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9. Shoulder and Elbow MCQs

Practice Set 123 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 2441

Topic: 9. Shoulder and Elbow
A 75-year-old woman with long-standing rheumatoid arthritis presents with debilitating right shoulder pain and an inability to lift her arm above 60 degrees. Radiographs show severe glenohumeral osteoarthritis with massive superior migration of the humeral head, articulating with the acromion. She has an intact deltoid muscle but a massive, irreparable rotator cuff tear. What is the most appropriate definitive management?
. Hemiarthroplasty
. Anatomic total shoulder arthroplasty
. Reverse total shoulder arthroplasty (RTSA)
. Superior capsular reconstruction
. Arthroscopic debridement and biceps tenotomy

Correct Answer & Explanation

. Reverse total shoulder arthroplasty (RTSA)

Explanation

The patient has severe rotator cuff tear arthropathy (Hamada stage III/IV) with pseudoparalysis and an intact deltoid. Reverse total shoulder arthroplasty (RTSA) is the gold standard for this condition. It medializes and distalizes the center of rotation, increasing the lever arm of the deltoid, thereby allowing it to substitute for the deficient rotator cuff and restore forward elevation. Anatomic total shoulder arthroplasty is contraindicated because eccentric superior loading by the uncontained humeral head would lead to early glenoid component loosening (rocking horse phenomenon).

Question 2442

Topic: Shoulder Arthroplasty & Arthritis

A 72-year-old woman presents 3 years after a reverse total shoulder arthroplasty with progressive shoulder pain. Radiographs are shown in Figure 1. What factor most contributes to the complication seen (scapular notching)?

. Superior baseplate tilt
. Inferior baseplate tilt
. Large glenosphere
. Lateralized glenosphere
. Increased humeral retroversion

Correct Answer & Explanation

. Superior baseplate tilt

Explanation

Scapular notching is a frequent complication of reverse total shoulder arthroplasty (RTSA), particularly with Grammont-style prostheses. Risk factors include superior tilt of the baseplate, high placement on the glenoid, and a medialized center of rotation. In contrast, inferior tilt, lateralization, and the use of a larger glenosphere can reduce the incidence of notching by increasing the distance between the humerus and the scapular neck during adduction.

Question 2443

Topic: Elbow & Forearm

A 45-year-old man falls onto his outstretched hand and sustains the injury shown in Figure 2. Which of the following is the most appropriate surgical sequence for managing this injury?

. Radial head fixation/replacement, LCL repair, coronoid fixation, MCL repair
. Coronoid fixation, radial head fixation/replacement, LCL repair, MCL repair (if needed)
. MCL repair, radial head fixation/replacement, coronoid fixation, LCL repair
. LCL repair, coronoid fixation, radial head fixation, MCL repair
. Radial head fixation, coronoid fixation, LCL repair

Correct Answer & Explanation

. Coronoid fixation, radial head fixation/replacement, LCL repair, MCL repair (if needed)

Explanation

The patient has sustained a terrible triad injury of the elbow (elbow dislocation, radial head fracture, and coronoid fracture). The standard surgical sequence generally progresses from deep to superficial: fixing the coronoid first (or placing the suture lasso), followed by the radial head (fixation or arthroplasty), then the lateral collateral ligament (LCL) repair. The medial collateral ligament (MCL) is only repaired if the elbow remains unstable in extension after the lateral side and bony structures have been addressed.

Question 2444

Topic: 9. Shoulder and Elbow

A 42-year-old woman sustains a highly unstable elbow injury after falling from a height. Radiographs demonstrate a posterolateral elbow dislocation associated with a comminuted radial head fracture and a type II coronoid fracture. Operative intervention is undertaken. After securely fixing the coronoid fracture and replacing the radial head with an arthroplasty component, the elbow remains unstable when brought into extension. What is the next most appropriate step in the surgical management?

. Apply a hinged external fixator
. Repair the medial collateral ligament (MCL)
. Immobilize the elbow in 90 degrees of flexion and full pronation
. Repair the lateral ulnar collateral ligament (LUCL)
. Perform a primary repair of the brachialis tendon

Correct Answer & Explanation

. Repair the lateral ulnar collateral ligament (LUCL)

Explanation

The patient has sustained a 'terrible triad' injury of the elbow. The standard, reliable surgical algorithm for this injury addresses structures from deep to superficial. The typical sequence is: 1) fixation of the coronoid fracture, 2) fixation or replacement of the radial head, and 3) repair of the lateral collateral ligament (LCL) complex, specifically the lateral ulnar collateral ligament (LUCL). If the elbow remains persistently unstable or subluxated in extension after these three steps are completed, then repair of the medial collateral ligament (MCL) or application of a hinged external fixator is indicated. In this scenario, the LUCL has not yet been addressed, making it the definitive next step.

Question 2445

Topic: 9. Shoulder and Elbow

A 72-year-old woman undergoes a reverse total shoulder arthroplasty (RTSA) for severe rotator cuff tear arthropathy. The design of the prosthesis fundamentally alters the biomechanics of the glenohumeral joint to compensate for the absent rotator cuff. According to the original Grammont design principles, how is the center of rotation (COR) of the glenohumeral joint altered compared to the native anatomic state?

. Moved superiorly and laterally
. Moved superiorly and medially
. Maintained in its anatomic position
. Moved inferiorly and laterally
. Moved inferiorly and medially

Correct Answer & Explanation

. Moved inferiorly and medially

Explanation

The Grammont design for reverse total shoulder arthroplasty relies on moving the center of rotation (COR) medially and inferiorly. Medializing the COR decreases the torque at the glenoid component-bone interface, reducing the risk of baseplate failure, and increases the number of deltoid fibers recruited for elevation. Inferiorizing the COR properly tensions the deltoid muscle, thereby increasing its resting tone and mechanical advantage, allowing the deltoid to effectively elevate the arm in the absence of a functioning supraspinatus.

Question 2446

Topic: Elbow & Forearm

In the standard surgical management of a terrible triad injury of the elbow (elbow dislocation, radial head fracture, coronoid fracture), which of the following represents the correct sequence of reconstruction to restore stability?

. Lateral ulnar collateral ligament (LUCL) repair, coronoid fixation, radial head arthroplasty, MCL repair if needed
. Coronoid fixation, radial head arthroplasty/fixation, LUCL repair, MCL repair if needed
. Radial head arthroplasty/fixation, LUCL repair, coronoid fixation, MCL repair if needed
. Medial collateral ligament (MCL) repair, coronoid fixation, radial head arthroplasty/fixation, LUCL repair
. Coronoid fixation, MCL repair, radial head arthroplasty/fixation, LUCL repair

Correct Answer & Explanation

. Coronoid fixation, radial head arthroplasty/fixation, LUCL repair, MCL repair if needed

Explanation

The standard "inside-out" sequence for repairing a terrible triad injury of the elbow is: 1) Coronoid fracture fixation or anterior capsular repair (addressing the deepest structure first), 2) Radial head fixation or replacement, and 3) Lateral ulnar collateral ligament (LUCL) repair. If the elbow remains unstable in extension after these steps, the medial collateral ligament (MCL) may be repaired or a hinged external fixator applied.

Question 2447

Topic: 9. Shoulder and Elbow

A 65-year-old man presents with persistent shoulder pain, weakness, and increased passive external rotation 6 months following an anatomic total shoulder arthroplasty (TSA). Physical examination reveals a positive belly-press test and increased passive external rotation compared to the contralateral side. Radiographs show no evidence of hardware loosening. What is the most likely cause of his symptoms?

. Glenoid component loosening
. Axillary nerve injury
. Subscapularis tendon failure
. Postoperative infection
. Supraspinatus tendon tear

Correct Answer & Explanation

. Subscapularis tendon failure

Explanation

Subscapularis failure is a known complication following anatomic total shoulder arthroplasty, especially since the tendon is typically taken down (via tenotomy, peel, or lesser tuberosity osteotomy) to gain joint access. Clinical signs include weakness in internal rotation (positive belly-press, bear-hug, or lift-off tests) and increased passive external rotation. Early recognition is crucial, as delayed repair results in poorer functional outcomes.

Question 2448

Topic: Shoulder Arthroplasty & Arthritis

A 78-year-old female with severe osteoporosis sustains a 3-part proximal humerus fracture. Due to the high risk of avascular necrosis and poor bone quality, a reverse total shoulder arthroplasty (RTSA) is performed. In this setting, healing of which of the following structures is most critical to ensure adequate functional external rotation and optimal clinical outcomes?

. Lesser tuberosity
. Greater tuberosity
. Subscapularis tendon
. Biceps long head tendon
. Coracoacromial ligament

Correct Answer & Explanation

. Greater tuberosity

Explanation

In the setting of reverse total shoulder arthroplasty (RTSA) for proximal humerus fractures, anatomic healing of the greater tuberosity is strongly associated with improved active forward elevation and external rotation. Failure of greater tuberosity healing often leads to decreased functional outcomes due to the loss of the posterior rotator cuff (infraspinatus and teres minor) acting as a force couple and external rotator.

Question 2449

Topic: Elbow & Forearm

A 7-year-old boy presents for evaluation of a left elbow deformity. He sustained a displaced supracondylar humerus fracture 2 years ago, which was treated with closed reduction and percutaneous pinning. Physical examination reveals a significant cubitus varus deformity. Which of the following statements regarding this condition is most accurate?

. It is typically a purely cosmetic deformity with no long-term functional implications.
. It is most commonly caused by post-traumatic growth arrest of the medial capitellum.
. It is usually the result of osseous malunion involving coronal plane rotation.
. It frequently leads to tardy median nerve palsy.
. Spontaneous remodeling is expected to correct the deformity by skeletal maturity.

Correct Answer & Explanation

. It is usually the result of osseous malunion involving coronal plane rotation.

Explanation

Cubitus varus ("gunstock deformity") is the most common long-term complication of supracondylar humerus fractures, occurring primarily due to malunion rather than physeal growth arrest. The malunion is typically a combination of extension, medial tilt, and internal rotation. Long-term studies have shown it can lead to functional issues, including an increased risk of lateral condyle fractures, posterolateral rotatory instability (PLRI), and tardy ulnar nerve palsy. Coronal plane deformities do not remodel with growth.

Question 2450

Topic: 9. Shoulder and Elbow

A 35-year-old man sustains a 'terrible triad' injury to his elbow. During surgical reconstruction, standard protocol is followed: the coronoid fracture is fixed and the comminuted radial head is replaced with a prosthesis. Intraoperative fluoroscopy reveals that the elbow remains unstable in extension. What is the next most appropriate step in the surgical algorithm?

. Repair of the medial collateral ligament (MCL)
. Repair of the lateral ulnar collateral ligament (LUCL)
. Application of a hinged external fixator
. Release of the common extensor origin
. Transposition of the ulnar nerve

Correct Answer & Explanation

. Repair of the lateral ulnar collateral ligament (LUCL)

Explanation

The 'terrible triad' of the elbow includes an elbow dislocation, a radial head fracture, and a coronoid process fracture. The standard surgical algorithm progresses from deep to superficial and typically involves: (1) fixation or replacement of the radial head, (2) fixation of the coronoid, and (3) repair of the lateral collateral ligament (LCL) complex, specifically the lateral ulnar collateral ligament (LUCL), to the lateral epicondyle. If the elbow remains unstable after LUCL repair, the MCL is addressed or a hinged external fixator is applied.

Question 2451

Topic: 9. Shoulder and Elbow

Reverse total shoulder arthroplasty (RTSA) is designed to alter the biomechanics of the glenohumeral joint to compensate for a massive, irreparable rotator cuff tear. Which of the following best describes the biomechanical alterations achieved with a classic Grammont-style prosthesis?

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

Correct Answer & Explanation

. Medialization and inferior translation of the center of rotation

Explanation

The classic Grammont-style reverse total shoulder arthroplasty works by medializing and distalizing (inferiorly translating) the center of rotation. Medialization limits torque at the glenoid bone-implant interface (reducing shear forces) and recruits more deltoid fibers. Inferior translation tensions the deltoid muscle, increasing its moment arm and allowing it to act as the primary elevator of the shoulder in the absence of a functional rotator cuff.

Question 2452

Topic: Elbow & Forearm

A 40-year-old bodybuilder undergoes a single-incision anterior approach for the repair of a distal biceps tendon rupture. During his first postoperative visit, he complains of numbness and tingling along the radial aspect of his forearm. Which nerve was most likely injured during the procedure, and what is the most common mechanism?

. Posterior interosseous nerve; forceful deep retractor placement
. Superficial radial nerve; entrapment in the suture anchor
. Lateral antebrachial cutaneous nerve; traction during superficial dissection
. Medial antebrachial cutaneous nerve; aberrant skin incision
. Median nerve; deep drill plunge through the posterior cortex

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve; traction during superficial dissection

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 distal biceps repair. Injury is typically due to traction or stretch from retractors during the superficial approach, as the nerve runs closely alongside the cephalic vein in the lateral subcutaneous tissue. Posterior interosseous nerve (PIN) injury is more classically associated with the two-incision technique or deep retractor placement.

Question 2453

Topic: 9. Shoulder and Elbow

A 19-year-old rugby player presents to the emergency department after a direct blow to the anteromedial shoulder. He reports shortness of breath, mild dysphagia, and right-sided neck fullness. Physical exam reveals a palpable defect over the medial clavicle. Standard radiographs are equivocal. What is the most appropriate next step in diagnostic imaging, and which surgical specialty should ideally be available on standby if closed reduction is attempted?

. MRI of the sternoclavicular joint; vascular surgery standby
. CT scan of the chest and lower neck; cardiothoracic surgery standby
. Ultrasound of the root of the neck; otolaryngology standby
. Serendipity radiograph view; general surgery standby
. MR angiogram; neurosurgery standby

Correct Answer & Explanation

. CT scan of the chest and lower neck; cardiothoracic surgery standby

Explanation

The clinical presentation is highly suspicious for a posterior sternoclavicular dislocation, which can compress posterior mediastinal structures including the trachea, esophagus, and great vessels (subclavian or innominate artery/vein). A CT scan is the imaging modality of choice to accurately assess the direction of dislocation and proximity to vascular structures. If closed reduction is attempted, it should be done in the operating room with cardiothoracic surgery available, due to the life-threatening risk of lacerating a great vessel upon reduction.

Question 2454

Topic: 9. Shoulder and Elbow

A 45-year-old man falls from a height and sustains a 'terrible triad' injury of the elbow. Which of the following describes the most appropriate sequence of surgical reconstruction to restore elbow stability?

. Coronoid fixation, radial head repair or replacement, lateral collateral ligament (LCL) repair, and medial collateral ligament (MCL) repair if still unstable
. Radial head replacement, LCL repair, coronoid fixation, MCL repair
. MCL repair, coronoid fixation, radial head repair, LCL repair
. LCL repair, radial head replacement, coronoid fixation, MCL repair
. Coronoid fixation, MCL repair, radial head repair, LCL repair

Correct Answer & Explanation

. Coronoid fixation, radial head repair or replacement, lateral collateral ligament (LCL) repair, and medial collateral ligament (MCL) repair if still unstable

Explanation

The classic 'terrible triad' of the elbow includes an elbow dislocation, radial head fracture, and coronoid fracture. The standard surgical sequence to restore elbow stability is typically performed from deep to superficial: 1) fixation of the coronoid fracture (or anterior capsule repair if the fragment is too small), 2) repair or replacement of the radial head, 3) repair of the lateral ulnar collateral ligament (LUCL/LCL complex), and 4) if the elbow remains unstable in extension after these steps, repair of the medial collateral ligament (MCL) or application of a hinged external fixator.

Question 2455

Topic: Shoulder Arthroplasty & Arthritis

The Grammont design of a reverse total shoulder arthroplasty (RTSA) alters the biomechanics of the shoulder to compensate for a massive, irreparable rotator cuff tear. Which of the following accurately describes the primary biomechanical advantage of this design?

. It medializes and superiorly translates the center of rotation, decreasing the deltoid moment arm.
. It lateralizes and inferiorly translates the center of rotation, increasing the tension on the remaining rotator cuff.
. It medializes and inferiorly translates the center of rotation, increasing the deltoid moment arm and recruiting more deltoid muscle fibers.
. It lateralizes and superiorly translates the center of rotation, maximizing the joint reaction force.
. It maintains the anatomic center of rotation but constrains the joint to prevent superior migration.

Correct Answer & Explanation

. It medializes and inferiorly translates the center of rotation, increasing the deltoid moment arm and recruiting more deltoid muscle fibers.

Explanation

The Grammont design principles for reverse total shoulder arthroplasty include medializing and inferiorly translating the center of rotation. Medialization decreases the torque on the glenoid component, reducing the risk of loosening, while inferior translation tensions the deltoid muscle. Together, these biomechanical changes significantly increase the deltoid's moment arm and recruit more of its anterior and posterior fibers, allowing the deltoid to compensate for the deficient rotator cuff and elevate the arm effectively.

Question 2456

Topic: 9. Shoulder and Elbow

A 45-year-old woman presents with vague shoulder pain and inability to elevate her arm above 90 degrees. She underwent an excisional biopsy of a posterior triangle cervical lymph node 3 months ago. On examination, the affected shoulder droops, and the scapula is translated laterally and rotated downward. Winging is exacerbated by arm abduction. Which of the following is the most appropriate surgical treatment if conservative management fails?

. Pectoralis major transfer
. Eden-Lange procedure
. Split pectoralis major transfer
. Latissimus dorsi transfer
. Lower trapezius transfer

Correct Answer & Explanation

. Eden-Lange procedure

Explanation

The clinical scenario describes a spinal accessory nerve (CN XI) palsy, which denervates the trapezius muscle, leading to lateral winging of the scapula (downward rotation and lateral translation). The Eden-Lange procedure involves transferring the levator scapulae to the acromion, and the rhomboid major and minor to the infraspinatus fossa, substituting for the paralyzed trapezius to stabilize the scapula. Pectoralis major transfer is typically used for serratus anterior palsy (medial winging).

Question 2457

Topic: 9. Shoulder and Elbow

A 40-year-old man sustains a 'terrible triad' injury to his elbow. Intraoperatively, the radial head is replaced, the coronoid fracture is fixed securely, and the lateral ulnar collateral ligament (LUCL) is repaired. On fluoroscopic examination, the elbow is noted to subluxate posteriorly when extended beyond 30 degrees of flexion. What is the most appropriate next step in management?

. Application of an articulated external fixator
. Medial collateral ligament (MCL) repair
. Immobilization in 90 degrees of flexion for 4 weeks
. Revision of the radial head arthroplasty to a larger size
. Excision of the coronoid fragment

Correct Answer & Explanation

. Medial collateral ligament (MCL) repair

Explanation

The treatment algorithm for terrible triad injuries involves systematic restoration of the anterior and lateral stabilizers (coronoid, radial head, and LUCL). If the elbow remains unstable or subluxates during terminal extension after adequately addressing these structures, the medial collateral ligament (MCL) should be repaired. An articulated external fixator is a salvage option if instability persists despite MCL repair.

Question 2458

Topic: 9. Shoulder and Elbow

A 72-year-old man presents with chronic right shoulder pain and pseudoparalysis. Radiographs reveal superior migration of the humeral head and acetabularization of the coracoacromial arch. The patient undergoes a reverse total shoulder arthroplasty (RTSA). During the procedure, the glenoid baseplate is deliberately positioned with an inferior tilt. What is the primary biomechanical rationale for this baseplate positioning?

. To increase overall deltoid tension
. To minimize the risk of inferior scapular notching
. To shift the center of rotation laterally
. To compensate for subscapularis deficiency
. To prevent anterior instability

Correct Answer & Explanation

. To minimize the risk of inferior scapular notching

Explanation

In reverse total shoulder arthroplasty (RTSA), inferior positioning and inferior tilt of the glenosphere/baseplate are utilized primarily to reduce the incidence of inferior scapular notching. Scapular notching occurs when the medial aspect of the humeral tray impinges on the inferior neck of the scapula during adduction. Inferior tilt clears the scapular neck and decreases this mechanical impingement.

Question 2459

Topic: 9. Shoulder and Elbow

A 24-year-old motorcyclist sustains a severe closed traction injury to his right brachial plexus. Clinical examination at 4 months reveals complete pan-plexus paralysis. Horner's syndrome is present. MRI demonstrates pseudomeningoceles at C8 and T1, and EMG shows denervation of the cervical paraspinal muscles. What is the most appropriate reconstructive strategy for restoring elbow flexion?

. Nerve transfer using the terminal branch of the spinal accessory nerve to the musculocutaneous nerve
. Nerve transfer using multiple intercostal nerves to the musculocutaneous nerve
. Tendon transfer using the latissimus dorsi to the biceps brachii
. Primary nerve grafting of the C5 and C6 nerve roots to the upper trunk
. Steindler flexorplasty

Correct Answer & Explanation

. Nerve transfer using multiple intercostal nerves to the musculocutaneous nerve

Explanation

The presence of Horner's syndrome, pseudomeningoceles, and denervated paraspinals indicates a pre-ganglionic pan-plexus root avulsion. Primary nerve grafting is impossible because there are no viable proximal nerve roots. Extra-plexal nerve transfers are required. Intercostal nerves (usually 3 or 4) are frequently transferred to the musculocutaneous nerve to restore elbow flexion. The spinal accessory nerve is typically prioritized for suprascapular nerve transfer for shoulder stability. Tendon transfers are not viable as all native muscles are paralyzed.

Question 2460

Topic: Elbow & Forearm

A 40-year-old man sustains a 'terrible triad' injury of the elbow consisting of a posterior elbow dislocation, a radial head fracture, and a coronoid fracture. During open surgical reconstruction, what is the generally recommended sequence of fixation to reliably restore elbow stability?

. LCL repair, then coronoid fixation, then radial head fixation
. Radial head fixation, then coronoid fixation, then MCL repair
. Coronoid fixation, then radial head repair or replacement, then LCL repair
. MCL repair, then radial head fixation, then coronoid fixation
. LCL repair, then MCL repair, then radial head replacement

Correct Answer & Explanation

. Coronoid fixation, then radial head repair or replacement, then LCL repair

Explanation

The standard surgical algorithm for terrible triad injuries builds from deep to superficial and anterior to posterior. First, the coronoid fracture is fixed or its anterior capsule repaired (restoring the anterior buttress). Second, the radial head is fixed or replaced (restoring the anterior column). Finally, the lateral collateral ligament (LCL) complex is repaired to the lateral epicondyle to restore posterolateral rotatory stability.

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