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Elbow & Forearm MCQs

Practice Set 23 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 441

Topic: Elbow & Forearm

A 13-year-old male baseball pitcher complains of lateral elbow pain. Radiographs reveal a radiolucent lesion with a sclerotic margin on the capitellum, and MRI demonstrates a detached osteochondral fragment. He has open physes. Which of the following most accurately differentiates osteochondritis dissecans (OCD) of the capitellum from Panner's disease?

. Panner's disease typically occurs in children under 10 and affects the entire capitellum without loose body formation
. OCD primarily affects the radial head, whereas Panner's disease affects the capitellum
. Panner's disease requires surgical drilling, whereas OCD is exclusively managed non-operatively
. OCD typically presents with ulnar neuropathy, whereas Panner's disease presents with median neuropathy
. Panner's disease involves the trochlea, whereas OCD involves the capitellum

Correct Answer & Explanation

. Panner's disease typically occurs in children under 10 and affects the entire capitellum without loose body formation

Explanation

Panner's disease is a self-limiting osteochondrosis of the capitellum that affects younger children (typically ages 7-10), involves the entire ossific nucleus, and rarely produces loose bodies. Capitellar OCD affects older adolescents (typically ages 12-15) involved in repetitive overhead sports, creates focal osteochondral defects, frequently results in loose bodies, and often requires surgery if unstable.

Question 442

Topic: Elbow & Forearm

A 35-year-old man sustained a mid-shaft humerus fracture resulting in a high radial nerve palsy that has shown no clinical or electromyographic signs of recovery at 12 months. In a standard set of tendon transfers (such as the Jones transfer) designed to restore hand and wrist function, which donor tendon is classically transferred to restore wrist extension?

. Flexor carpi ulnaris (FCU)
. Pronator teres (PT)
. Palmaris longus (PL)
. Flexor carpi radialis (FCR)
. Flexor digitorum superficialis (FDS)

Correct Answer & Explanation

. Pronator teres (PT)

Explanation

In a patient with a permanent high radial nerve palsy, tendon transfers are required to restore wrist extension, finger extension, and thumb extension. The classic transfer to restore wrist extension is the transfer of the Pronator Teres (PT) to the Extensor Carpi Radialis Brevis (ECRB). ECRB is chosen over ECRL to avoid radial deviation with extension. Finger extension is typically restored using either the FCU or FCR transferred to the Extensor Digitorum Communis (EDC). Thumb extension is restored by transferring the Palmaris Longus (PL) to the Extensor Pollicis Longus (EPL).

Question 443

Topic: Elbow & Forearm

In the standard flexor carpi radialis (FCR) tendon transfer utilized for a high radial nerve palsy, which muscle is typically transferred to the extensor pollicis longus (EPL) to restore thumb extension?

. Pronator teres
. Flexor carpi radialis
. Flexor carpi ulnaris
. Palmaris longus
. Flexor digitorum superficialis

Correct Answer & Explanation

. Flexor carpi radialis

Explanation

In the classic FCR tendon transfer for radial nerve palsy, the pronator teres is transferred to the ECRB, the FCR is transferred to the EDC, and the palmaris longus is transferred to the EPL.

Question 444

Topic: Elbow & Forearm

A patient with an isolated, irreparable high radial nerve palsy requires tendon transfers to restore wrist extension, finger extension, and thumb extension. Which of the following is the most standard and reliable donor muscle to restore wrist extension?

. Flexor carpi ulnaris (FCU)
. Flexor carpi radialis (FCR)
. Pronator teres (PT)
. Palmaris longus (PL)
. Flexor digitorum superficialis (FDS)

Correct Answer & Explanation

. Pronator teres (PT)

Explanation

The pronator teres (PT) is the most reliable and universally used donor muscle for transfer to the extensor carpi radialis brevis (ECRB) to restore wrist extension in radial nerve palsy. It has excellent excursion and synergistic function.

Question 445

Topic: Elbow & Forearm

In a patient with a chronic, irreversible radial nerve palsy, a standard tendon transfer procedure is planned to restore functional wrist and digit extension. To restore wrist extension, which of the following donor-recipient tendon transfers is most commonly utilized?

. Pronator teres to Extensor carpi radialis brevis (ECRB)
. Flexor carpi radialis to Extensor digitorum communis (EDC)
. Palmaris longus to Extensor pollicis longus (EPL)
. Flexor digitorum superficialis to Extensor digitorum communis (EDC)
. Flexor carpi ulnaris to Extensor carpi radialis brevis (ECRB)

Correct Answer & Explanation

. Pronator teres to Extensor carpi radialis brevis (ECRB)

Explanation

The standard set of tendon transfers for a high radial nerve palsy includes: 1) Pronator teres (PT) to Extensor carpi radialis brevis (ECRB) to restore wrist extension; 2) Flexor carpi radialis (FCR) or Flexor carpi ulnaris (FCU) to Extensor digitorum communis (EDC) to restore finger extension; and 3) Palmaris longus (PL) to Extensor pollicis longus (EPL) to restore thumb extension. The ECRB is chosen over the ECRL for wrist extension because its central insertion at the base of the third metacarpal minimizes radial deviation during active wrist extension.

Question 446

Topic: Elbow & Forearm

A surgeon plans to use a 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) vascularized bone graft for a scaphoid nonunion. During the dissection, the pedicle must be identified between the first and second dorsal extensor compartments. Which of the following pairs of tendons correctly defines the anatomic borders of these two compartments?

. Abductor pollicis longus and extensor pollicis longus
. Extensor pollicis brevis and extensor carpi radialis longus
. Extensor carpi radialis brevis and extensor pollicis longus
. Extensor digitorum communis and extensor digiti minimi
. Abductor pollicis longus and extensor pollicis brevis only

Correct Answer & Explanation

. Extensor pollicis brevis and extensor carpi radialis longus

Explanation

The 1,2 ICSRA runs longitudinally along the dorsal retinaculum between the 1st and 2nd extensor compartments. The 1st compartment contains the Abductor Pollicis Longus (APL) and Extensor Pollicis Brevis (EPB). The 2nd compartment contains the Extensor Carpi Radialis Longus (ECRL) and Extensor Carpi Radialis Brevis (ECRB). Therefore, the interval is directly between the EPB (ulnar border of the 1st compartment) and ECRL (radial border of the 2nd compartment).

Question 447

Topic: Elbow & Forearm

A patient with a high radial nerve palsy requires tendon transfers to restore wrist, finger, and thumb extension. To restore wrist extension, the Pronator Teres (PT) is most commonly transferred to the Extensor Carpi Radialis Brevis (ECRB) rather than the Extensor Carpi Radialis Longus (ECRL). What is the primary biomechanical rationale for selecting the ECRB?

. The ECRB has a longer excursion profile matching the PT
. Transfer to the ECRL produces excessive radial deviation during extension
. The ECRB tendon is located superficial to the superficial branch of the radial nerve
. The ECRB is a primary flexor of the MCP joints, augmenting grip strength
. The ECRB is less likely to undergo attritional rupture over the Lister tubercle

Correct Answer & Explanation

. Transfer to the ECRL produces excessive radial deviation during extension

Explanation

The Pronator Teres (PT) is the standard transfer to restore wrist extension in radial nerve palsy. It is transferred to the ECRB rather than the ECRL because the ECRB inserts more centrally at the base of the third metacarpal. Transferring to the ECRL (which inserts on the second metacarpal) would result in a functionally limiting supination and excessive radial deviation moment during wrist extension.

Question 448

Topic: Elbow & Forearm

In the surgical management of a 'terrible triad' injury of the elbow, what is the generally recommended sequence of repair to best restore concentric stability?

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

Correct Answer & Explanation

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

Explanation

The terrible triad consists of an elbow dislocation, radial head fracture, and coronoid fracture. The standard sequence of repair is deep to superficial: coronoid fixation first, followed by radial head repair or arthroplasty, and finally lateral collateral ligament (LCL) repair, and finally evaluating the need for MCL repair or hinged ex-fix.

Question 449

Topic: Elbow & Forearm

In the surgical management of a 'terrible triad' injury of the elbow (elbow dislocation, radial head fracture, coronoid fracture), which of the following represents the most widely accepted sequence of repair through a lateral approach?

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

Correct Answer & Explanation

. Coronoid, radial head, LCL, MCL if needed

Explanation

The standard surgical sequence for a terrible triad is 'deep to superficial' (or medial to lateral) from the lateral approach: repair/fix the coronoid first (often visualizing it through the defect left by the fractured radial head), then repair or replace the radial head, then repair the LCL complex. The MCL is typically only addressed if the elbow remains unstable in extension after the lateral-sided and intra-articular repairs are complete.

Question 450

Topic: Elbow & Forearm

A 45-year-old female falls on an outstretched hand and sustains a capitellum fracture. The fracture extends medially to include the lateral aspect of the trochlea, but the posterior condylar bone remains intact. According to the Dubberley classification, what type of fracture is this?

. Type 1A
. Type 2A
. Type 3A
. Type 1B
. Type 2B

Correct Answer & Explanation

. Type 2A

Explanation

Dubberley classification of capitellum fractures: Type 1: involves capitellum with or without lateral trochlear ridge. Type 2: involves capitellum and lateral trochlea as a single piece. Type 3: comminuted capitellum and lateral trochlea. 'A' indicates the posterior condyle is intact; 'B' indicates a posterior condylar fracture (loss of posterior support). The described fracture is Type 2A.

Question 451

Topic: Elbow & Forearm

A 45-year-old male sustains a terrible triad injury of the elbow. He undergoes operative management comprising radial head replacement, coronoid fracture fixation, and lateral ulnar collateral ligament (LUCL) repair. What is the most appropriate early postoperative rehabilitation protocol to maintain stability while promoting motion?

. Early active extension in forearm supination to protect the medial complex
. Active extension in forearm pronation, and flexion in any forearm position
. Immobilization in 90 degrees of flexion and full supination for 6 continuous weeks
. Passive range of motion only for the first 4 weeks to allow ligamentous healing
. Immediate varus and valgus stress testing at full extension to ensure ligament integrity

Correct Answer & Explanation

. Active extension in forearm pronation, and flexion in any forearm position

Explanation

Following a terrible triad repair (which intrinsically involves LUCL repair), early active motion is preferred to prevent stiffness. Active extension should be performed with the forearm in pronation. Pronation engages the radial head against the capitellum and protects the repaired lateral collateral ligament complex from excessive varus and posterolateral rotatory stress. Flexion is generally safe in any forearm position.

Question 452

Topic: Elbow & Forearm

A 38-year-old male undergoes a single-incision anterior distal biceps tendon repair using a cortical button technique. Postoperatively, he exhibits a complete inability to actively extend his thumb and fingers at the metacarpophalangeal (MP) joints, though his wrist extension is preserved with radial deviation. This complication is most likely due to injury to which structure, and during which surgical step?

. Lateral antebrachial cutaneous nerve during superficial dissection
. Posterior interosseous nerve (PIN) during drilling of the posterior cortex
. Median nerve during retrieval of the retracted tendon
. Radial nerve proper due to prolonged tourniquet ischemia
. Anterior interosseous nerve during deep retractor placement

Correct Answer & Explanation

. Posterior interosseous nerve (PIN) during drilling of the posterior cortex

Explanation

The posterior interosseous nerve (PIN) is at risk during the single-incision distal biceps repair, particularly when drilling the posterior (far) cortex of the radius or passing the cortical button. If the forearm is not fully pronated during this step, the PIN wraps closer to the drill trajectory. Injury results in PIN palsy: loss of finger and thumb MP extension (finger drop), but preserved wrist extension (with radial deviation) because the extensor carpi radialis longus is innervated by the radial nerve proper proximal to the PIN bifurcation.

Question 453

Topic: Elbow & Forearm

A 55-year-old male with an acute, highly comminuted intra-articular distal humerus fracture is being considered for elbow arthroplasty. Which of the following is an absolute contraindication for a distal humeral hemiarthroplasty?

. Age less than 60 years
. Presence of an intact coronoid and radial head
. Incompetence of the lateral ulnar collateral ligament (LUCL)
. Absence of a reconstructable radial head and coronoid
. Concomitant olecranon fracture

Correct Answer & Explanation

. Absence of a reconstructable radial head and coronoid

Explanation

Distal humeral hemiarthroplasty relies on the native proximal ulna and radius for stability and containment. The absence of an intact or reconstructable radial head and coronoid process is an absolute contraindication because it results in a highly unstable joint.

Question 454

Topic: Elbow & Forearm

During a radial head arthroplasty for a comminuted radial head fracture, the surgeon inadvertently inserts an implant that is 4 mm too thick. What is the most likely biomechanical consequence of this 'overstuffed' radiocapitellar joint?

. Medial collateral ligament (MCL) laxity and valgus instability
. Increased radiocapitellar joint pressures leading to capitellar cartilage wear and restricted flexion
. Proximal migration of the radius and positive ulnar variance
. Posterolateral rotatory instability (PLRI)
. Spontaneous rupture of the lateral ulnar collateral ligament (LUCL)

Correct Answer & Explanation

. Increased radiocapitellar joint pressures leading to capitellar cartilage wear and restricted flexion

Explanation

Overstuffing the radiocapitellar joint excessively loads the capitellum, causing rapid cartilage wear, lateral elbow pain, and a significant loss of elbow flexion and extension. It artificially tensions the lateral ligamentous complex, rather than causing laxity.

Question 455

Topic: Elbow & Forearm
The axis of forearm rotation occurs between what two anatomic points?
. Radial head, radial styloid
. Radial head, ulnar styloid
. Radial head, ulnar head
. Coronoid, sigmoid notch
. Coronoid, radial styloid

Correct Answer & Explanation

. Radial head, ulnar head

Explanation

Forearm rotation results from a complex interaction of osseous articulations and soft tissues including the radiocapitellar articulation, proximal and distal radioulnar joints, the interosseous membrane, and the adjacent forearm muscles. The rotation occurs around a longitudinal forearm axis extending from the center of the radial head proximally through the foveal region of the ulnar head distally.

Question 456

Topic: Elbow & Forearm

A 6-year-old boy presents for follow-up 6 weeks after closed reduction and casting of a Monteggia equivalent lesion. Radiographs reveal that the radial head is dislocated anteriorly, and the proximal ulna fracture has healed in apex-anterior angulation. What is the most appropriate management?

. Continued observation as the radial head will spontaneously reduce with remodeling
. Closed reduction of the radial head and application of a Muenster cast
. Open reduction of the radial head and annular ligament reconstruction alone
. Proximal ulna osteotomy with open reduction of the radial head
. Resection of the radial head

Correct Answer & Explanation

. Proximal ulna osteotomy with open reduction of the radial head

Explanation

A missed or chronic Monteggia fracture-dislocation in a child invariably stems from malreduction (angulation or length loss) of the ulna. The radial head cannot maintain reduction if the ulna length and alignment are not restored. Treatment requires a corrective osteotomy of the proximal ulna, combined with open reduction of the radial head. Radial head resection is contraindicated in children due to subsequent growth disturbances and wrist issues.

Question 457

Topic: Elbow & Forearm
A 42-year-old man falls from a ladder, sustaining a comminuted, un-reconstructible radial head fracture. Intraoperatively, after radial head excision, he is noted to have significant longitudinal translation of the radius. Examination of the wrist reveals dorsal prominence and gross instability of the distal ulna. What is the most appropriate definitive management of the elbow and wrist?
. Radial head replacement and pinning of the DRUJ in supination
. Radial head replacement and Darrach procedure of the distal ulna
. Radial head resection alone with early active motion
. Radial head replacement and Sauvé-Kapandji procedure
. Radial head resection and reconstruction of the interosseous membrane

Correct Answer & Explanation

. Radial head replacement and pinning of the DRUJ in supination

Explanation

This is a classic Essex-Lopresti injury, characterized by a radial head fracture, tear of the interosseous membrane, and disruption of the distal radioulnar joint (DRUJ). Because the central band of the IOM is incompetent, the radial head acts as the primary constraint to proximal migration of the radius. Radial head resection alone is strictly contraindicated as it leads to severe proximal migration of the radius and ulnocarpal impaction. Treatment mandates radial head replacement to restore longitudinal stability and stabilization of the DRUJ (usually by pinning the wrist in supination for 4-6 weeks).

Question 458

Topic: Elbow & Forearm

A 28-year-old patient sustained a midshaft humerus fracture with an associated radial nerve palsy that shows no clinical or electromyographic signs of recovery at 6 months. For restoration of functional wrist extension, what is the most common and reliable tendon transfer?

. Flexor carpi ulnaris (FCU) to Extensor digitorum communis (EDC)
. Flexor digitorum superficialis (FDS) to Extensor pollicis longus (EPL)
. Brachioradialis (BR) to Extensor carpi radialis brevis (ECRB)
. Pronator teres (PT) to Extensor carpi radialis brevis (ECRB)
. Palmaris longus (PL) to Extensor carpi ulnaris (ECU)

Correct Answer & Explanation

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

Explanation

The standard set of tendon transfers for a high radial nerve palsy includes transferring the Pronator Teres (PT) (innervated by the median nerve) to the Extensor Carpi Radialis Brevis (ECRB) to restore wrist extension. The ECRB is preferred over the ECRL because its central location prevents radial deviation during active wrist extension.

Question 459

Topic: Elbow & Forearm

A surgeon chooses to perform a distal biceps tendon repair using a two-incision technique rather than a single anterior incision. The two-incision technique historically carries a higher risk of which of the following complications compared to the single-incision technique?

. Lateral antebrachial cutaneous (LABC) nerve palsy
. Proximal radioulnar synostosis
. Median nerve palsy
. Brachial artery transection
. Posterior interosseous nerve (PIN) palsy

Correct Answer & Explanation

. Proximal radioulnar synostosis

Explanation

The two-incision technique for distal biceps repair exposes the patient to a higher risk of heterotopic ossification and proximal radioulnar synostosis because it dissects the interosseous membrane between the radius and ulna. In contrast, the single anterior incision approach carries a significantly higher risk of injury to the Lateral Antebrachial Cutaneous (LABC) nerve.

Question 460

Topic: Elbow & Forearm

A 40-year-old male sustained an elbow fracture-dislocation and is diagnosed with posteromedial rotatory instability (PMRI). Which of the following combinations of injury is the hallmark of PMRI?

. Radial head fracture, coronoid tip fracture, and lateral ulnar collateral ligament (LUCL) tear
. Anteromedial facet coronoid fracture and lateral ulnar collateral ligament (LUCL) tear
. Olecranon fracture and medial collateral ligament (MCL) tear
. Capitellum fracture and medial collateral ligament (MCL) tear
. Radial head fracture and complete disruption of the interosseous membrane

Correct Answer & Explanation

. Anteromedial facet coronoid fracture and lateral ulnar collateral ligament (LUCL) tear

Explanation

Posteromedial rotatory instability (PMRI) of the elbow occurs secondary to a varus and posteromedial rotatory force. The hallmark pathoanatomy includes an anteromedial facet fracture of the coronoid process combined with a tear of the lateral collateral ligament complex (specifically the LUCL). Failure to recognize and stabilize the anteromedial coronoid facet leads to rapid development of varus instability and early post-traumatic arthritis.

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