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Question 1

Topic: Nerve & Tendon

During diagnostic elbow arthroscopy, which of the following nerves is at the greatest risk for injury:

. Ulnar nerve
. Median nerve
. Radial nerve
. Posterior interosseous nerve
. Anterior interosseous nerve

Correct Answer & Explanation

. Radial nerve


Explanation

The radial nerve is at the greatest risk for injury during elbow arthroscopy. Injury usually occurs during creation of the anterolateral portal.

Question 2

Topic: Nerve & Tendon
Which of the following elbow arthroscopic portals is correctly matched to the nerve at risk during portal creation?
. Anteromedial portal - ulnar nerve
. Anteromedial portal - radial nerve
. Posterior portal - ulnar nerve
. Anterolateral portal - median nerve
. Posterior portal - radial nerve

Correct Answer & Explanation

. Anteromedial portal - ulnar nerve


Explanation

Incorrect placement of the anterolateral portal places the radial nerve at risk. Incorrect placement of the anteromedial portal places the median and ulnar nerves at risk. The posterior portal is not associated with neural injury.

Question 3

Topic: Nerve & Tendon

During elbow arthroscopy, the proximal anteromedial portal is established approximately 2 cm proximal and 1 cm anterior to the medial epicondyle. Which nerve is at greatest risk of injury during the establishment of this portal?

. Median nerve
. Radial nerve
. Medial antebrachial cutaneous nerve
. Ulnar nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Medial antebrachial cutaneous nerve


Explanation

The medial antebrachial cutaneous nerve (MACN) is at the greatest risk of injury when establishing the anteromedial and proximal anteromedial portals. The median nerve is further anterior, and the ulnar nerve is posterior to the medial epicondyle.

Question 4

Topic: Nerve & Tendon

The proximal anterolateral portal is frequently used as an initial viewing portal in elbow arthroscopy. It is established 2 cm proximal and 1 cm anterior to the lateral epicondyle. This portal places which of the following nerves at highest risk?

. Radial nerve
. Posterior interosseous nerve
. Lateral antebrachial cutaneous nerve
. Median nerve
. Ulnar nerve

Correct Answer & Explanation

. Radial nerve


Explanation

The proximal anterolateral portal places the radial nerve at risk, as it lies an average of 3 to 7 mm from the portal tract. The joint should be distended with fluid prior to portal placement to displace the radial nerve anteriorly.

Question 5

Topic: Nerve & Tendon

A 42-year-old mechanic presents with chronic lateral elbow pain radiating down the dorsal forearm. Pain is severe with resisted middle finger extension. Tenderness is noted 4 cm distal to the lateral epicondyle. What is the most likely site of nerve compression?

. Ligament of Struthers
. Arcade of Struthers
. Arcade of Frohse
. Lacertus fibrosus
. Osborne's fascia

Correct Answer & Explanation

. Arcade of Frohse


Explanation

The clinical picture describes Radial Tunnel Syndrome. The most common site of compression of the posterior interosseous nerve (PIN) in the radial tunnel is the Arcade of Frohse (the proximal edge of the superficial head of the supinator).

Question 6

Topic: Nerve & Tendon

When creating the standard anteromedial portal for elbow arthroscopy, the ulnar nerve is located at what approximate average distance from the correct portal placement?

. 5 mm
. 15 mm
. 25 mm
. 40 mm
. 50 mm

Correct Answer & Explanation

. 25 mm


Explanation

The standard anteromedial portal is typically placed 2 cm distal and 2 cm anterior to the medial epicondyle. At this location, the ulnar nerve is safely posterior, an average of 22 to 25 mm away from the portal.

Question 7

Topic: Nerve & Tendon

A 38-year-old female presents with aching pain in the volar proximal forearm and paresthesias in the thumb, index, and middle fingers. Symptoms are worsened by resisted forearm pronation, but not by wrist flexion. Which nerve is compressed, and at what structure?

. Median nerve at the pronator teres
. Posterior interosseous nerve at the arcade of Frohse
. Ulnar nerve at the cubital tunnel
. Anterior interosseous nerve at the pronator quadratus
. Median nerve at the carpal tunnel

Correct Answer & Explanation

. Median nerve at the pronator teres


Explanation

The patient has Pronator Syndrome, characterized by median nerve compression in the proximal forearm. Pain with resisted pronation specifically implicates the two heads of the pronator teres as the site of compression.

Question 8

Topic: Nerve & Tendon

When establishing the proximal anteromedial portal during elbow arthroscopy, the joint should be distended and the elbow flexed to 90 degrees. This specific portal places which of the following nerves at the greatest risk of injury?

. Median nerve
. Ulnar nerve
. Posterior interosseous nerve
. Medial antebrachial cutaneous nerve
. Radial nerve

Correct Answer & Explanation

. Medial antebrachial cutaneous nerve


Explanation

The proximal anteromedial portal is created approximately 2 cm proximal and 2 cm anterior to the medial epicondyle. It places the medial antebrachial cutaneous nerve (MABCN) at highest risk, as the nerve lies an average of 1-2 mm from the portal tract.

Question 9

Topic: Nerve & Tendon

A 50-year-old typist presents with medial elbow pain radiating to the ring and small fingers. Examination shows a positive Tinel's sign at the cubital tunnel and a positive Froment's sign. Which structure is the most common site of compression for this pathology?

. Arcade of Struthers
. Osborne's ligament
. Medial intermuscular septum
. Arcade of Frohse
. Two heads of the pronator teres

Correct Answer & Explanation

. Osborne's ligament


Explanation

Cubital tunnel syndrome is the most common ulnar nerve entrapment neuropathy at the elbow. The most frequent site of compression is at the cubital tunnel retinaculum, also known as Osborne's ligament.

Question 10

Topic: Nerve & Tendon

A 42-year-old mechanic complains of chronic, aching pain over the dorsal aspect of the proximal forearm. Pain is exacerbated by resisted extension of the middle finger with the elbow extended, but there is no motor weakness. What is the most likely site of neural compression?

. Ligament of Struthers
. Arcade of Frohse
. Carpal tunnel
. Cubital tunnel
. Guyon's canal

Correct Answer & Explanation

. Arcade of Frohse


Explanation

The presentation is classic for radial tunnel syndrome, a compressive neuropathy of the deep branch of the radial nerve causing pain without motor loss. The Arcade of Frohse (the proximal edge of the superficial supinator muscle) is the most common site of compression.

Question 11

Topic: Nerve & Tendon

A 28-year-old carpenter experiences deep, aching forearm pain that worsens with activity. He notes occasional numbness in his thumb, index, and middle fingers, but specifically denies night pain. Examination reveals pain with resisted forearm pronation. This presentation is characteristic of compression of which nerve?

. Radial nerve
. Ulnar nerve
. Anterior interosseous nerve
. Median nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Median nerve


Explanation

Pronator syndrome involves compression of the median nerve in the proximal forearm, leading to aching pain exacerbated by resisted pronation. It is distinguished clinically from carpal tunnel syndrome by the absence of night pain.

Question 12

Topic: Nerve & Tendon

A 22-year-old collegiate baseball pitcher reports medial elbow pain during the late cocking and early acceleration phases of throwing. On physical examination, pain is reproduced when a valgus stress is applied to the elbow while rapidly extending it from 120 to 30 degrees of flexion. This test is most sensitive for evaluating which of the following structures?

. Flexor-pronator mass
. Ulnar nerve
. Anterior bundle of the UCL
. Posterior bundle of the UCL
. Transverse bundle of the UCL

Correct Answer & Explanation

. Flexor-pronator mass


Explanation

The moving valgus stress test is highly sensitive and specific for insufficiency of the anterior bundle of the ulnar collateral ligament (UCL). Pain is typically maximal between 120 and 70 degrees of elbow flexion.

Question 13

Topic: Nerve & Tendon

During an elbow arthroscopy, the surgeon establishes the proximal anteromedial portal. This portal is typically placed 2 cm proximal and 1 cm anterior to the medial epicondyle. Which nerve is at greatest risk during the establishment of this portal if the scalpel is plunged too deeply?

. Median nerve
. Ulnar nerve
. Radial nerve
. Medial antebrachial cutaneous nerve
. Posterior interosseous nerve

Correct Answer & Explanation

. Medial antebrachial cutaneous nerve


Explanation

The medial antebrachial cutaneous nerve (MABC) is the most superficial structure at risk when establishing the anteromedial and proximal anteromedial portals. The median nerve is also at risk but is situated deeper and more laterally.

Question 14

Topic: Nerve & Tendon

During an in situ ulnar nerve decompression for severe cubital tunnel syndrome, an anomalous muscle is found crossing the ulnar nerve from the medial olecranon to the medial epicondyle. What is the name of this anomalous muscle?

. Palmaris longus
. Flexor carpi radialis brevis
. Gantzer's muscle
. Anconeus epitrochlearis
. Brachialis accessory slip

Correct Answer & Explanation

. Anconeus epitrochlearis


Explanation

The anconeus epitrochlearis is an anomalous muscle present in up to 11% of the population. It spans from the medial epicondyle to the olecranon, replacing the Osborne ligament, and can be a cause of cubital tunnel syndrome.

Question 15

Topic: Nerve & Tendon

When performing a two-incision distal biceps tendon repair, which of the following structures is at the highest risk of injury during the creation of the posterolateral approach through the extensor mass?

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

Correct Answer & Explanation

. Posterior interosseous nerve


Explanation

In a two-incision technique for distal biceps repair, creating the posterolateral approach requires dissecting through the extensor musculature. The posterior interosseous nerve (PIN) is at significant risk if the forearm is not fully pronated during this step.

Question 16

Topic: Nerve & Tendon

During a single-incision anterior approach for a distal biceps tendon repair, aggressive lateral retraction of the soft tissues places which of the following nerves at the highest risk?

. Median nerve
. Ulnar nerve
. Lateral antebrachial cutaneous nerve
. Posterior interosseous nerve
. Medial antebrachial cutaneous nerve

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve


Explanation

The lateral antebrachial cutaneous nerve (LABCN) runs superficially in the lateral aspect of the antecubital fossa. It is highly susceptible to neurapraxia or transection from excessive lateral retraction during single-incision biceps repairs.

Question 17

Topic: Nerve & Tendon

Which of the following anatomic structures is the most common site of compression in radial tunnel syndrome?

. Ligament of Struthers
. Arcade of Frohse
. Lacertus fibrosus
. Arcade of Osborne
. Guyon's canal

Correct Answer & Explanation

. Arcade of Frohse


Explanation

The Arcade of Frohse, formed by the proximal aponeurotic edge of the superficial head of the supinator muscle, is the most frequent site of posterior interosseous nerve compression in radial tunnel syndrome.

Question 18

Topic: Nerve & Tendon

Following severe elbow trauma, a patient undergoes open contracture release via a lateral column approach. Which of the following nerves must be protected anteriorly when elevating the brachialis off the joint capsule?

. Radial nerve
. Posterior interosseous nerve
. Median nerve
. Ulnar nerve
. Musculocutaneous nerve

Correct Answer & Explanation

. Radial nerve


Explanation

During the lateral column procedure for elbow release, the radial nerve courses anterior to the radiocapitellar joint. It must be carefully protected as the brachialis muscle is elevated off the anterior capsule.

Question 19

Topic: Nerve & Tendon

A 28-year-old manual laborer presents with medial elbow pain and a snapping sensation during flexion and extension, accompanied by intermittent numbness in his ring and small fingers. Ultrasonography is most likely to demonstrate subluxation of the ulnar nerve along with which other structure?

. Medial head of the triceps
. Lateral head of the triceps
. Long head of the triceps
. Brachialis
. Pronator teres

Correct Answer & Explanation

. Medial head of the triceps


Explanation

Snapping triceps syndrome occurs when the medial head of the triceps subluxates over the medial epicondyle during elbow flexion. It frequently displaces the ulnar nerve concurrently, precipitating cubital tunnel symptoms.

Question 20

Topic: Nerve & Tendon

During surgical decompression for cubital tunnel syndrome, the ulnar nerve is traced distally into the proximal forearm. Which structure bridges the two heads of the flexor carpi ulnaris (FCU) and represents a common site of deep compression?

. Arcade of Struthers
. Medial intermuscular septum
. Osborne's ligament
. Lacertus fibrosus
. Ligament of Struthers

Correct Answer & Explanation

. Osborne's ligament


Explanation

Osborne's ligament (the cubital tunnel retinaculum) forms the roof of the cubital tunnel, bridging the humeral and ulnar heads of the flexor carpi ulnaris. It is a primary site of entrapment for the ulnar nerve.