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9. Shoulder and Elbow MCQs

Practice Set 159 of 197

This practice set contains high-yield board review questions covering key concepts in 9. Shoulder and Elbow. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 3161

Topic: Elbow & Forearm

A 42-year-old female presents with neck pain radiating down her left arm. Physical examination reveals a diminished brachioradialis reflex, decreased sensation over her left thumb and index finger, and weakness in wrist extension. Which cervical nerve root is most likely affected?

. C4
. C5
. C6
. C7
. C8

Correct Answer & Explanation

. C4

Explanation

The C6 nerve root innervates the brachioradialis and wrist extensors (ECRL, ECRB). A C6 radiculopathy typically presents with a diminished brachioradialis reflex and sensory changes in the thumb and index finger.

Question 3162

Topic: Shoulder Arthroplasty & Arthritis

A 72-year-old male with severe rotator cuff arthropathy and pseudoparalysis undergoes a reverse total shoulder arthroplasty (RTSA). Biomechanically, how does RTSA restore active forward elevation?

. Medializes and inferiorizes the center of rotation
. Lateralizes and superiorizes the center of rotation
. Medializes and superiorizes the center of rotation
. Lateralizes and inferiorizes the center of rotation
. Maintains the anatomic center of rotation but increases deltoid tension

Correct Answer & Explanation

. Medializes and inferiorizes the center of rotation

Explanation

RTSA shifts the center of rotation medially and inferiorly. This medialization increases the deltoid moment arm and recruits more of the anterior and posterior deltoid fibers for elevation, mechanically compensating for the deficient rotator cuff.

Question 3163

Topic: Shoulder Pathology

A 28-year-old female presents with a dull ache around her shoulder and medial scapular winging that noticeably worsens when pushing against a wall. Which nerve and muscle are most likely affected?

. Spinal accessory nerve - Trapezius
. Long thoracic nerve - Serratus anterior
. Dorsal scapular nerve - Rhomboids
. Suprascapular nerve - Supraspinatus
. Axillary nerve - Deltoid

Correct Answer & Explanation

. Spinal accessory nerve - Trapezius

Explanation

Medial scapular winging is classically caused by serratus anterior paralysis, which is innervated by the long thoracic nerve. It is often accentuated by having the patient push against a wall. In contrast, lateral winging is typically caused by trapezius paralysis (spinal accessory nerve).

Question 3164

Topic: 9. Shoulder and Elbow
A 50-year-old diabetic female presents with global restriction of active and passive shoulder range of motion. She is currently in the 'freezing' phase of adhesive capsulitis. What histologic finding is most characteristic of the glenohumeral capsule in this condition?
. Neutrophilic infiltration
. Amyloid deposition
. Fibroblastic proliferation and dense type III collagen
. Chondroid metaplasia
. Fatty infiltration

Correct Answer & Explanation

. Fibroblastic proliferation and dense type III collagen

Explanation

Adhesive capsulitis is fundamentally a fibrosing condition rather than a purely acute inflammatory one. It is characterized by fibroblastic proliferation and increased deposition of type III collagen, akin to Dupuytren's disease. There is typically no gross acute inflammatory (neutrophilic) infiltrate.

Question 3165

Topic: 9. Shoulder and Elbow

A 68-year-old male with end-stage glenohumeral osteoarthritis is being considered for an anatomic Total Shoulder Arthroplasty (TSA). Which of the following is considered an absolute contraindication for an anatomic TSA in this patient?

. Intact rotator cuff
. Glenoid retroversion of 10 degrees
. Coracoacromial ligament absence combined with a massive rotator cuff tear
. Type B1 glenoid morphology
. Biceps tendon rupture

Correct Answer & Explanation

. Intact rotator cuff

Explanation

Anatomic TSA relies on a functioning rotator cuff to dynamically maintain the humeral head centered on the glenoid. A massive, irreparable rotator cuff tear is an absolute contraindication to anatomic TSA due to the high risk of superior migration, eccentric wear, and 'rocking horse' glenoid component loosening. These patients are better treated with a Reverse TSA.

Question 3166

Topic: 9. Shoulder and Elbow

A 32-year-old competitive weightlifter feels a 'pop' and sudden pain in his anterior shoulder while performing a heavy bench press. Examination reveals loss of the anterior axillary fold and weakness in internal rotation. Which part of the pectoralis major is most commonly injured in this specific scenario?

. Clavicular head at the muscle belly
. Sternal head at the musculotendinous junction or insertion
. Sternal head at the clavicular origin
. Clavicular head at the clavicular origin
. Both heads rupture equally at their origins

Correct Answer & Explanation

. Clavicular head at the muscle belly

Explanation

Pectoralis major ruptures most commonly occur during eccentric loading (e.g., the descent phase of a bench press). Because of the twisted nature of the insertion footprint, the sternal head is under maximal tension when the arm is extended and externally rotated. The most common location of rupture is at or near the humeral insertion of the sternal head.

Question 3167

Topic: 9. Shoulder and Elbow

A 17-year-old rugby player sustains a severe lateral blow to his shoulder and presents with shortness of breath, dysphagia, and a prominent soft tissue depression at the medial end of his clavicle. What is the most appropriate next step in management?

. Immediate closed reduction in the emergency department
. Urgent CT scan of the chest/clavicle followed by reduction in the OR with cardiothoracic surgery backup
. Routine outpatient MRI of the sternoclavicular joint
. Sling immobilization for 4 weeks with delayed reconstruction
. Open reduction and internal fixation with a hook plate

Correct Answer & Explanation

. Immediate closed reduction in the emergency department

Explanation

The patient's symptoms suggest a posterior sternoclavicular dislocation, which is a medical emergency due to potential compression of the trachea, esophagus, and great vessels. An urgent CT scan is the best imaging modality. Reduction should be performed in the OR with cardiothoracic surgery available in case of devastating vascular injury during reduction.

Question 3168

Topic: 9. Shoulder and Elbow

During an anatomic dissection of the shoulder, you isolate the coracoclavicular (CC) ligaments. Which of the following correctly describes the anatomical relationship and primary biomechanical function of these ligaments?

. The conoid is medial and resists anterior translation; the trapezoid is lateral and resists superior translation
. The conoid is medial and resists superior translation; the trapezoid is lateral and resists axial compression
. The conoid is lateral and resists superior translation; the trapezoid is medial and resists anterior translation
. The conoid is lateral and resists axial compression; the trapezoid is medial and resists superior translation
. Both ligaments primarily resist posterior translation of the clavicle

Correct Answer & Explanation

. The conoid is medial and resists anterior translation; the trapezoid is lateral and resists superior translation

Explanation

The coracoclavicular ligaments consist of the conoid (medial) and trapezoid (lateral). The conoid primarily resists superior and anterior displacement of the clavicle, while the trapezoid primarily resists axial compression to the distal clavicle toward the acromion.

Question 3169

Topic: 9. Shoulder and Elbow

An 18-year-old male is injured during a rugby tackle. He presents to the trauma bay with a hoarse voice, mild stridor, and left shoulder pain. Examination reveals a visible depression at the medial aspect of the left clavicle. What is the most appropriate next step in the management of this patient?

. Closed reduction under conscious sedation in the emergency department
. MRI of the sternoclavicular joint
. CT scan of the chest and closed reduction in the OR with cardiothoracic surgery available
. Open reduction and internal fixation with a hook plate
. Sling immobilization and immediate physical therapy

Correct Answer & Explanation

. Closed reduction under conscious sedation in the emergency department

Explanation

The patient's clinical presentation (hoarse voice, stridor, medial clavicle depression) is highly suspicious for a posterior sternoclavicular (SC) joint dislocation. Posterior SC dislocations are orthopedic emergencies due to the risk of compression to the trachea, esophagus, and great vessels. A CT scan of the chest is the gold standard for diagnosis. Closed reduction should be attempted, but it must be performed in the operating room with cardiothoracic surgery backup due to the risk of catastrophic vascular injury during the reduction maneuver.

Question 3170

Topic: Shoulder Arthroplasty & Arthritis

Which of the following best describes the biomechanical alterations achieved by a Grammont-style reverse total shoulder arthroplasty compared to native shoulder anatomy?

. Medialization and superior translation of the center of rotation
. Medialization and distalization of the center of rotation
. Lateralization and superior translation of the center of rotation
. Lateralization and distalization of the center of rotation
. No change in the center of rotation

Correct Answer & Explanation

. Medialization and superior translation of the center of rotation

Explanation

The primary biomechanical advantage of a Grammont-style reverse total shoulder arthroplasty (RTSA) is the medialization and distalization of the center of rotation. Medialization recruits more anterior and posterior deltoid fibers, and distalization tensions the deltoid, thereby increasing its moment arm and efficiency to elevate the arm in the absence of a functional rotator cuff.

Question 3171

Topic: 9. Shoulder and Elbow

In patients who undergo reverse total shoulder arthroplasty, scapular notching is a well-recognized radiographic phenomenon. Which surgical modification during the procedure most effectively reduces the incidence of inferior scapular notching?

. Superior placement of the glenosphere
. Inferior tilt of the glenosphere
. Use of a smaller diameter glenosphere
. Increasing the medial offset of the humeral stem
. Decreasing the retrotorsion of the humeral stem

Correct Answer & Explanation

. Superior placement of the glenosphere

Explanation

Scapular notching occurs due to mechanical impingement of the medial humeral metaphysis against the inferior scapular neck during adduction. It can be minimized by placing the glenosphere inferiorly (creating an inferior overhang), utilizing a larger diameter glenosphere, and incorporating an inferior tilt to the baseplate. Superior placement increases the risk of notching.

Question 3172

Topic: 9. Shoulder and Elbow

A 62-year-old male with primary glenohumeral osteoarthritis is scheduled for a total shoulder arthroplasty. Preoperative CT scan demonstrates a biconcave glenoid with 20 degrees of retroversion and posterior subluxation of the humeral head. According to the Walch classification, what type of glenoid morphology is this?

. Type A1
. Type A2
. Type B1
. Type B2
. Type C

Correct Answer & Explanation

. Type A1

Explanation

The Walch classification describes glenoid morphology in osteoarthritis. Type A has a centered humeral head (A1 minor, A2 deep central erosion). Type B has posterior subluxation of the humeral head (B1 narrowing/sclerosis, B2 biconcave, B3 monoconcave with retroversion > 15 degrees). Type C represents a dysplastic glenoid with severe retroversion (> 25 degrees) but without posterior subluxation of the humerus. A biconcave glenoid with posterior subluxation is classified as Type B2.

Question 3173

Topic: 9. Shoulder and Elbow
A 50-year-old female with poorly controlled type II diabetes presents with severe, progressive stiffness and pain in her right shoulder, consistent with the "freezing" stage of adhesive capsulitis. Which of the following histologic findings is most characteristic of the glenohumeral joint capsule in this condition?
. Dense infiltration of polymorphonuclear leukocytes
. Cartilage metaplasia with osteophyte formation
. Fibroblast and myofibroblast proliferation with abundant type III collagen
. Monosodium urate crystal deposition
. Non-caseating granulomatous inflammation

Correct Answer & Explanation

. Fibroblast and myofibroblast proliferation with abundant type III collagen

Explanation

The pathophysiology of adhesive capsulitis involves an initial inflammatory response followed by a prominent fibrotic cascade. Histologic examination of the joint capsule shows dense fibrous tissue with a proliferation of fibroblasts and myofibroblasts. There is an upregulation of cytokines such as TGF-beta and PDGF, and a disorganized deposition of collagen, featuring an increased ratio of type III to type I collagen compared to a normal capsule.

Question 3174

Topic: 9. Shoulder and Elbow

A 72-year-old female presents with chronic, intractable right shoulder pain and pseudoparalysis. Radiographs reveal an acromiohumeral distance (AHD) of 3 mm and acetabularization of the coracoacromial arch, but no significant glenohumeral arthritis. According to the Hamada classification, what grade is her rotator cuff arthropathy?

. Grade 1
. Grade 2
. Grade 3
. Grade 4
. Grade 5

Correct Answer & Explanation

. Grade 1

Explanation

The Hamada classification stages rotator cuff arthropathy based on AP radiographs: Grade 1 (AHD > 6 mm), Grade 2 (AHD < 5 mm), Grade 3 (acetabularization of the acromion), Grade 4A (glenohumeral arthritis without narrowing of the AHD), Grade 4B (glenohumeral arthritis with AHD < 5 mm), and Grade 5 (humeral head collapse/osteonecrosis). The presence of acetabularization makes this Grade 3.

Question 3175

Topic: 9. Shoulder and Elbow

A 25-year-old motorcyclist presents after a high-speed collision. He has a flail upper extremity, massive swelling over the shoulder and chest wall, and absent radial and ulnar pulses. An AP radiograph shows severe lateral displacement of the scapula relative to the spinous processes. What is the most critical immediate step in the management of this condition?

. Emergent upper extremity amputation
. Arteriography and vascular surgical consultation
. Immediate open reduction and internal fixation of the clavicle
. Immediate brachial plexus exploration
. Application of a shoulder spica cast

Correct Answer & Explanation

. Emergent upper extremity amputation

Explanation

Scapulothoracic dissociation involves a complete disruption of the scapulothoracic articulation and is frequently associated with devastating subclavian/axillary vascular and brachial plexus injuries. Because of the high risk of limb loss or life-threatening hemorrhage, immediate assessment of vascular status with arteriography (or CT angiography) and vascular surgery consultation takes precedence.

Question 3176

Topic: 9. Shoulder and Elbow

A 17-year-old high school football player is tackled with a lateral compressive force to his left shoulder. He complains of left shoulder pain, dysphagia, and a choking sensation. Physical examination reveals a palpable depression at the medial end of the left clavicle. What is the most appropriate next step in management?

. Discharge home with a sling and outpatient follow-up
. Immediate closed reduction in the emergency department with procedural sedation
. CT scan of the chest and emergent closed reduction in the operating room with cardiothoracic surgery backup
. Open reduction and internal fixation with K-wires
. Excision of the medial clavicle

Correct Answer & Explanation

. Discharge home with a sling and outpatient follow-up

Explanation

The patient has a posterior sternoclavicular (SC) joint dislocation. Dysphagia and a choking sensation indicate compression of mediastinal structures (esophagus, trachea, great vessels). CT is the modality of choice for evaluation. Reduction must be performed under general anesthesia in the OR with cardiothoracic surgery backup available, due to the severe risk of great vessel injury during the reduction maneuver.

Question 3177

Topic: Shoulder Arthroplasty & Arthritis

An 68-year-old male with primary osteoarthritis of the shoulder is planned for an anatomic total shoulder arthroplasty. A preoperative CT scan reveals a biconcave glenoid with severe posterior wear and a retroversion of 20 degrees.

According to the Walch classification, what type of glenoid is this?

. Type A1
. Type A2
. Type B1
. Type B2
. Type C

Correct Answer & Explanation

. Type A1

Explanation

The Walch classification describes glenoid morphology in primary osteoarthritis. A Type B2 glenoid is characterized by a biconcave surface, posterior wear, and posterior subluxation of the humeral head, often with significant retroversion. Type B1 shows posterior subluxation but no biconcavity. Type C represents a dysplastic glenoid with severe retroversion (>25 degrees) not necessarily caused by wear.

Question 3178

Topic: Shoulder Arthroplasty & Arthritis

A 72-year-old female presents with pain and crepitus 3 years after a reverse total shoulder arthroplasty for cuff tear arthropathy. Radiographs demonstrate a radiolucent area on the scapular neck extending beyond the inferior screw of the glenoid baseplate.

According to the Sirveaux classification of scapular notching, what grade is this?

. Grade 1
. Grade 2
. Grade 3
. Grade 4
. Grade 5

Correct Answer & Explanation

. Grade 1

Explanation

Scapular notching after RTSA is evaluated using the Sirveaux classification. Grade 1: notch confined to the scapular pillar. Grade 2: notch reaches the inferior screw of the baseplate. Grade 3: notch extends over/beyond the inferior screw. Grade 4: notch extends to the central peg or central screw.

Question 3179

Topic: Shoulder Arthroplasty & Arthritis

Reverse total shoulder arthroplasty (RTSA) alters the biomechanics of the shoulder joint to compensate for a deficient rotator cuff. Which of the following best describes the biomechanical changes achieved by RTSA?

. Shifts the center of rotation superiorly and laterally
. Shifts the center of rotation inferiorly and medializes the humerus
. Increases the resting tension of the deltoid by superiorizing the humerus
. Decreases the moment arm of the deltoid muscle
. Shifts the center of rotation laterally to increase rotator cuff tension

Correct Answer & Explanation

. Shifts the center of rotation superiorly and laterally

Explanation

RTSA compensates for a massive, irreparable rotator cuff tear by moving the center of rotation medially and inferiorly. This medialization recruits more deltoid fibers, while the inferiorization lengthens the deltoid, increasing its resting tension and moment arm, allowing the deltoid to effectively elevate the arm without the help of the rotator cuff.

Question 3180

Topic: Shoulder Pathology

A 34-year-old female presents with paresthesias and pain in the medial aspect of her right forearm and hand, particularly with overhead activities. On examination, the Adson test is positive. Plain radiographs show large bilateral cervical ribs. Electromyography reveals decreased conduction velocity in the ulnar nerve distribution. Which of the following anatomical triangles is most commonly implicated in this form of Thoracic Outlet Syndrome?

. Between the anterior scalene, middle scalene, and first rib
. Between the pectoralis minor, coracoid, and rib cage
. Between the clavicle, first rib, and subclavius muscle
. Between the sternocleidomastoid, anterior scalene, and clavicle
. Between the latissimus dorsi, teres major, and humerus

Correct Answer & Explanation

. Between the anterior scalene, middle scalene, and first rib

Explanation

Neurogenic Thoracic Outlet Syndrome most commonly occurs at the interscalene triangle, which is bordered anteriorly by the anterior scalene muscle, posteriorly by the middle scalene muscle, and inferiorly by the first rib. The presence of a cervical rib narrows this space further, predisposing to brachial plexus compression.

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