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Question 1801

Topic: Shoulder & Hip Sports

A 29-year-old volleyball player has an isolated weakness of external rotation in her dominant shoulder. Atrophy is noted over the infraspinatus fossa, while the supraspinatus muscle belly appears normal. MRI reveals a paralabral cyst. Where is the cyst most likely located?

. Suprascapular notch
. Spinoglenoid notch
. Quadrilateral space
. Triangular interval
. Subcoracoid space

Correct Answer & Explanation

. Spinoglenoid notch


Explanation

A cyst at the spinoglenoid notch compresses the terminal branch of the suprascapular nerve, resulting in isolated denervation of the infraspinatus. Compression at the suprascapular notch would affect both the supraspinatus and infraspinatus.

Question 1802

Topic: Shoulder & Hip Sports

A 28-year-old overhead athlete is diagnosed with a ganglion cyst causing nerve compression strictly at the spinoglenoid notch. Physical examination is most likely to reveal weakness in which of the following muscles?

. Supraspinatus only
. Infraspinatus only
. Supraspinatus and infraspinatus
. Teres minor and deltoid
. Subscapularis

Correct Answer & Explanation

. Infraspinatus only


Explanation

The suprascapular nerve innervates the supraspinatus prior to passing through the spinoglenoid notch. Compression at the spinoglenoid notch isolatedly affects the innervation to the infraspinatus, causing isolated external rotation weakness.

Question 1803

Topic: Shoulder & Hip Sports

A surgeon is repairing a massive rotator cuff tear involving the teres minor and encounters bleeding near the quadrilateral space. What are the anatomic borders of this space?

. Teres minor (superior), teres major (inferior), long head of triceps (medial), humerus (lateral)
. Teres major (superior), latissimus dorsi (inferior), long head of triceps (medial), humerus (lateral)
. Teres minor (superior), teres major (inferior), lateral head of triceps (medial), humerus (lateral)
. Supraspinatus (superior), infraspinatus (inferior), glenoid (medial), humerus (lateral)
. Teres minor (superior), teres major (inferior), long head of triceps (lateral), humerus (medial)

Correct Answer & Explanation

. Teres minor (superior), teres major (inferior), long head of triceps (medial), humerus (lateral)


Explanation

The quadrilateral space is bounded superiorly by the teres minor, inferiorly by the teres major, medially by the long head of the triceps, and laterally by the surgical neck of the humerus. It contains the axillary nerve and posterior circumflex humeral artery.

Question 1804

Topic: Shoulder & Hip Sports

A 28-year-old volleyball player presents with isolated weakness of the infraspinatus and vague posterior shoulder pain. An MRI reveals a paralabral cyst. Where is the most likely location of the cyst and which nerve is affected?

. Suprascapular notch compressing the axillary nerve
. Spinoglenoid notch compressing the suprascapular nerve
. Quadrilateral space compressing the axillary nerve
. Suprascapular notch compressing the suprascapular nerve
. Triangular interval compressing the radial nerve

Correct Answer & Explanation

. Spinoglenoid notch compressing the suprascapular nerve


Explanation

A cyst at the spinoglenoid notch typically compresses the suprascapular nerve after it has given off its motor branches to the supraspinatus. This distal entrapment results in isolated infraspinatus weakness with sparing of the supraspinatus.

Question 1805

Topic: Shoulder & Hip Sports

A 34-year-old weightlifter presents with isolated infraspinatus atrophy and weakness, with completely preserved supraspinatus strength and bulk. An MRI is most likely to reveal a paralabral ganglion cyst compressing the suprascapular nerve at which of the following anatomic locations?

. Suprascapular notch
. Spinoglenoid notch
. Quadrilateral space
. Triangular interval
. Rotator interval

Correct Answer & Explanation

. Spinoglenoid notch


Explanation

Compression of the suprascapular nerve at the spinoglenoid notch affects only the infraspinatus muscle. In contrast, compression at the suprascapular notch (proximal to the spinoglenoid notch) denervates both the supraspinatus and infraspinatus.

Question 1806

Topic: Shoulder & Hip Sports

A 29-year-old professional volleyball player presents with progressive weakness in external rotation of the shoulder. Examination reveals isolated atrophy of the infraspinatus muscle, while the supraspinatus is clinically normal. Where is the most likely location of nerve entrapment?

. Quadrilateral space
. Suprascapular notch
. Spinoglenoid notch
. Triangular interval
. Triangular space

Correct Answer & Explanation

. Spinoglenoid notch


Explanation

Entrapment of the suprascapular nerve at the spinoglenoid notch affects only the infraspinatus muscle. Compression at the more proximal suprascapular notch would affect both the supraspinatus and infraspinatus.

Question 1807

Topic: Shoulder & Hip Sports

A 28-year-old elite volleyball player presents with painless weakness in external rotation of the right shoulder. Physical examination reveals isolated atrophy of the infraspinatus muscle with normal bulk of the supraspinatus. An MRI is most likely to show a paralabral cyst compressing a nerve at which of the following anatomical locations?

. Quadrilateral space
. Triangular interval
. Suprascapular notch
. Spinoglenoid notch
. Spiral groove

Correct Answer & Explanation

. Spinoglenoid notch


Explanation

Compression of the suprascapular nerve at the spinoglenoid notch affects only the infraspinatus. Compression at the suprascapular notch would affect both the supraspinatus and infraspinatus muscles.

Question 1808

Topic: Shoulder & Hip Sports

A 32-year-old volleyball player presents with shoulder pain and isolated wasting of the infraspinatus muscle without supraspinatus involvement. An MRI is expected to show a paralabral cyst compressing a nerve at which of the following anatomic locations?

. Suprascapular notch
. Spinoglenoid notch
. Quadrangular space
. Triangular interval
. Triangular space

Correct Answer & Explanation

. Spinoglenoid notch


Explanation

The suprascapular nerve innervates the supraspinatus before passing through the spinoglenoid notch to innervate the infraspinatus. Entrapment at the spinoglenoid notch causes isolated infraspinatus atrophy, whereas compression at the suprascapular notch affects both muscles.

Question 1809

Topic: Shoulder & Hip Sports

A 30-year-old elite volleyball player develops progressive, isolated weakness of shoulder external rotation with no sensory deficits. Abduction strength is graded 5/5 and is symmetric to the contralateral shoulder. Given this specific clinical presentation, an entrapment neuropathy is suspected. Where is the most likely location of the nerve compression?

. Suprascapular notch
. Spinoglenoid notch
. Quadrangular space
. Triangular space
. Triangular interval

Correct Answer & Explanation

. Spinoglenoid notch


Explanation

The suprascapular nerve innervates the supraspinatus (shoulder abduction) and the infraspinatus (shoulder external rotation). Entrapment at the suprascapular notch affects BOTH muscles. Entrapment at the spinoglenoid notch (commonly due to a paralabral cyst associated with a posterior SLAP tear in overhead athletes) occurs distal to the motor branch to the supraspinatus, resulting in isolated infraspinatus atrophy and isolated external rotation weakness.

Question 1810

Topic: Shoulder & Hip Sports

During arthroscopic shoulder surgery, the rotator interval is evaluated. Which of the following correctly identifies the anatomical borders and contents of the rotator interval?

. Superiorly bounded by supraspinatus, inferiorly bounded by infraspinatus; contains long head of biceps.
. Superiorly bounded by subscapularis, inferiorly bounded by supraspinatus; contains middle glenohumeral ligament.
. Medially bounded by the coracoid process, laterally bounded by the bicipital groove; contains the short head of the biceps.
. Superiorly bounded by the coracoacromial ligament, inferiorly bounded by the supraspinatus; contains the subacromial bursa.
. Superiorly bounded by supraspinatus, inferiorly bounded by subscapularis; contains long head of biceps and coracohumeral ligament.

Correct Answer & Explanation

. Superiorly bounded by supraspinatus, inferiorly bounded by subscapularis; contains long head of biceps and coracohumeral ligament.


Explanation

The rotator interval is a triangular anatomic space in the anterosuperior shoulder. It is bounded superiorly by the anterior margin of the supraspinatus tendon, inferiorly by the superior margin of the subscapularis tendon, and medially by the base of the coracoid process. Its vital contents include the long head of the biceps tendon, the coracohumeral ligament, and the superior glenohumeral ligament.

Question 1811

Topic: Shoulder & Hip Sports

A 28-year-old elite volleyball player presents with vague posterolateral shoulder pain and isolated weakness in external rotation. Shoulder abduction strength is normal.

An MRI reveals a paralabral cyst. Based on the clinical findings of isolated infraspinatus weakness with normal supraspinatus function, at which of the following anatomic locations is the nerve compression most likely occurring?

. Suprascapular notch
. Spinoglenoid notch
. Quadrilateral space
. Triangular interval
. Scalene triangle

Correct Answer & Explanation

. Spinoglenoid notch


Explanation

The suprascapular nerve passes through the suprascapular notch, where it gives off motor branches to the supraspinatus, and then continues through the spinoglenoid notch to innervate the infraspinatus. Compression at the spinoglenoid notch (often due to a posterior labral tear and subsequent paralabral cyst) results in isolated infraspinatus denervation and external rotation weakness, sparing the supraspinatus.

Question 1812

Topic: Shoulder & Hip Sports

During an arthroscopic evaluation of a shoulder, the surgeon visualizes the rotator interval. Which of the following options correctly identifies the anatomic borders and contents of the rotator interval?

. Infraspinatus superiorly, teres minor inferiorly; containing the posterior circumflex humeral artery.
. Supraspinatus superiorly, subscapularis inferiorly; containing the middle glenohumeral ligament and axillary nerve.
. Subscapularis superiorly, pectoralis major inferiorly; containing the short head of the biceps.
. Supraspinatus superiorly, subscapularis inferiorly; containing the long head of the biceps and coracohumeral ligament.
. Coracoacromial ligament superiorly, supraspinatus inferiorly; containing the subacromial bursa.

Correct Answer & Explanation

. Supraspinatus superiorly, subscapularis inferiorly; containing the long head of the biceps and coracohumeral ligament.


Explanation

The rotator interval is a triangular space bounded superiorly by the anterior margin of the supraspinatus tendon and inferiorly by the superior margin of the subscapularis tendon. Its contents include the long head of the biceps tendon, the coracohumeral ligament, and the superior glenohumeral ligament.

Question 1813

Topic: Shoulder & Hip Sports

A 28-year-old elite volleyball player presents with insidious onset of posterior shoulder pain and isolated weakness in external rotation. An MRI reveals a paralabral cyst causing nerve compression in the quadrangular space. The space through which this compressed nerve passes is anatomically bordered by which of the following structures?

. Teres minor, teres major, long head of triceps, humerus
. Teres minor, teres major, long head of triceps, medial head of triceps
. Teres major, latissimus dorsi, long head of triceps, humerus
. Infraspinatus, teres minor, long head of triceps, humerus
. Supraspinatus, infraspinatus, teres minor, humerus

Correct Answer & Explanation

. Teres minor, teres major, long head of triceps, humerus


Explanation

The quadrangular space is bordered superiorly by the teres minor (or subscapularis when viewed anteriorly), inferiorly by the teres major, medially by the long head of the triceps, and laterally by the surgical neck of the humerus. It transmits the axillary nerve and the posterior humeral circumflex artery. Compression here leads to axillary nerve neuropathy, commonly presenting with teres minor and deltoid denervation changes.

Question 1814

Topic: Shoulder & Hip Sports

A surgeon is performing a posterior approach to the shoulder to address a locked posterior glenohumeral fracture-dislocation. To safely access the posterior joint capsule and avoid denervating the dynamic stabilizers of the shoulder, an internervous plane is developed. Which of the following describes the correct internervous plane and its respective muscle innervations?

. Between Supraspinatus (suprascapular n.) and Infraspinatus (suprascapular n.)
. Between Infraspinatus (suprascapular n.) and Teres Minor (axillary n.)
. Between Teres Minor (axillary n.) and Teres Major (lower subscapular n.)
. Between Teres Major (lower subscapular n.) and Latissimus Dorsi (thoracodorsal n.)
. Between Deltoid (axillary n.) and Triceps (radial n.)

Correct Answer & Explanation

. Between Infraspinatus (suprascapular n.) and Teres Minor (axillary n.)


Explanation

The classic posterior approach to the shoulder exploits the true internervous plane between the infraspinatus (innervated by the suprascapular nerve) and the teres minor (innervated by the axillary nerve). Retracting the infraspinatus superiorly and the teres minor inferiorly safely exposes the posterior joint capsule while protecting the critical neurovascular supply to the rotator cuff musculature.

Question 1815

Topic: Shoulder & Hip Sports

A 28-year-old overhead athlete presents with insidious onset of poorly localized posterior shoulder pain and paresthesias over the lateral aspect of the deltoid. Examination reveals isolated atrophy of the teres minor. The structure responsible for the patient's symptoms passes through a space bounded by which of the following structures?

. Teres minor, teres major, long head of triceps, and surgical neck of humerus
. Teres minor, teres major, long head of triceps, and anatomical neck of humerus
. Teres major, latissimus dorsi, long head of triceps, and shaft of humerus
. Subscapularis, coracobrachialis, short head of biceps, and humerus
. Supraspinatus, infraspinatus, subscapularis, and glenoid

Correct Answer & Explanation

. Teres minor, teres major, long head of triceps, and surgical neck of humerus


Explanation

The patient has Quadrilateral Space Syndrome, characterized by compression of the axillary nerve and posterior circumflex humeral artery. The quadrilateral space is bounded superiorly by the teres minor, inferiorly by the teres major, medially by the long head of the triceps, and laterally by the surgical neck of the humerus. Compression typically presents with posterior shoulder pain, paresthesias over the lateral deltoid, and selective atrophy of the teres minor (and occasionally the deltoid).

Question 1816

Topic: Shoulder & Hip Sports

A 32-year-old elite volleyball player complains of right shoulder pain and weakness. An MRI demonstrates a large paralabral cyst causing isolated compression at the spinoglenoid notch. Physical examination is most likely to demonstrate weakness in which of the following motions, and normal strength in which?

. Weakness in external rotation; normal abduction
. Weakness in abduction; normal external rotation
. Weakness in internal rotation; normal abduction
. Weakness in external rotation and abduction
. Weakness in forward flexion; normal internal rotation

Correct Answer & Explanation

. Weakness in external rotation; normal abduction


Explanation

The suprascapular nerve first passes through the suprascapular notch (innervating the supraspinatus) and then continues distally through the spinoglenoid notch to innervate the infraspinatus. A paralabral cyst at the spinoglenoid notch will compress only the distal portion of the nerve, resulting in isolated denervation of the infraspinatus (weakness in external rotation). Supraspinatus function (abduction) remains completely intact as its motor branches arise proximal to the cyst.

Question 1817

Topic: Shoulder & Hip Sports

A 35-year-old male undergoes a Latarjet procedure for recurrent anterior shoulder instability. Postoperatively, he has weakness in elbow flexion and decreased sensation over the lateral forearm. Which of the following anatomic structures was most likely injured during the conjoint tendon retraction?

. Axillary nerve
. Musculocutaneous nerve
. Radial nerve
. Median nerve
. Ulnar nerve

Correct Answer & Explanation

. Musculocutaneous nerve


Explanation

The musculocutaneous nerve penetrates the coracobrachialis muscle typically 5-8 cm distal to the coracoid process, though variations exist. Retraction of the conjoint tendon during the Latarjet procedure places this nerve at high risk of neuropraxia or structural injury. It provides motor innervation to the biceps brachii and brachialis (elbow flexion) and continues as the lateral antebrachial cutaneous nerve, providing sensation to the lateral forearm.

Question 1818

Topic: Shoulder & Hip Sports

A 45-year-old tennis player complains of vague posterior shoulder pain and weakness in external rotation. An MRI reveals a multilobulated paralabral cyst at the spinoglenoid notch. Which of the following muscles is most likely to exhibit isolated atrophy on physical examination or imaging?

. Supraspinatus
. Infraspinatus
. Teres minor
. Subscapularis
. Deltoid

Correct Answer & Explanation

. Infraspinatus


Explanation

The suprascapular nerve passes through the suprascapular notch (where compression affects both the supraspinatus and infraspinatus) and continues laterally and inferiorly through the spinoglenoid notch to innervate the infraspinatus. A cyst located specifically at the spinoglenoid notch compresses the nerve distal to the motor branches supplying the supraspinatus, resulting in isolated denervation, weakness, and atrophy of the infraspinatus muscle.

Question 1819

Topic: Shoulder & Hip Sports

A 42-year-old woman is evaluated for a 'frozen shoulder' (adhesive capsulitis). Surgical capsular release is considered after 6 months of failed conservative management. The surgeon plans to release the rotator cuff interval. Which of the following structures is NOT a boundary or content of the rotator cuff interval?

. Supraspinatus tendon
. Subscapularis tendon
. Coracohumeral ligament
. Middle glenohumeral ligament
. Teres minor tendon

Correct Answer & Explanation

. Coracohumeral ligament


Explanation

The rotator cuff interval is a triangular anatomic space in the anterior shoulder. Its boundaries are the anterior margin of the supraspinatus tendon (superiorly), the superior margin of the subscapularis tendon (inferiorly), and the base of the coracoid process (medially). The contents of the interval include the long head of the biceps tendon, the coracohumeral ligament (CHL), and the superior glenohumeral ligament (SGHL). The middle glenohumeral ligament (MGHL) often blends with the inferior aspect of the interval. The teres minor is located posteriorly and is not associated with the rotator cuff interval.

Question 1820

Topic: Shoulder & Hip Sports

A 24-year-old professional volleyball player presents with isolated weakness in external rotation of the shoulder. Electromyography reveals isolated denervation of the infraspinatus muscle with normal supraspinatus function. Entrapment of the affected nerve is most likely occurring at the spinoglenoid notch. Which of the following structures forms the roof of this anatomical space?

. Transverse scapular ligament
. Coracoacromial ligament
. Inferior transverse scapular ligament
. Coracoclavicular ligament
. Acromioclavicular ligament

Correct Answer & Explanation

. Inferior transverse scapular ligament


Explanation

The suprascapular nerve first passes through the suprascapular notch, under the superior transverse scapular ligament, where it innervates the supraspinatus. It then courses around the base of the scapular spine through the spinoglenoid notch, passing under the inferior transverse scapular ligament (also known as the spinoglenoid ligament), to innervate the infraspinatus. Compression at the spinoglenoid notch leads to isolated infraspinatus weakness, whereas compression at the suprascapular notch affects both the supraspinatus and infraspinatus.