve

Explanation

The posterior interosseous nerve (PIN) is at high risk during the two-incision technique for distal biceps repair, particularly if the forearm is not fully pronated during the posterior dissection or through aggressive retraction. The PIN supplies the ECU, EDC, EDM, APL, EPB, EPL, and EIP. Injury results in the inability to actively extend the fingers and thumb. Because the extensor carpi radialis longus and brevis (ECRL, ECRB) are innervated by the radial nerve proper prior to its bifurcation, wrist extension is preserved but occurs with strong radial deviation due to the loss of the counterbalancing ECU.

Question 722

Topic: Elbow & Forearm

A 42-year-old tennis player presents with chronic, refractory lateral elbow pain that is exacerbated by wrist extension and gripping. He has failed 8 months of conservative management and is scheduled for surgical debridement. Histologic evaluation of the resected tissue is expected to show angiofibroblastic hyperplasia. The primary pathoanatomic lesion in this condition typically involves the origin of which structure?

. Extensor carpi radialis longus (ECRL)
. Extensor carpi radialis brevis (ECRB)
. Extensor digitorum communis (EDC)
. Extensor carpi ulnaris (ECU)
. Supinator muscle

Correct Answer & Explanation

. Extensor carpi radialis brevis (ECRB)

Explanation

Lateral epicondylitis (tennis elbow) is primarily a degenerative tendinosis characterized histologically by angiofibroblastic hyperplasia, rather than acute inflammation. The most commonly involved structure is the origin of the extensor carpi radialis brevis (ECRB). While the ECRL and EDC can occasionally be involved, the ECRB is the primary culprit due to its anatomical position overlying the radiocapitellar joint and its mechanical susceptibility to microtrauma during repetitive wrist extension.

Question 723

Topic: Elbow & Forearm

A 35-year-old man falls from a ladder and sustains a 'terrible triad' injury of the elbow. Which of the following lists the sequence of structures typically addressed during surgical management, from deep to superficial?

. Radial head, coronoid, medial collateral ligament.
. Coronoid, radial head, lateral collateral ligament complex.
. Lateral collateral ligament complex, radial head, coronoid.
. Coronoid, lateral collateral ligament complex, radial head.
. Radial head, lateral collateral ligament complex, coronoid.

Correct Answer & Explanation

. Coronoid, lateral collateral ligament complex, radial head.

Explanation

The 'terrible triad' of the elbow involves a coronoid fracture, a radial head fracture, and a lateral collateral ligament (LCL) tear, leading to posterolateral rotatory instability. The standard surgical protocol dictates repairing structures from deep/anterior to superficial/lateral. The typical sequence is: 1) fixation of the coronoid to restore the anterior buttress, 2) fixation or replacement of the radial head, and 3) repair of the LCL complex to the lateral epicondyle to restore lateral stability. The medial collateral ligament is typically only addressed if gross instability persists after these steps.

Question 724

Topic: Elbow & Forearm

A 32-year-old man falls from a ladder and sustains an elbow dislocation associated with a radial head fracture and a coronoid fracture. Following closed reduction of the elbow, he is taken to the operating room. What is the standard recommended sequence of surgical reconstruction for this injury?

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

Correct Answer & Explanation

. Radial head fixation/replacement, coronoid fixation, lateral collateral ligament repair

Explanation

The classic 'terrible triad' of the elbow consists of an elbow dislocation, radial head fracture, and coronoid fracture. The standard surgical sequence works from deep to superficial: first repairing or replacing the coronoid (to restore the anterior buttress), then fixing or replacing the radial head (to restore the anterior and valgus buttress), and finally repairing the lateral ulnar collateral ligament (LUCL) to restore posterolateral rotatory stability.

Question 725

Topic: Elbow & Forearm

A 42-year-old carpenter presents with chronic lateral elbow pain that worsens with gripping and resisted wrist extension. Nonoperative management over the past 12 months has failed, and he is scheduled for surgical debridement. The pathologic tissue in lateral epicondylitis most commonly involves the origin of which of the following muscles?

. Extensor carpi radialis longus
. Extensor carpi radialis brevis
. Extensor digitorum communis
. Brachioradialis
. Extensor carpi ulnaris

Correct Answer & Explanation

. Extensor carpi radialis brevis

Explanation

Lateral epicondylitis (tennis elbow) is a tendinosis characterized by angiofibroblastic hyperplasia. The most commonly and primarily affected structure is the origin of the extensor carpi radialis brevis (ECRB) tendon. While the extensor digitorum communis can sometimes be involved, the ECRB is considered the primary site of pathology.

Question 726

Topic: Elbow & Forearm

A 45-year-old man falls from a ladder and sustains an elbow dislocation. After closed reduction in the emergency department, radiographs are obtained as shown in the provided figure.

A subsequent CT scan confirms a type II coronoid fracture and a comminuted radial head fracture. During surgical intervention, what is the most appropriate sequence of repair to restore elbow stability?

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

Correct Answer & Explanation

. Coronoid, radial head, lateral collateral ligament, medial collateral ligament

Explanation

This patient has a terrible triad injury of the elbow (elbow dislocation, radial head fracture, and coronoid fracture). The standard surgical sequence for restoring stability involves deep to superficial and medial to lateral (if approached laterally). The accepted sequence is: 1) Coronoid fixation or anterior capsule repair, 2) Radial head replacement or fixation, 3) Lateral ulnar collateral ligament (LUCL) repair. If the elbow remains unstable after these steps, the medial collateral ligament (MCL) is repaired or a hinged external fixator is applied.

Question 727

Topic: Elbow & Forearm

A 45-year-old man falls onto his outstretched hand and sustains the injury shown in Figure 2. Which of the following is the most appropriate surgical sequence for managing this injury?

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

Correct Answer & Explanation

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

Explanation

The patient has sustained a terrible triad injury of the elbow (elbow dislocation, radial head fracture, and coronoid fracture). The standard surgical sequence generally progresses from deep to superficial: fixing the coronoid first (or placing the suture lasso), followed by the radial head (fixation or arthroplasty), then the lateral collateral ligament (LCL) repair. The medial collateral ligament (MCL) is only repaired if the elbow remains unstable in extension after the lateral side and bony structures have been addressed.

Question 728

Topic: Elbow & Forearm

In the standard surgical management of a terrible triad injury of the elbow (elbow dislocation, radial head fracture, coronoid fracture), which of the following represents the correct sequence of reconstruction to restore stability?

. Lateral ulnar collateral ligament (LUCL) repair, coronoid fixation, radial head arthroplasty, MCL repair if needed
. Coronoid fixation, radial head arthroplasty/fixation, LUCL repair, MCL repair if needed
. Radial head arthroplasty/fixation, LUCL repair, coronoid fixation, MCL repair if needed
. Medial collateral ligament (MCL) repair, coronoid fixation, radial head arthroplasty/fixation, LUCL repair
. Coronoid fixation, MCL repair, radial head arthroplasty/fixation, LUCL repair

Correct Answer & Explanation

. Coronoid fixation, radial head arthroplasty/fixation, LUCL repair, MCL repair if needed

Explanation

The standard "inside-out" sequence for repairing a terrible triad injury of the elbow is: 1) Coronoid fracture fixation or anterior capsular repair (addressing the deepest structure first), 2) Radial head fixation or replacement, and 3) Lateral ulnar collateral ligament (LUCL) repair. If the elbow remains unstable in extension after these steps, the medial collateral ligament (MCL) may be repaired or a hinged external fixator applied.

Question 729

Topic: Elbow & Forearm

A 7-year-old boy presents for evaluation of a left elbow deformity. He sustained a displaced supracondylar humerus fracture 2 years ago, which was treated with closed reduction and percutaneous pinning. Physical examination reveals a significant cubitus varus deformity. Which of the following statements regarding this condition is most accurate?

. It is typically a purely cosmetic deformity with no long-term functional implications.
. It is most commonly caused by post-traumatic growth arrest of the medial capitellum.
. It is usually the result of osseous malunion involving coronal plane rotation.
. It frequently leads to tardy median nerve palsy.
. Spontaneous remodeling is expected to correct the deformity by skeletal maturity.

Correct Answer & Explanation

. It is usually the result of osseous malunion involving coronal plane rotation.

Explanation

Cubitus varus ("gunstock deformity") is the most common long-term complication of supracondylar humerus fractures, occurring primarily due to malunion rather than physeal growth arrest. The malunion is typically a combination of extension, medial tilt, and internal rotation. Long-term studies have shown it can lead to functional issues, including an increased risk of lateral condyle fractures, posterolateral rotatory instability (PLRI), and tardy ulnar nerve palsy. Coronal plane deformities do not remodel with growth.

Question 730

Topic: Elbow & Forearm

A 40-year-old bodybuilder undergoes a single-incision anterior approach for the repair of a distal biceps tendon rupture. During his first postoperative visit, he complains of numbness and tingling along the radial aspect of his forearm. Which nerve was most likely injured during the procedure, and what is the most common mechanism?

. Posterior interosseous nerve; forceful deep retractor placement
. Superficial radial nerve; entrapment in the suture anchor
. Lateral antebrachial cutaneous nerve; traction during superficial dissection
. Medial antebrachial cutaneous nerve; aberrant skin incision
. Median nerve; deep drill plunge through the posterior cortex

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve; traction during superficial dissection

Explanation

The lateral antebrachial cutaneous nerve (LABCN), the terminal sensory branch of the musculocutaneous nerve, is the most commonly injured nerve during a single-incision anterior distal biceps repair. Injury is typically due to traction or stretch from retractors during the superficial approach, as the nerve runs closely alongside the cephalic vein in the lateral subcutaneous tissue. Posterior interosseous nerve (PIN) injury is more classically associated with the two-incision technique or deep retractor placement.

Question 731

Topic: Elbow & Forearm

A 40-year-old man sustains a 'terrible triad' injury of the elbow consisting of a posterior elbow dislocation, a radial head fracture, and a coronoid fracture. During open surgical reconstruction, what is the generally recommended sequence of fixation to reliably restore elbow stability?

. LCL repair, then coronoid fixation, then radial head fixation
. Radial head fixation, then coronoid fixation, then MCL repair
. Coronoid fixation, then radial head repair or replacement, then LCL repair
. MCL repair, then radial head fixation, then coronoid fixation
. LCL repair, then MCL repair, then radial head replacement

Correct Answer & Explanation

. Coronoid fixation, then radial head repair or replacement, then LCL repair

Explanation

The standard surgical algorithm for terrible triad injuries builds from deep to superficial and anterior to posterior. First, the coronoid fracture is fixed or its anterior capsule repaired (restoring the anterior buttress). Second, the radial head is fixed or replaced (restoring the anterior column). Finally, the lateral collateral ligament (LCL) complex is repaired to the lateral epicondyle to restore posterolateral rotatory stability.

Question 732

Topic: Elbow & Forearm

A 45-year-old woman sustains a terrible triad injury of the elbow after a fall from a height. She is taken to the operating room for surgical stabilization. After standard surgical approaches are made and the joint is debrided of loose bodies, what is the most widely accepted sequence of reconstruction to restore elbow stability?

. Lateral ulnar collateral ligament (LUCL) repair, radial head fixation/replacement, coronoid fixation
. Coronoid fixation, radial head fixation/replacement, LUCL repair
. Radial head fixation/replacement, coronoid fixation, medial collateral ligament (MCL) repair
. MCL repair, radial head fixation/replacement, LUCL repair
. LUCL repair, coronoid fixation, MCL repair

Correct Answer & Explanation

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

Explanation

The standard and most widely accepted surgical sequence for a terrible triad injury of the elbow proceeds from deep to superficial and anterior to posterior: first addressing the coronoid process, followed by the radial head, and finally the lateral ulnar collateral ligament (LUCL). If the elbow remains unstable after these structures are addressed, MCL repair or a hinged external fixator may be considered.

Question 733

Topic: Elbow & Forearm

A 36-year-old man undergoes surgical repair of an acute, complete distal biceps tendon rupture using a single-incision anterior approach. Postoperatively, he complains of numbness and tingling extending down the radial aspect of his volar forearm. Which of the following nerves was most likely injured or stretched during the procedure?

. Radial nerve
. Posterior interosseous nerve (PIN)
. Lateral antebrachial cutaneous nerve (LABCN)
. Medial antebrachial cutaneous nerve (MABCN)
. Anterior interosseous nerve (AIN)

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve (LABCN)

Explanation

The lateral antebrachial cutaneous nerve (LABCN) is the most commonly injured nerve during a single-incision anterior approach for distal biceps repair. It emerges between the biceps and brachialis proximally and lies in the subcutaneous tissue laterally in the forearm. Vigorous retraction on the lateral side of the wound places it at high risk. The PIN is more classically at risk during a two-incision approach or if retractors are poorly placed over the radial neck.

Question 734

Topic: Elbow & Forearm

During surgical reconstruction of a 'terrible triad' injury of the elbow, a surgeon sequentially performs a radial head arthroplasty and secures the coronoid fracture with a lasso suture technique. Intraoperative fluoroscopy reveals persistent posterolateral rotatory instability when the elbow is extended. What is the most appropriate next step in the surgical algorithm?

. Repair of the medial collateral ligament (MCL)
. Application of a hinged external fixator
. Repair of the lateral ulnar collateral ligament (LUCL)
. Cross-pinning of the radiocapitellar joint
. Fasciotomy of the forearm

Correct Answer & Explanation

. Repair of the lateral ulnar collateral ligament (LUCL)

Explanation

The terrible triad of the elbow consists of an elbow dislocation, radial head fracture, and coronoid fracture. The standard surgical algorithm dictates an outside-in or inside-out approach, prioritizing the restoration of deep osseous stabilizers before addressing the ligamentous structures. After the radial head and coronoid are stabilized (either by fixation or replacement), the lateral collateral ligament complex, specifically the lateral ulnar collateral ligament (LUCL), must be repaired to restore lateral stability and prevent posterolateral rotatory instability. Repair of the MCL or application of a hinged external fixator is reserved for cases where the elbow remains unstable despite osseous reconstruction and LUCL repair.

Question 735

Topic: Elbow & Forearm

A 6-year-old child presents with an acute Bado type I Monteggia fracture-dislocation (ulnar shaft fracture with anterior dislocation of the radial head). Following closed reduction of the ulnar shaft, the radial head remains anteriorly dislocated. What is the most appropriate next step in management?

. Open reduction of the radial head and annular ligament reconstruction
. Closed reduction of the radius and cast in extension
. Open reduction and internal fixation of the ulnar shaft fracture
. Excision of the radial head
. Application of an external fixator to the radius

Correct Answer & Explanation

. Open reduction and internal fixation of the ulnar shaft fracture

Explanation

In a pediatric Monteggia fracture-dislocation, the reduction of the radial head is entirely dependent on achieving anatomical length and alignment of the ulna. If closed reduction of the ulna fails to adequately reduce the radial head, or if the ulna alignment is lost, the next step is anatomic restoration of the ulna via ORIF or intramedullary nailing. Once the ulna is anatomically fixed, the radial head usually reduces spontaneously. Direct open reduction of the radial head is only indicated if it remains dislocated despite a perfectly anatomical ulnar reduction.

Question 736

Topic: Elbow & Forearm

A 45-year-old man undergoes surgical repair of a distal biceps tendon rupture via a single-incision anterior approach using a cortical button. Postoperatively, he reports numbness over the lateral aspect of his forearm. Which of the following nerves is most likely injured during this procedure?

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

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve

Explanation

The single-incision anterior approach for distal biceps tendon repair places the lateral antebrachial cutaneous nerve (LABCN) at greatest risk. The LABCN runs in the subcutaneous tissue lateral to the biceps tendon and can be injured during superficial dissection or by overzealous retraction. Injury to the posterior interosseous nerve (PIN) is classically associated with the two-incision technique if retractors are placed poorly around the radial neck, or if the tendon is passed through the interosseous membrane incorrectly.

Question 737

Topic: Elbow & Forearm

A 35-year-old woman falls on an outstretched hand and sustains a 'terrible triad' injury of the elbow, consisting of a posterior elbow dislocation, a comminuted radial head fracture, and a coronoid fracture. Which of the following ligamentous structures is the primary restraint to posterolateral rotatory instability (PLRI) and is invariably torn in this injury pattern?

. Anterior band of the medial collateral ligament (MCL)
. Lateral ulnar collateral ligament (LUCL)
. Radial collateral ligament
. Annular ligament
. Oblique cord

Correct Answer & Explanation

. Lateral ulnar collateral ligament (LUCL)

Explanation

The terrible triad of the elbow results from a valgus, axial, and posterolateral rotatory force that causes sequential failure of the lateral and medial soft tissue constraints, along with fractures of the radial head and coronoid. The lateral ulnar collateral ligament (LUCL) is the primary restraint to posterolateral rotatory instability (PLRI). It is invariably torn in a terrible triad injury and must be securely repaired to the lateral epicondyle to restore elbow stability.

Question 738

Topic: Elbow & Forearm

A 35-year-old male sustains a fall from a height, resulting in a complex elbow injury consisting of a radial head fracture, a type II coronoid fracture, and an elbow dislocation. During surgical reconstruction of this 'terrible triad' injury, what is the recommended sequence of fixation to optimally restore elbow stability?

. Radial head repair/replacement, lateral collateral ligament (LCL) repair, coronoid repair
. LCL repair, coronoid repair, radial head repair/replacement
. Coronoid repair, radial head repair/replacement, LCL repair
. Coronoid repair, LCL repair, radial head repair/replacement
. Medial collateral ligament repair, coronoid repair, LCL repair

Correct Answer & Explanation

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

Explanation

The classic 'terrible triad' of the elbow involves an elbow dislocation, radial head fracture, and coronoid fracture. The standard, most reliable surgical sequence to restore stability builds from deep to superficial and medial to lateral: 1) Repair of the coronoid process (often via sutures passed from posterior to anterior or through a specific approach), 2) Repair or replacement of the radial head, and 3) Repair of the lateral ulnar collateral ligament (LUCL) to its origin on the lateral epicondyle.

Question 739

Topic: Elbow & Forearm

A 45-year-old man falls from a ladder and sustains a 'terrible triad' injury to his left elbow. Surgical management is planned. Following standard treatment algorithms, what is the most appropriate sequence of reconstruction?

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

Correct Answer & Explanation

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

Explanation

The standard surgical algorithm for a terrible triad injury (elbow dislocation, coronoid fracture, radial head fracture) follows an inside-out or deep-to-superficial approach. The sequence is typically: 1) Coronoid fixation (or anterior capsule repair if the fragment is too small), 2) Radial head fixation or replacement, 3) Lateral collateral ligament (LCL) complex repair, and 4) Medial collateral ligament (MCL) repair and/or hinged external fixation if the elbow remains unstable after the first three steps.

Question 740

Topic: Elbow & Forearm

A 30-year-old man has a permanent radial nerve palsy following a severe crush injury to his arm 18 months ago. Tendon transfer surgery is planned to restore wrist, finger, and thumb extension. In a standard flexor carpi radialis (FCR) transfer, which of the following tendon transfers is most commonly used to restore wrist extension?

. Flexor carpi ulnaris (FCU) to extensor carpi radialis longus (ECRL)
. Pronator teres (PT) to extensor carpi radialis brevis (ECRB)
. Flexor digitorum superficialis (FDS) to extensor carpi radialis brevis (ECRB)
. Palmaris longus (PL) to extensor carpi radialis longus (ECRL)
. Flexor carpi radialis (FCR) to extensor carpi ulnaris (ECU)

Correct Answer & Explanation

. Pronator teres (PT) to extensor carpi radialis brevis (ECRB)

Explanation

In the standard tendon transfer for radial nerve palsy, wrist extension is typically restored by transferring the Pronator Teres (PT) to the Extensor Carpi Radialis Brevis (ECRB). The ECRB is preferred over the ECRL because its central insertion at the base of the third metacarpal provides pure, centralized wrist extension, reducing the risk of strong radial deviation. Finger extension is typically restored via FCR to Extensor Digitorum Communis (EDC), and thumb extension via Palmaris Longus (PL) to Extensor Pollicis Longus (EPL).

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