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9. Shoulder and Elbow MCQs

Practice Set 16 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 301

Topic: Elbow & Forearm

A 40-year-old male sustained a mid-shaft humerus fracture with an associated high radial nerve palsy. After 6 months of observation and serial EMG testing, there is no clinical or electrical evidence of reinnervation. To restore strong, central wrist extension, what is the most common and reliable tendon transfer performed?

. Pronator teres (PT) to Extensor Carpi Radialis Brevis (ECRB)
. Flexor Carpi Ulnaris (FCU) to Extensor Digitorum Communis (EDC)
. Flexor Carpi Radialis (FCR) to Extensor Pollicis Longus (EPL)
. Palmaris Longus (PL) to Extensor Carpi Radialis Longus (ECRL)
. Flexor Digitorum Superficialis (FDS) to Extensor Indicis Proprius (EIP)

Correct Answer & Explanation

. Pronator teres (PT) to Extensor Carpi Radialis Brevis (ECRB)

Explanation

For radial nerve palsy, the Pronator Teres (PT) is most commonly transferred to the Extensor Carpi Radialis Brevis (ECRB) to restore strong, centralized wrist extension. Transfer to the ECRL is typically avoided as it leads to excessive radial deviation.

Question 302

Topic: Elbow & Forearm

When surgically managing a "terrible triad" injury of the elbow, a systematic approach to repair is required to restore stability. According to standard protocols, what is the generally recommended sequence of repair from deep to superficial?

. Coronoid, radial head, lateral collateral ligament (LCL)
. Lateral collateral ligament (LCL), radial head, coronoid
. Radial head, coronoid, lateral collateral ligament (LCL)
. Medial collateral ligament (MCL), coronoid, radial head
. Radial head, lateral collateral ligament (LCL), coronoid

Correct Answer & Explanation

. Coronoid, radial head, lateral collateral ligament (LCL)

Explanation

The standard surgical approach for a terrible triad injury builds stability from inside out (deep to superficial). The sequence is fixation of the coronoid fracture, followed by radial head repair or replacement, and finally repair of the lateral collateral ligament (LCL) complex.

Question 303

Topic: 9. Shoulder and Elbow

Which of the following conditions is most likely to present with shoulder pain and Horner's syndrome due to apical lung tumor involvement?

. Rotator cuff tendinopathy.
. Adhesive capsulitis.
. Cervical radiculopathy (C5-C6).
. Pancoast tumor.
. Thoracic outlet syndrome.

Correct Answer & Explanation

. Pancoast tumor.

Explanation

Correct Answer: DA Pancoast tumor is an apical lung tumor that can invade the brachial plexus (causing shoulder and arm pain), ribs, and sympathetic chain (leading to Horner's syndrome: ptosis, miosis, anhidrosis). While the other conditions can cause shoulder pain, only a Pancoast tumor specifically accounts for the combination of shoulder pain and Horner's syndrome in this context. Cervical radiculopathy would cause dermatomal/myotomal pain and weakness, but not Horner's syndrome. Thoracic outlet syndrome involves neurovascular compression but typically lacks Horner's syndrome.

Question 304

Topic: 9. Shoulder and Elbow

An 84-year-old female presents after a fall onto her outstretched hand. You are asked to describe her shoulder X-ray. Which of the following views is most critical for definitively diagnosing a posterior glenohumeral dislocation when an AP view shows a 'lightbulb' sign?

. AP external rotation
. Scapular Y view
. Axillary view
. West Point view
. Stryker notch view

Correct Answer & Explanation

. Axillary view

Explanation

Correct Answer: CThe axillary view is the gold standard for assessing glenohumeral joint congruity and confirming the direction of dislocation (anterior or posterior). While the 'lightbulb' sign on an AP view is suggestive of posterior dislocation, it is not definitive. The Scapular Y view can indicate posterior dislocation if the humeral head is posterior to the glenoid, but it's a sagittal view. The West Point and Stryker notch views are specific for glenoid rim defects or Hill-Sachs lesions, respectively, not primary dislocation diagnosis.

Question 305

Topic: 9. Shoulder and Elbow

An 84-year-old woman presents with long-standing shoulder pain and weakness, with active elevation limited to 60 degrees. Her X-ray shows superior migration of the humeral head, acromial erosion, and significant glenohumeral joint space narrowing. Which of the following is the most likely diagnosis?

. Primary glenohumeral osteoarthritis
. Calcium pyrophosphate deposition disease
. Rotator cuff arthropathy
. Adhesive capsulitis
. Seronegative spondyloarthropathy

Correct Answer & Explanation

. Rotator cuff arthropathy

Explanation

Correct Answer: CRotator cuff arthropathy (RCA) is characterized by chronic, massive rotator cuff tears leading to superior migration of the humeral head, resulting in direct articulation between the humeral head and the acromion. This pathological contact causes secondary degenerative changes, including acromial erosion, glenohumeral joint space narrowing (typically superiorly), and often extensive osteophyte formation. Primary glenohumeral osteoarthritis usually shows concentric or inferior joint space narrowing without significant superior migration. CPPD can cause degenerative changes but not typically with this degree of superior migration. Adhesive capsulitis shows no significant radiographic findings. Seronegative spondyloarthropathies would show erosive changes, often with sacroiliitis, but not the specific pattern of RCA.

Question 306

Topic: 9. Shoulder and Elbow

An X-ray of an 84-year-old lady's shoulder shows significant inferomedial glenohumeral joint space narrowing, subchondral sclerosis, and large inferior osteophytes. There is no evidence of superior migration of the humeral head. Which diagnosis is most consistent with these findings?

. Rotator cuff tear arthropathy
. Calcium pyrophosphate deposition disease
. Primary glenohumeral osteoarthritis
. Septic arthritis
. Avascular necrosis of the humeral head

Correct Answer & Explanation

. Primary glenohumeral osteoarthritis

Explanation

Correct Answer: CPrimary glenohumeral osteoarthritis (GHOA) typically presents with inferomedial joint space narrowing, subchondral sclerosis, and significant osteophyte formation, particularly inferiorly (humeral head and glenoid). Crucially, there is no superior migration of the humeral head, differentiating it from rotator cuff tear arthropathy. CPPD can mimic OA but often shows chondrocalcinosis. Septic arthritis would show rapid joint destruction, effusion, and possibly periarticular osteopenia, less typically prominent osteophytes. Avascular necrosis would show subchondral collapse, crescent sign, and eventual secondary OA.

Question 307

Topic: 9. Shoulder and Elbow

When describing the shoulder X-ray of an elderly patient, you note an apparent non-union of the acromion. Which specific view would be most crucial to confirm an os acromiale and differentiate it from an acute fracture?

. AP internal rotation
. Axillary view
. Outlet view
. Zanca view
. Transthoracic view

Correct Answer & Explanation

. Outlet view

Explanation

Correct Answer: CThe outlet view (or supraspinatus outlet view) is optimal for evaluating the acromial morphology, including the presence of an os acromiale, by projecting the acromion en face. An os acromiale is a developmental failure of fusion of the acromial apophyses. While other views might incidentally show it, the outlet view provides the best profile. The Zanca view is specific for the AC joint. Axillary view is for glenohumeral congruity. Transthoracic is for humeral shaft.

Question 308

Topic: 9. Shoulder and Elbow

A 'Grashey view' is requested for an 84-year-old female's shoulder. What is the primary purpose of this specific projection?

. To visualize the subacromial space
. To profile the AC joint
. To obtain a true anteroposterior projection of the glenohumeral joint
. To assess the integrity of the rotator cuff
. To detect posterior glenohumeral subluxation

Correct Answer & Explanation

. To obtain a true anteroposterior projection of the glenohumeral joint

Explanation

Correct Answer: CThe Grashey view is a 'true AP' view of the glenohumeral joint, achieved by internally rotating the patient approximately 30-45 degrees to align the glenoid parallel to the X-ray beam. This eliminates overlap of the humeral head and glenoid, allowing for accurate assessment of joint space and articulation. While rotator cuff integrity cannot be assessed directly, its sequelae (e.g., superior migration) are better appreciated.

Question 309

Topic: 9. Shoulder and Elbow

On an AP internal rotation view of an 84-year-old woman's shoulder, which anatomical landmark is best visualized en face?

. Greater tuberosity
. Lesser tuberosity
. Bicipital groove
. Surgical neck
. Acromial undersurface

Correct Answer & Explanation

. Lesser tuberosity

Explanation

Correct Answer: BThe AP internal rotation view brings the lesser tuberosity into profile, facing medially. The greater tuberosity is seen medially overlapping the humeral head. Conversely, the AP external rotation view profiles the greater tuberosity laterally.

Question 310

Topic: 9. Shoulder and Elbow

When reviewing an AP external rotation view of an elderly patient's shoulder, which structure is typically seen in profile laterally on the humeral head?

. Lesser tuberosity
. Greater tuberosity
. Glenoid fossa
. Coracoid process
. Acromion

Correct Answer & Explanation

. Greater tuberosity

Explanation

Correct Answer: BThe AP external rotation view rotates the humerus externally, bringing the greater tuberosity into profile on the lateral aspect of the humeral head. The lesser tuberosity is then positioned anteriorly and medially, often superimposing on the humeral head.

Question 311

Topic: 9. Shoulder and Elbow

A 72-year-old female presents with pseudoparalysis of the shoulder and advanced cuff tear arthropathy. A reverse total shoulder arthroplasty (rTSA) is planned. Which of the following best describes the biomechanical principle of a standard Grammont-style reverse shoulder arthroplasty?

. Lateralizes and elevates the center of rotation
. Lateralizes and distalizes the center of rotation
. Medializes and distalizes the center of rotation
. Medializes and elevates the center of rotation
. Maintains the anatomic center of rotation but constrains the joint

Correct Answer & Explanation

. Medializes and distalizes the center of rotation

Explanation

A reverse total shoulder arthroplasty biomechanically medializes and distalizes the center of rotation of the glenohumeral joint. This increases the moment arm of the deltoid muscle, allowing it to compensate for the deficient rotator cuff.

Question 312

Topic: 9. Shoulder and Elbow

A 70-year-old male presents with severe shoulder pain and an inability to actively elevate his arm above 40 degrees. Radiographs demonstrate superior migration of the humeral head with severe glenohumeral osteoarthritis. A subsequent MRI confirms a massive, retracted, irreparable tear of the supraspinatus and infraspinatus tendons with fatty infiltration. Which of the following is the most appropriate surgical management?

. Arthroscopic superior capsular reconstruction
. Total shoulder arthroplasty
. Reverse total shoulder arthroplasty
. Hemiarthroplasty
. Arthroscopic debridement and biceps tenotomy

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

Reverse total shoulder arthroplasty is the treatment of choice for older patients with rotator cuff tear arthropathy and pseudoparalysis. It medializes and distalizes the center of rotation, increasing the deltoid moment arm to restore forward elevation.

Question 313

Topic: 9. Shoulder and Elbow

A 34-year-old bodybuilder feels a sudden 'pop' and tearing sensation in his anterior chest/shoulder while performing a heavy bench press. Examination reveals loss of the anterior axillary fold. If surgical repair is pursued, where is the most common site of failure that requires reattachment?

. Clavicular head origin
. Sternal head origin
. Musculotendinous junction
. Humeral insertion
. Coracoid insertion

Correct Answer & Explanation

. Humeral insertion

Explanation

Pectoralis major ruptures almost exclusively occur in young, active males performing eccentric loading exercises like the bench press. The most common location of tearing is at the tendinous insertion onto the lateral lip of the bicipital groove on the humerus.

Question 314

Topic: 9. Shoulder and Elbow

In reverse total shoulder arthroplasty, how does the design fundamentally alter the glenohumeral joint's biomechanics compared to a native shoulder to compensate for a deficient rotator cuff?

. Lateralizes and elevates the center of rotation
. Medializes and lowers the center of rotation
. Medializes and elevates the center of rotation
. Lateralizes and lowers the center of rotation
. Maintains the native center of rotation while increasing the moment arm of the deltoid

Correct Answer & Explanation

. Medializes and lowers the center of rotation

Explanation

Reverse total shoulder arthroplasty medializes and lowers the center of rotation of the glenohumeral joint. This significantly increases the moment arm and resting tension of the deltoid muscle, allowing it to initiate and maintain forward elevation.

Question 315

Topic: Shoulder Arthroplasty & Arthritis

A 68-year-old male with a massive, retracted, irreparable posterosuperior rotator cuff tear presents with pseudoparalysis of the right shoulder. Radiographs show advanced Hamada grade 4 cuff tear arthropathy. His axillary nerve and deltoid function are intact. What is the most appropriate definitive surgical intervention?

. Arthroscopic superior capsule reconstruction
. Reverse total shoulder arthroplasty
. Anatomic total shoulder arthroplasty
. Latissimus dorsi tendon transfer
. Arthroscopic debridement and biceps tenotomy

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

Reverse total shoulder arthroplasty (RTSA) is the treatment of choice for elderly patients with massive, irreparable rotator cuff tears, pseudoparalysis, and established cuff tear arthropathy. By medializing and distalizing the center of rotation, RTSA allows the intact deltoid muscle to effectively elevate the arm.

Question 316

Topic: Elbow & Forearm

A 48-year-old male presents to the emergency department after a fall onto an outstretched hand. Radiographs reveal an elbow dislocation, a comminuted radial head fracture, and a coronoid fracture. This constellation of injuries is consistent with a 'terrible triad' of the elbow. Given the inherent instability of this injury, which of the following statements best describes the primary mechanism of posterolateral rotatory instability (PLRI) in this context?

. A. Disruption of the anterior bundle of the medial collateral ligament (MCL).
. B. Avulsion of the common flexor origin from the medial epicondyle.
. C. Failure of the lateral ulnar collateral ligament (LUCL) component of the lateral collateral ligament (LCL) complex.
. D. Impingement of the olecranon in the olecranon fossa.
. E. Isolated rupture of the annular ligament.

Correct Answer & Explanation

. C. Failure of the lateral ulnar collateral ligament (LUCL) component of the lateral collateral ligament (LCL) complex.

Explanation

Correct Answer: CThe terrible triad injury involves an elbow dislocation, radial head fracture, and coronoid fracture. The inherent instability, particularly posterolateral rotatory instability (PLRI), is primarily due to the failure of the lateral ulnar collateral ligament (LUCL) component of the lateral collateral ligament (LCL) complex. The LUCL is the primary static stabilizer against varus stress and posterolateral rotatory forces. Its disruption allows the ulna to externally rotate off the trochlea, leading to the characteristic PLRI pattern.Option A (Disruption of the anterior bundle of the medial collateral ligament (MCL))is incorrect. While the MCL can be injured in terrible triads, its primary role is to resist valgus stress. Its disruption leads to valgus instability, not the primary posterolateral rotatory instability seen with LCL failure.Option B (Avulsion of the common flexor origin from the medial epicondyle)is incorrect. This injury is associated with medial epicondyle fractures or severe valgus stress injuries but is not the primary mechanism for PLRI.Option D (Impingement of the olecranon in the olecranon fossa)is incorrect. Olecranon impingement can occur in extension but is not the primary mechanism of instability in a terrible triad, which is characterized by ligamentous disruption.Option E (Isolated rupture of the annular ligament)is incorrect. While the annular ligament stabilizes the radial head, its isolated rupture does not cause the global instability and posterolateral rotation characteristic of a terrible triad. The LUCL is the key stabilizer against PLRI.

Question 317

Topic: 9. Shoulder and Elbow

During the surgical repair of a terrible triad injury, the surgeon has excised the radial head fragments and is now addressing the coronoid fracture. The fragment is small and comminuted, making direct screw fixation challenging. According to the operative sequence described in the teaching case, what is the most appropriate method to stabilize the coronoid in this scenario?

. A. Leave the coronoid fragment unaddressed and proceed with radial head replacement.
. B. Perform a suture repair of the anterior capsule to the proximal ulna at the coronoid footprint.
. C. Attempt to reattach the fragment with multiple small K-wires.
. D. Excise the coronoid fragment to prevent impingement.
. E. Apply a small locking plate to the coronoid fragment.

Correct Answer & Explanation

. B. Perform a suture repair of the anterior capsule to the proximal ulna at the coronoid footprint.

Explanation

Correct Answer: BThe teaching case explicitly states: 'Depending on coronoid fragment size, I would reduce and fix the coronoid fracture with a single screw or I would suture the anterior capsule down to the coronoid footprint using suture anchors.' If the fragment is too small to fix, suture repair of the anterior capsule to the proximal ulna (coronoid footprint) is the recommended alternative to restore anterior stability.Option A (Leave the coronoid fragment unaddressed and proceed with radial head replacement)is incorrect. The coronoid is a critical anterior stabilizer. Leaving it unaddressed would result in persistent instability and poor outcomes.Option C (Attempt to reattach the fragment with multiple small K-wires)is incorrect. While K-wires can be used for some small fragments, the case specifically mentions the anterior capsule repair as the alternative when direct screw fixation is challenging due to comminution or small size. K-wires may not provide sufficient stability for a comminuted fragment and can be prone to migration.Option D (Excise the coronoid fragment to prevent impingement)is incorrect. The coronoid is a crucial stabilizer; excising it would further destabilize the elbow.Option E (Apply a small locking plate to the coronoid fragment)is incorrect. While locking plates are used for larger coronoid fractures, the question specifies a 'small and comminuted' fragment, making plate application challenging and often less effective than capsule repair in such cases, as per the teaching case's guidance.

Question 318

Topic: Elbow & Forearm

During the radial head replacement portion of a terrible triad repair, the surgeon must be meticulous to avoid 'overstuffing' the joint. What is the most significant biomechanical consequence of overstuffing the radiocapitellar joint with a radial head prosthesis?

. A. Increased risk of ulnar nerve compression.
. B. Reduced range of motion, particularly pronation and supination.
. C. Increased tension on the medial collateral ligament (MCL), leading to valgus instability.
. D. Premature wear of the capitellum.
. E. Increased tension on the lateral collateral ligament (LCL) complex, potentially leading to recurrent posterolateral rotatory instability.

Correct Answer & Explanation

. E. Increased tension on the lateral collateral ligament (LCL) complex, potentially leading to recurrent posterolateral rotatory instability.

Explanation

Correct Answer: EOverstuffing the radiocapitellar joint with a radial head prosthesis increases the length of the radius relative to the ulna. This leads to increased tension on the lateral collateral ligament (LCL) complex, which can paradoxically cause recurrent posterolateral rotatory instability (PLRI) by preventing proper seating of the ulna on the trochlea and increasing stress on the already compromised LCL. It can also lead to pain and stiffness.Option A (Increased risk of ulnar nerve compression)is incorrect. While ulnar nerve issues can occur with elbow trauma or surgery, overstuffing primarily affects joint mechanics and ligamentous tension, not directly the ulnar nerve.Option B (Reduced range of motion, particularly pronation and supination)is partially correct as overstuffing can lead to stiffness and reduced motion, but the most significant biomechanical consequence related to stability in a terrible triad is the impact on the LCL and PLRI.Option C (Increased tension on the medial collateral ligament (MCL), leading to valgus instability)is incorrect. Overstuffing primarily affects the lateral side of the elbow, increasing tension on the LCL, not the MCL.Option D (Premature wear of the capitellum)is incorrect. While improper sizing could theoretically lead to abnormal contact pressures, the primary and more immediate concern with overstuffing is the effect on joint stability and ligamentous tension, particularly the LCL.

Question 319

Topic: Elbow & Forearm

A 35-year-old construction worker sustains a terrible triad injury. During the operative repair, after addressing the radial head and coronoid, the surgeon proceeds to repair the lateral collateral ligament (LCL) complex. Which specific component of the LCL complex is most critical to repair to restore stability and prevent recurrent posterolateral rotatory instability (PLRI)?

. A. Radial collateral ligament (RCL).
. B. Annular ligament.
. C. Accessory lateral collateral ligament (ALCL).
. D. Lateral ulnar collateral ligament (LUCL).
. E. Anterior bundle of the medial collateral ligament (MCL).

Correct Answer & Explanation

. D. Lateral ulnar collateral ligament (LUCL).

Explanation

Correct Answer: DThe lateral ulnar collateral ligament (LUCL) is the primary static stabilizer against posterolateral rotatory instability (PLRI) of the elbow. It originates from the lateral epicondyle and inserts onto the supinator crest of the ulna. Its disruption allows the ulna to externally rotate off the trochlea, leading to the characteristic instability pattern seen in terrible triads. Therefore, its repair is critical for restoring stability.Option A (Radial collateral ligament (RCL))is incorrect. The RCL originates from the lateral epicondyle and blends with the annular ligament. It primarily resists varus stress but is less critical for PLRI than the LUCL.Option B (Annular ligament)is incorrect. The annular ligament encircles the radial head, stabilizing it within the radial notch of the ulna. While important for radial head stability, it is not the primary stabilizer against PLRI.Option C (Accessory lateral collateral ligament (ALCL))is incorrect. The ALCL is a variable component that originates from the lateral epicondyle and inserts onto the supinator crest, deep to the LUCL. While it contributes to stability, the LUCL is considered the primary and most consistent stabilizer against PLRI.Option E (Anterior bundle of the medial collateral ligament (MCL))is incorrect. The MCL is on the medial side of the elbow and is the primary stabilizer against valgus stress. It is not involved in preventing PLRI.

Question 320

Topic: 9. Shoulder and Elbow

After completing the internal fixation of a terrible triad injury, including coronoid repair, radial head replacement, and LCL repair, the surgeon performs a final stability assessment. Despite meticulous repair, there is still some residual instability, particularly with valgus stress and in full extension. According to the teaching case, what is the most appropriate next step to augment stability?

. A. Immediate conversion to a total elbow arthroplasty.
. B. Application of a hinged external fixator across the elbow.
. C. Re-exploration and re-repair of the lateral collateral ligament.
. D. Primary repair of the ulnar nerve to improve stability.
. E. Early mobilization without further intervention, relying on scar tissue formation.

Correct Answer & Explanation

. B. Application of a hinged external fixator across the elbow.

Explanation

Correct Answer: BThe teaching case explicitly states: 'If residual instability persists following fixation, I would consider a separate repair of the medial collateral ligament, or alternatively, I would consider augmenting the fixation by applying an external fixator across the elbow.' Given the persistent instability, especially with valgus stress (suggesting potential MCL insufficiency or overall global instability), a hinged external fixator is a recognized method to provide dynamic stability while allowing early range of motion.Option A (Immediate conversion to a total elbow arthroplasty)is incorrect. Total elbow arthroplasty is a salvage procedure for severe, unreconstructable injuries or failed previous surgeries, not a primary augmentation for residual instability after initial repair of a terrible triad.Option C (Re-exploration and re-repair of the lateral collateral ligament)is incorrect. While LCL repair is crucial, the question states that instability persists despite meticulous repair, and the instability is noted with valgus stress and in extension, which points more towards MCL involvement or global instability rather than isolated LCL failure. Re-repairing the LCL might not address the specific type of residual instability.Option D (Primary repair of the ulnar nerve to improve stability)is incorrect. The ulnar nerve is protected during surgery but does not contribute to elbow joint stability. Its repair would not address mechanical instability.Option E (Early mobilization without further intervention, relying on scar tissue formation)is incorrect. Leaving a persistently unstable elbow to heal by scar tissue alone is likely to result in chronic instability, pain, and poor functional outcomes. Augmentation is necessary.

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