Menu

Elbow & Forearm MCQs

Practice Set 55 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 1081

Topic: Elbow & Forearm

A 35-year-old female undergoes surgical fixation for a 'terrible triad' injury of the elbow. Following standard principles of elbow reconstruction, what is the recommended sequential order of structural repair?

. Coronoid fixation, followed by radial head repair/replacement, followed by lateral collateral ligament (LCL) repair
. Radial head repair/replacement, followed by coronoid fixation, followed by lateral collateral ligament (LCL) repair
. Lateral collateral ligament (LCL) repair, followed by radial head repair/replacement, followed by coronoid fixation
. Coronoid fixation, followed by medial collateral ligament (MCL) repair, followed by radial head repair/replacement
. Radial head repair/replacement, followed by lateral collateral ligament (LCL) repair, followed by coronoid fixation

Correct Answer & Explanation

. Coronoid fixation, followed by radial head repair/replacement, followed by lateral collateral ligament (LCL) repair

Explanation

The standard surgical algorithm for a terrible triad injury follows a 'deep to superficial' and 'medial to lateral' progression through a lateral approach. The sequence is: 1) Coronoid fracture fixation (often through the defect left by the fractured radial head), 2) Radial head repair or replacement, and 3) LCL complex repair to the lateral epicondyle.

Question 1082

Topic: Elbow & Forearm

When performing open reduction and internal fixation of a radial head fracture, the hardware must be placed within the 'safe zone' to prevent impingement on the proximal radioulnar joint (PRUJ) during forearm rotation. Which of the following accurately describes this safe zone?

. An arc of 90 degrees centered over the anteromedial quadrant of the radial head
. An arc of 90 to 110 degrees on the lateral aspect of the radial head, directly opposite the radial tuberosity
. An arc of 180 degrees encompassing the entire lateral half of the radial head
. The area between the coronoid process and the tip of the olecranon
. Directly over the bicipital tuberosity

Correct Answer & Explanation

. An arc of 90 to 110 degrees on the lateral aspect of the radial head, directly opposite the radial tuberosity

Explanation

The safe zone of the radial head represents the non-articulating portion that does not impinge on the lesser sigmoid notch of the ulna during pronation and supination. It corresponds to an arc of approximately 90 to 110 degrees located laterally, directly opposite the radial tuberosity.

Question 1083

Topic: Elbow & Forearm

A 35-year-old female falls on an outstretched hand and sustains a coronal shear fracture of the distal humerus. CT scan demonstrates a fracture extending medially to involve the entire capitellum and the majority of the trochlea, with a separate fragment of the posterior trochlea. Based on the Bryan and Morrey classification (modified by McKee), what type of fracture is this?

. Type 1 (Hahn-Steinthal)
. Type 2 (Kocher-Lorenz)
. Type 3 (Broberg-Morrey)
. Type 4
. Type 5

Correct Answer & Explanation

. Type 4

Explanation

McKee modified the Bryan and Morrey classification of capitellum fractures by adding the Type 4 fracture. This is a coronal shear fracture involving the capitellum that extends medially to include most or all of the trochlea, creating a complete articular shear.

Question 1084

Topic: Elbow & Forearm

A 45-year-old male undergoes a distal biceps tendon repair utilizing a single-incision anterior approach with cortical button fixation. Two weeks postoperatively, he complains of numbness over the lateral aspect of his forearm. Which nerve was most likely injured during the procedure?

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

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve (LABCN)

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 approach for distal biceps repair. It runs between the biceps and brachialis and courses superficially in the lateral forearm.

Question 1085

Topic: Elbow & Forearm

A 35-year-old male sustains a 'terrible triad' injury of the elbow (dislocation, radial head fracture, and type II coronoid fracture). Surgical intervention is planned. To optimize stability and follow standard principles of reconstruction, what is the most widely accepted sequence for repairing these structures?

. Coronoid fixation, MCL repair, radial head repair, LCL repair
. Radial head repair, LCL repair, coronoid fixation, MCL repair
. Coronoid fixation, radial head repair or replacement, LCL repair, followed by MCL repair only if still unstable
. LCL repair, radial head repair, coronoid fixation, MCL repair
. MCL repair, radial head repair, LCL repair, coronoid fixation

Correct Answer & Explanation

. Coronoid fixation, radial head repair or replacement, LCL repair, followed by MCL repair only if still unstable

Explanation

The standard protocol for treating terrible triad injuries is a 'deep to superficial' or 'inside-out' approach. The sequence is: 1) Fixation of the coronoid process (to restore the anterior buttress), 2) Repair or replacement of the radial head, 3) Repair of the lateral collateral ligament (LCL) complex. The medial collateral ligament (MCL) is typically only repaired if the elbow remains unstable in extension after the first three steps are completed.

Question 1086

Topic: Elbow & Forearm

A patient is scheduled for open reduction and internal fixation of a capitellar fracture classified as Dubberley type 3B. In the Dubberley classification system, what specific anatomic finding distinguishes a 'type B' lesion from a 'type A' lesion?

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

Correct Answer & Explanation

. Presence of posterior condylar comminution

Explanation

The Dubberley classification for capitellum and trochlea fractures is highly relevant for surgical planning. Type 1 is a capitellum-only fracture; Type 2 involves the capitellum and trochlea in a single piece; Type 3 involves the capitellum and trochlea as separate fragments. The modifier 'A' indicates no posterior comminution, whereas 'B' indicates posterior comminution. Type B fractures are more complex, often requiring posterior structural grafting or total elbow arthroplasty in older patients.

Question 1087

Topic: Elbow & Forearm

A 48-year-old man undergoes a two-incision (Boyd-Anderson) repair of a distal biceps tendon rupture. To minimize the specific complication of postoperative proximal radioulnar synostosis, which of the following surgical techniques is most critical?

. Using a cortical button rather than suture anchors for fixation
. Avoiding subperiosteal elevation and limiting exposure of the ulnar periosteum
. Maintaining the forearm strictly in pronation during the entire procedure
. Performing a complete excision of the bicipitoradial bursa
. Using a single-incision anterior approach instead

Correct Answer & Explanation

. Avoiding subperiosteal elevation and limiting exposure of the ulnar periosteum

Explanation

Proximal radioulnar synostosis is a devastating complication historically associated with the two-incision approach for distal biceps repair. The risk is significantly reduced by limiting subperiosteal dissection of the ulna during the posterolateral exposure and by thoroughly irrigating bone debris to prevent an osteogenic bridge between the radius and ulna.

Question 1088

Topic: Elbow & Forearm

A 45-year-old man undergoes anatomic repair of a distal biceps tendon rupture via a single-incision anterior approach. Postoperatively, he reports altered sensation along the radial aspect of his proximal forearm. Which nerve is most likely injured?

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

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve (LABCN)

Explanation

The lateral antebrachial cutaneous nerve (LABCN) is a terminal branch of the musculocutaneous nerve and provides sensation to the radial aspect of the forearm. It is the most commonly injured nerve during a single-incision anterior approach to the distal biceps due to its proximity to the surgical field and superficial position. The posterior interosseous nerve (PIN) is more at risk with deep dissection or retractors placed around the radial neck, or classically during the posterolateral exposure of a two-incision technique.

Question 1089

Topic: Elbow & Forearm

A 40-year-old construction worker falls from a ladder, sustaining a highly comminuted radial head fracture. The treating surgeon elects to perform a radial head resection alone. Six months later, the patient presents with severe ulnar-sided wrist pain and grip weakness. Radiographs demonstrate proximal migration of the radius. This complication is the hallmark of an unrecognized injury to which of the following structures?

. Distal radioulnar joint (DRUJ) ligaments and interosseous membrane
. Triangular fibrocartilage complex (TFCC) alone
. Lateral ulnar collateral ligament (LUCL)
. Annular ligament
. Proximal radioulnar joint capsule

Correct Answer & Explanation

. Distal radioulnar joint (DRUJ) ligaments and interosseous membrane

Explanation

The clinical scenario describes an Essex-Lopresti injury, which involves a radial head fracture with concomitant disruption of the interosseous membrane (IOM) and the distal radioulnar joint (DRUJ), leading to longitudinal radioulnar dissociation. Excision of the radial head in this setting removes the secondary stabilizer to proximal radial migration, resulting in severe ulnocarpal impaction. Treatment mandates radial head replacement (not excision) and DRUJ pinning.

Question 1090

Topic: Elbow & Forearm

A 28-year-old male sustains a 'terrible triad' injury of the elbow (radial head fracture, coronoid fracture, and elbow dislocation). Operative management is planned. According to standardized treatment protocols, which of the following represents the optimal surgical sequence for addressing this injury?

. Radial head fixation/replacement, LCL repair, Coronoid fixation
. LCL repair, Coronoid fixation, Radial head fixation/replacement
. Coronoid fixation, Radial head fixation/replacement, LCL repair
. Radial head fixation/replacement, Coronoid fixation, MCL repair
. Coronoid fixation, MCL repair, Radial head fixation/replacement

Correct Answer & Explanation

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

Explanation

The standard surgical sequence for a terrible triad injury of the elbow (Pugh et al.) begins deep and works superficial, usually from a lateral or dual approach: 1) Fixation of the coronoid fracture to restore the anterior buttress, 2) Fixation or replacement of the radial head to restore the anterior column/valgus buttress, and 3) Repair of the lateral collateral ligament (LCL/LUCL) complex. The MCL is typically only repaired if the elbow remains grossly unstable after these steps.

Question 1091

Topic: Elbow & Forearm

To diagnose posterolateral rotatory instability (PLRI) of the elbow, a pivot-shift test can be performed. The test aims to subluxate the radial head posteriorly relative to the capitellum. Which of the following combinations of forces must the examiner apply to the patient's arm during elbow flexion to successfully elicit this subluxation?

. Axial load, varus stress, and forearm pronation
. Axial load, varus stress, and forearm supination
. Axial load, valgus stress, and forearm pronation
. Axial load, valgus stress, and forearm supination
. Traction, valgus stress, and forearm pronation

Correct Answer & Explanation

. Axial load, valgus stress, and forearm supination

Explanation

Posterolateral rotatory instability (PLRI) is caused by insufficiency of the lateral ulnar collateral ligament (LUCL). To elicit the pivot-shift sign, the examiner starts with the elbow in extension and applies an axial load, valgus stress, and forearm supination. As the elbow is flexed, the radial head subluxates posterolaterally, typically clunking back into place around 40 degrees of flexion as triceps tension increases.

Question 1092

Topic: Elbow & Forearm

A 9-year-old Little League baseball pitcher presents with a 3-month history of lateral elbow pain, stiffness, and occasional swelling. Radiographs reveal sclerosis, fragmentation, and rarefaction of the entire capitellar ossific nucleus. The capitellar physis remains wide open. What is the most appropriate management for this condition?

. Arthroscopic debridement and microfracture of the capitellum
. Cessation of throwing activities and symptomatic observation
. Ulnar collateral ligament reconstruction
. Open reduction and internal fixation of the capitellum
. Radial head excision

Correct Answer & Explanation

. Cessation of throwing activities and symptomatic observation

Explanation

This clinical and radiographic picture is characteristic of Panner's disease, an osteochondrosis of the capitellum that affects younger children (typically boys aged 7-10 years) with an open capitellar physis. It involves the entire capitellum and has an excellent prognosis, almost always resolving with nonoperative management (rest and cessation of throwing). This distinguishes it from osteochondritis dissecans (OCD) of the capitellum, which occurs in older adolescents (12-15 years), involves focal defects, and may result in loose bodies requiring surgery.

Question 1093

Topic: Elbow & Forearm

A patient with a chronic high radial nerve palsy is scheduled for a standard Boyes tendon transfer procedure to restore hand function. In a classic Boyes transfer, which of the following muscles is transferred to restore thumb extension?

. Palmaris longus
. Flexor carpi radialis (FCR)
. Flexor digitorum superficialis (FDS) of the middle finger
. Flexor carpi ulnaris (FCU)
. Brachioradialis

Correct Answer & Explanation

. Flexor digitorum superficialis (FDS) of the middle finger

Explanation

In the Boyes tendon transfer for radial nerve palsy, the FDS of the middle finger is transferred to the Extensor Digitorum Communis (EDC) to restore finger extension, and the FDS of the ring finger is transferred to the Extensor Pollicis Longus (EPL) and Extensor Indicis Proprius (EIP) to restore thumb and index extension. The Pronator Teres (PT) is transferred to the Extensor Carpi Radialis Brevis (ECRB) for wrist extension. Note that in a standard FCR or FCU transfer (not Boyes), the Palmaris longus is typically transferred to the EPL.

Question 1094

Topic: Elbow & Forearm

In a patient undergoing tendon transfers for an irreparable high radial nerve palsy, the Pronator Teres (PT) is typically transferred to the Extensor Carpi Radialis Brevis (ECRB) rather than the Extensor Carpi Radialis Longus (ECRL). What is the primary biomechanical advantage of selecting the ECRB?

. It provides significantly greater excursion than the ECRL.
. It prevents radial deviation of the wrist during active extension.
. It preserves the functional integrity of the dart-thrower's motion.
. It requires a shorter routing path, reducing the risk of tendon adhesions.
. It acts as a synergistic muscle, eliminating the need for postoperative motor re-education.

Correct Answer & Explanation

. It prevents radial deviation of the wrist during active extension.

Explanation

The ECRB inserts centrally at the base of the third metacarpal, whereas the ECRL inserts more radially at the base of the second metacarpal. Transferring the PT to the ECRB provides balanced, centralized wrist extension, thereby preventing the unwanted radial deviation that would occur if the ECRL were used.

Question 1095

Topic: Elbow & Forearm

A patient with an isolated low radial nerve palsy undergoes tendon transfer surgery. To restore thumb extension, which of the following is the most classic and widely utilized donor tendon transfer?

. Palmaris longus (PL) to Extensor pollicis longus (EPL)
. Brachioradialis (BR) to Extensor pollicis longus (EPL)
. Flexor digitorum superficialis (FDS) to Extensor pollicis longus (EPL)
. Flexor carpi radialis (FCR) to Extensor pollicis longus (EPL)
. Pronator teres (PT) to Extensor pollicis longus (EPL)

Correct Answer & Explanation

. Palmaris longus (PL) to Extensor pollicis longus (EPL)

Explanation

In a standard set of tendon transfers for low radial nerve palsy, the Palmaris Longus (PL) is rerouted to the Extensor Pollicis Longus (EPL) to restore thumb extension. The standard Boyes or FCR transfer sets both utilize PL to EPL. Other components typically include PT to ECRB (for wrist extension) and FCR or FDS to EDC (for finger extension).

Question 1096

Topic: Elbow & Forearm

In a standard Boyes tendon transfer for a high radial nerve palsy, which muscle is transferred to restore wrist extension?

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

Correct Answer & Explanation

. Pronator teres

Explanation

In virtually all classic radial nerve palsy tendon transfers (including Boyes, Jones, and Smith), the pronator teres (PT) is transferred to the extensor carpi radialis brevis (ECRB) to predictably restore wrist extension.

Question 1097

Topic: Elbow & Forearm

A 26-year-old elite rower presents with pain, swelling, and distinct crepitus approximately 4 cm proximal to Lister's tubercle on the dorsal forearm. The pain is exacerbated by repetitive wrist flexion and extension. This condition represents an inflammatory friction syndrome between which of the following extensor compartments?

. First and second compartments
. Second and third compartments
. Third and fourth compartments
. First and third compartments
. Fourth and fifth compartments

Correct Answer & Explanation

. First and second compartments

Explanation

Intersection syndrome is characterized by tenosynovitis at the crossing point of the first dorsal compartment muscles (APL and EPB) over the second dorsal compartment muscles (ECRL and ECRB) in the distal forearm.

Question 1098

Topic: Elbow & Forearm

A 35-year-old male presents with a high radial nerve palsy following a humerus fracture. He is planned for a Boyes tendon transfer to restore wrist and finger extension. Which of the following describes the standard Boyes transfer for restoring finger extension?

. Flexor carpi radialis to extensor digitorum communis
. Flexor digitorum superficialis of the middle finger to extensor digitorum communis
. Pronator teres to extensor carpi radialis brevis
. Flexor carpi ulnaris to extensor digitorum communis
. Palmaris longus to extensor pollicis longus

Correct Answer & Explanation

. Flexor digitorum superficialis of the middle finger to extensor digitorum communis

Explanation

In the Boyes transfer for radial nerve palsy, the FDS of the middle finger is routed through the interosseous membrane to the EDC to restore finger extension. Pronator teres to ECRB is utilized for wrist extension, and FCR to EDC is characteristic of the Brand transfer.

Question 1099

Topic: Elbow & Forearm

A 45-year-old construction worker presents with the inability to actively extend his thumb, index, and middle fingers after sustaining a midshaft humerus fracture 6 months ago. EMG shows no evidence of reinnervation. A decision is made to proceed with tendon transfers. If the Pronator Teres (PT) is transferred to the Extensor Carpi Radialis Brevis (ECRB) to restore wrist extension, which of the following combinations is most commonly used to restore finger and thumb extension?

. Flexor Carpi Radialis (FCR) to Extensor Digitorum Communis (EDC); Palmaris Longus (PL) to Extensor Pollicis Longus (EPL)
. Flexor Carpi Ulnaris (FCU) to EDC; FCR to EPL
. Flexor Digitorum Superficialis (FDS) of the ring finger to EDC; FDS of the middle finger to EPL
. Brachioradialis (BR) to EDC; PL to EPL
. FCR to EPL; PL to EDC

Correct Answer & Explanation

. Flexor Carpi Radialis (FCR) to Extensor Digitorum Communis (EDC); Palmaris Longus (PL) to Extensor Pollicis Longus (EPL)

Explanation

The most common tendon transfers for a high radial nerve palsy are the PT to ECRB (to restore wrist extension), the FCR to the EDC (to restore finger extension), and the PL to the EPL (to restore thumb extension). The FCR is generally preferred over the FCU for finger extension to preserve the FCU's critical role in the dart-throwing motion and strong grip.

Question 1100

Topic: Elbow & Forearm

A 32-year-old male presents with a high radial nerve palsy following a humeral shaft fracture 8 months ago. He has no clinically detectable nerve recovery. For restoration of wrist extension, finger extension, and thumb extension, which set of tendon transfers represents the classic Brand transfer?

. Pronator teres to extensor carpi radialis brevis, flexor carpi radialis to extensor digitorum communis, palmaris longus to extensor pollicis longus
. Pronator teres to extensor carpi radialis brevis, flexor carpi ulnaris to extensor digitorum communis, palmaris longus to extensor pollicis longus
. Flexor carpi ulnaris to extensor carpi radialis brevis, flexor carpi radialis to extensor digitorum communis, palmaris longus to extensor pollicis longus
. Pronator teres to extensor carpi radialis longus, flexor carpi radialis to extensor digitorum communis, palmaris longus to extensor pollicis longus
. Brachioradialis to extensor carpi radialis brevis, flexor carpi ulnaris to extensor digitorum communis, palmaris longus to extensor pollicis longus

Correct Answer & Explanation

. Pronator teres to extensor carpi radialis brevis, flexor carpi radialis to extensor digitorum communis, palmaris longus to extensor pollicis longus

Explanation

The classic Brand tendon transfer for high radial nerve palsy utilizes the pronator teres for wrist extension (ECRB), the flexor carpi radialis for finger extension (EDC), and the palmaris longus for thumb extension (EPL). Transferring to the ECRB rather than the ECRL prevents an unacceptable radial deviation during wrist extension.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page