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9. Shoulder and Elbow MCQs

Practice Set 191 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 3801

Topic: 9. Shoulder and Elbow

During an extended deltopectoral approach to the shoulder, the cephalic vein is identified. To minimize bleeding and preserve its venous drainage, the cephalic vein should ideally be retracted in which direction, and what is its anatomic rationale?

. Medially with the pectoralis major, because it is tethered by branches from the thoracoacromial trunk.
. Laterally with the deltoid, because its primary venous tributaries drain from the deltoid muscle.
. Medially with the deltoid, because it runs deep to the clavipectoral fascia.
. Laterally with the pectoralis major, to protect the lateral pectoral nerve.
. Inferiorly, because it empties directly into the basilic vein.

Correct Answer & Explanation

. Laterally with the deltoid, because its primary venous tributaries drain from the deltoid muscle.

Explanation

The cephalic vein lies in the deltopectoral groove and should be retracted laterally with the deltoid during the approach. This is because it receives the majority of its delicate venous tributaries from the deltoid muscle.

Question 3802

Topic: Elbow & Forearm

In a patient with an irreversible high radial nerve palsy, which of the following is the most standard and biomechanically reliable tendon transfer to restore wrist extension?

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

Correct Answer & Explanation

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

Explanation

The classic transfer for restoring wrist extension in a radial nerve palsy is the Pronator Teres (PT) to the Extensor Carpi Radialis Brevis (ECRB). The ECRB is chosen over the ECRL because its central insertion at the base of the third metacarpal provides balanced wrist extension, whereas ECRL insertion results in radial deviation.

Question 3803

Topic: 9. Shoulder and Elbow

During clinical evaluation of a patient with recurrent shoulder instability, the apprehension test is performed with the arm abducted to 90 degrees and externally rotated. Which ligamentous structure is the primary static restraint to anterior translation in this specific position?

. Superior glenohumeral ligament (SGHL)
. Middle glenohumeral ligament (MGHL)
. Anterior band of the inferior glenohumeral ligament (IGHL)
. Coracohumeral ligament
. Posterior band of the inferior glenohumeral ligament (IGHL)

Correct Answer & Explanation

. Anterior band of the inferior glenohumeral ligament (IGHL)

Explanation

The anterior band of the inferior glenohumeral ligament (IGHL) is the primary static stabilizer against anterior and inferior translation of the humeral head when the arm is in 90 degrees of abduction and external rotation (the typical position for anterior dislocation). The SGHL and coracohumeral ligament restrict inferior translation with the arm at the side. The MGHL prevents anterior translation with the arm in 45 degrees of abduction.

Question 3804

Topic: 9. Shoulder and Elbow

A 75-year-old male complains of severe right shoulder pain and inability to actively raise his arm above 45 degrees. Radiographs demonstrate severe glenohumeral osteoarthritis with high-riding humeral head and an acromiohumeral interval of 3 mm. MRI confirms a massive, retracted, irreparable rotator cuff tear. What is the best surgical option?

. Total shoulder arthroplasty
. Arthroscopic superior capsular reconstruction
. Latissimus dorsi tendon transfer
. Reverse total shoulder arthroplasty
. Hemiarthroplasty

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

This patient has rotator cuff tear arthropathy with pseudoparalysis (inability to actively elevate the arm). A reverse total shoulder arthroplasty is indicated as it bypasses the deficient rotator cuff by medializing and lowering the center of rotation, allowing the deltoid to initiate and maintain arm elevation.

Question 3805

Topic: 9. Shoulder and Elbow

A 72-year-old woman with a chronic massive, irreparable rotator cuff tear presents with severe pain and active forward elevation to only 45 degrees (pseudoparalysis). Her axillary nerve is intact. She is scheduled for a reverse total shoulder arthroplasty (rTSA). What is the primary biomechanical advantage provided by this implant design to restore active elevation?

. Lateralizes and elevates the center of rotation
. Lateralizes and lowers the center of rotation
. Medializes and elevates the center of rotation
. Medializes and lowers the center of rotation
. Maintains anatomic center of rotation but increases the joint volume

Correct Answer & Explanation

. Medializes and lowers the center of rotation

Explanation

The Grammont design principles of a reverse total shoulder arthroplasty (rTSA) rely on moving the center of rotation of the glenohumeral joint medially and inferiorly. Medializing the center of rotation recruits more of the deltoid fibers for elevation, while lowering the center of rotation tensions the deltoid, significantly increasing its moment arm. This allows the deltoid to effectively compensate for the deficient rotator cuff.

Question 3806

Topic: 9. Shoulder and Elbow

A 72-year-old female presents with severe shoulder pain and inability to actively elevate her arm above 30 degrees. Passive range of motion is full. MRI reveals a massive, retracted, full-thickness tear of the supraspinatus and infraspinatus with Goutallier stage 4 fatty infiltration. What is the most appropriate surgical treatment?

. Arthroscopic debridement and subacromial decompression
. Reverse total shoulder arthroplasty
. Anatomic total shoulder arthroplasty
. Latissimus dorsi tendon transfer
. Arthroscopic primary rotator cuff repair

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

This patient exhibits pseudoparalysis secondary to a massive, irreparable rotator cuff tear with severe fatty infiltration (Goutallier stage 4). Reverse total shoulder arthroplasty is the treatment of choice in an elderly patient to restore active forward elevation.

Question 3807

Topic: 9. Shoulder and Elbow

A 60-year-old male with a known massive, irreparable rotator cuff tear develops progressive superior migration of the humeral head and advanced glenohumeral osteoarthritis. He has pseudoparalysis with active elevation only up to 40 degrees. What is the most reliable surgical option for this patient?

. Arthroscopic superior capsular reconstruction
. Shoulder hemiarthroplasty
. Anatomic total shoulder arthroplasty
. Reverse total shoulder arthroplasty
. Latissimus dorsi tendon transfer

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

The patient has severe rotator cuff tear arthropathy (Hamada classification) with pseudoparalysis. Reverse total shoulder arthroplasty is the treatment of choice, as it medializes and distalizes the center of rotation, recruiting the deltoid to restore forward elevation.

Question 3808

Topic: 9. Shoulder and Elbow

A 55-year-old female with poorly controlled type II diabetes presents with global restriction of shoulder motion. She is diagnosed with primary adhesive capsulitis. Contracture of which specific anatomical structure is primarily responsible for her profound loss of external rotation with the arm at the side?

. Coracoacromial ligament
. Coracohumeral ligament
. Middle glenohumeral ligament
. Inferior glenohumeral ligament
. Posterior capsule

Correct Answer & Explanation

. Coracohumeral ligament

Explanation

In adhesive capsulitis, the rotator interval structures become profoundly contracted. The coracohumeral ligament (CHL), a major component of the rotator interval, acts as the primary restraint to external rotation when the arm is adducted at the side. The inferior glenohumeral ligament restrains external rotation when the arm is abducted to 90 degrees.

Question 3809

Topic: Shoulder Pathology

A 25-year-old motorcyclist sustains a traction injury to his right brachial plexus. Clinical examination shows a flail right arm, Horner syndrome (ptosis, miosis, anhidrosis), and paralysis of the rhomboids and serratus anterior. These findings strongly suggest an injury at which specific anatomical level?

. Post-ganglionic nerve roots
. Pre-ganglionic nerve roots
. Upper trunk
. Posterior cord
. Medial cord

Correct Answer & Explanation

. Pre-ganglionic nerve roots

Explanation

Horner syndrome (indicating T1 sympathetic ganglion involvement) and paralysis of muscles innervated by root-level branches (dorsal scapular and long thoracic nerves) indicate a severe pre-ganglionic root avulsion injury. This level of injury is typically not amenable to direct nerve repair.

Question 3810

Topic: Shoulder Arthroplasty & Arthritis

A 72-year-old with pseudoparalysis and severe rotator cuff tear arthropathy is indicated for a reverse total shoulder arthroplasty (RTSA). Which biomechanical alteration explains the success of RTSA in restoring forward elevation?

. It medializes and inferiorly displaces the center of rotation, tensioning the deltoid
. It lateralizes and superiorly displaces the center of rotation
. It relies heavily on an intact supraspinatus for overhead mechanics
. It restores the anatomical neck-shaft angle of the native humerus
. It shifts the center of rotation to the anatomic center of the humeral head

Correct Answer & Explanation

. It medializes and inferiorly displaces the center of rotation, tensioning the deltoid

Explanation

RTSA shifts the center of rotation medially and inferiorly. This effectively lengthens the deltoid lever arm and increases its resting tension, allowing the deltoid to compensate for the deficient rotator cuff.

Question 3811

Topic: 9. Shoulder and Elbow

A patient presents with neck pain radiating to the lateral forearm and thumb, associated with weakness in elbow flexion and wrist extension. The brachioradialis reflex is diminished. Which cervical nerve root is most likely compressed?

. C4
. C5
. C6
. C7
. C8

Correct Answer & Explanation

. C6

Explanation

The C6 nerve root provides sensation to the lateral forearm and thumb. Motor innervation includes the wrist extensors (ECRL, ECRB) and elbow flexors (biceps, brachioradialis). The brachioradialis reflex is mediated primarily by the C6 nerve root. C5 affects the deltoid and biceps reflex. C7 affects the triceps, wrist flexion, and finger extension.

Question 3812

Topic: Elbow & Forearm
A 35-year-old female sustains a Monteggia fracture-dislocation. According to the Bado classification, a Type I injury consists of an ulnar diaphyseal fracture combined with which of the following?
. Anterior dislocation of the radial head
. Posterior dislocation of the radial head
. Lateral dislocation of the radial head
. Fracture of the radial head without dislocation
. Distal radioulnar joint dislocation

Correct Answer & Explanation

. Anterior dislocation of the radial head

Explanation

The Bado classification describes Monteggia fractures based on the direction of radial head dislocation. Type I (most common) is an anterior dislocation of the radial head with an anteriorly angulated ulnar fracture. Type II is posterior. Type III is lateral. Type IV involves fractures of both the radius and ulna with an anterior radial head dislocation.

Question 3813

Topic: 9. Shoulder and Elbow

A patient with the most common human chondrodysplasia presents for orthopedic evaluation. Based on the clinical photograph provided, which combination of physical findings is most characteristic of this condition?



. Lumbar kyphosis, elbow hypermobility, and genu valgum
. Exaggerated lumbar lordosis, limitation of elbow extension, and genu varum
. Thoracic scoliosis, limited shoulder abduction, and genu varum
. Exaggerated lumbar lordosis, limitation of knee extension, and genu valgum
. Cervical kyphosis, elbow hypermobility, and pes planus

Correct Answer & Explanation

. Exaggerated lumbar lordosis, limitation of elbow extension, and genu varum

Explanation

Correct Answer: Exaggerated lumbar lordosis, limitation of elbow extension, and genu varumAs seen in the clinical image and described in the text, patients with achondroplasia typically present with exaggerated lumbar lordosis, limitation of elbow extension and rotation, and genu varum. Hyperextension of the knees and most other joints is also common.

Question 3814

Topic: 9. Shoulder and Elbow

The image below compares a patient with a specific skeletal dysplasia to an age-matched individual of normal stature. Which of the following statements accurately describes the anthropometric differences seen in this condition?



. The trunk is significantly shorter than normal, while the limbs are of normal length
. There is no difference in trunk height, but the chest and shoulders are narrower
. Both the trunk and limbs are proportionally shortened
. The trunk is longer than normal, compensating for severe limb shortening
. The chest is significantly wider, leading to a barrel-chest deformity

Correct Answer & Explanation

. There is no difference in trunk height, but the chest and shoulders are narrower

Explanation

Correct Answer: There is no difference in trunk height, but the chest and shoulders are narrowerAchondroplasia is a disproportionate short-limb dwarfism. As demonstrated in the comparative clinical image, there is no significant difference in the height of the trunk between an achondroplastic patient and a normal individual; however, the chest and shoulders are notably narrower.

Question 3815

Topic: 9. Shoulder and Elbow

A 5-year-old child presents to the orthopedic clinic. Clinical photographs are shown below. Examination of the upper extremities in this patient is most likely to reveal which of the following findings?


. Cubitus valgus with hypermobility
. Limitation of elbow extension and rotation
. Dislocation of the radial head
. Madelung deformity

Correct Answer & Explanation

. Limitation of elbow extension and rotation

Explanation

Correct Answer: Limitation of elbow extension and rotationThe clinical images demonstrate a patient with achondroplasia, characterized by exaggerated lumbar lordosis and genu varum. A classic upper extremity finding in these patients is the limitation of elbow extension and rotation, despite hyperextension being common in most other joints like the knees.

Question 3816

Topic: 9. Shoulder and Elbow

A 12-year-old boy with achondroplasia is evaluated for upper extremity joint mobility. Which of the following joint abnormalities is most commonly observed in this patient population?

. Limited elbow extension
. Shoulder instability
. Wrist flexion contractures
. Limited metacarpophalangeal flexion
. Distal radioulnar joint subluxation

Correct Answer & Explanation

. Limited elbow extension

Explanation

Patients with achondroplasia typically experience limited elbow extension and supination due to structural changes in the distal humerus and radial head. Despite this limitation, it rarely causes significant functional impairment.

Question 3817

Topic: 9. Shoulder and Elbow

A 74-year-old female presents with chronic right shoulder pain and an inability to actively elevate her arm above 45 degrees. Radiographs demonstrate severe glenohumeral joint space narrowing and superior migration of the humeral head, articulating with the acromion. A reverse total shoulder arthroplasty (RTSA) is planned. The biomechanical advantage of this prosthesis relies primarily on the function of which of the following muscles to achieve active elevation?

. Supraspinatus
. Infraspinatus
. Deltoid
. Subscapularis
. Teres minor

Correct Answer & Explanation

. Deltoid

Explanation

Correct Answer: C. DeltoidReverse total shoulder arthroplasty (RTSA) is indicated for rotator cuff tear arthropathy, where a massive, irreparable rotator cuff tear leads to superior migration of the humeral head and pseudoparalysis. The RTSA design reverses the normal anatomy by placing a glenosphere on the glenoid and a concave cup on the humerus. This medializes and distalizes the center of rotation, significantly increasing the moment arm and resting tension of the deltoid muscle. This allows the deltoid to initiate and maintain active shoulder elevation even in the absence of a functional supraspinatus.

Question 3818

Topic: 9. Shoulder and Elbow

A 72-year-old female undergoes a reverse total shoulder arthroplasty (RTSA) for severe rotator cuff tear arthropathy. Which of the following best describes the biomechanical alteration achieved by this implant design to restore active shoulder elevation?

. Lateralization of the center of rotation to increase the moment arm of the deltoid
. Medialization and distalization of the center of rotation to increase the deltoid moment arm and tension
. Superior translation of the center of rotation to recruit the intact subscapularis
. Anatomic restoration of the glenohumeral joint line to optimize rotator cuff remnant function
. Increased retroversion of the glenoid component to prevent anterior escape

Correct Answer & Explanation

. Medialization and distalization of the center of rotation to increase the deltoid moment arm and tension

Explanation

Correct Answer: Medialization and distalization of the center of rotation to increase the deltoid moment arm and tensionThe reverse total shoulder arthroplasty (RTSA) is designed to compensate for a deficient rotator cuff. By placing the glenosphere on the native glenoid and the concave articular surface on the humerus, the center of rotation is medialized and distalized compared to the native anatomy. This significantly increases the moment arm of the deltoid muscle and tensions its fibers, allowing the deltoid to act as the primary elevator of the shoulder without the need for a functioning supraspinatus to provide a compressive fulcrum.

Question 3819

Topic: 9. Shoulder and Elbow

A 74-year-old female with a massive, irreparable rotator cuff tear and severe glenohumeral osteoarthritis undergoes a reverse total shoulder arthroplasty (RTSA). Which of the following best describes the primary biomechanical advantage provided by this specific implant design to restore active forward elevation?

. Lateralization and superior translation of the center of rotation
. Medialization and distalization of the center of rotation
. Anatomic restoration of the glenohumeral joint line
. Increased tensioning of the remaining intact subscapularis
. Medialization and proximalization of the center of rotation

Correct Answer & Explanation

. Medialization and distalization of the center of rotation

Explanation

Correct Answer: Medialization and distalization of the center of rotationThe reverse total shoulder arthroplasty (RTSA), based on the Grammont design principles, fundamentally alters the biomechanics of the shoulder to compensate for a deficient rotator cuff. By placing a glenosphere on the native glenoid and a concave cup on the proximal humerus, the center of rotation is medialized and distalized. Medialization decreases the torque on the glenoid component (reducing loosening risk) and recruits more deltoid muscle fibers for elevation. Distalization tensions the deltoid muscle, significantly increasing its moment arm and allowing it to act as the primary elevator of the arm in the absence of a functioning supraspinatus.

Question 3820

Topic: 9. Shoulder and Elbow

A 72-year-old female undergoes a reverse total shoulder arthroplasty (RTSA) for severe rotator cuff tear arthropathy. By reversing the normal anatomical concavity and convexity of the glenohumeral joint, this implant alters the biomechanics of the shoulder. Which of the following best describes the primary biomechanical advantage of this prosthesis?

. It lateralizes the center of rotation, increasing the moment arm of the supraspinatus
. It medializes and distalizes the center of rotation, increasing the moment arm of the deltoid
. It superiorly translates the center of rotation, increasing the tension on the remaining rotator cuff
. It anteriorly translates the center of rotation, improving subscapularis function
. It anatomically restores the center of rotation, relying on the coracoacromial arch for stability

Correct Answer & Explanation

. It medializes and distalizes the center of rotation, increasing the moment arm of the deltoid

Explanation

Correct Answer: B (It medializes and distalizes the center of rotation, increasing the moment arm of the deltoid)The reverse total shoulder arthroplasty (RTSA) was designed by Paul Grammont specifically for patients with a deficient rotator cuff. By placing a convex glenosphere on the native glenoid and a concave cup on the proximal humerus, the center of rotation of the shoulder joint is medialized and distalized. This biomechanical shift significantly increases the moment arm of the deltoid muscle and recruits more of its anterior and posterior fibers to assist in elevation. Consequently, the deltoid can compensate for the absent supraspinatus, allowing the patient to actively elevate the arm.

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