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9. Shoulder and Elbow MCQs

Practice Set 148 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 2941

Topic: Elbow & Forearm
A 70-year-old sedentary patient presents with a Mason-Johnston Type III radial head fracture with severe comminution. He is not keen on extensive surgery. What is a reasonable management option to consider, accepting potential trade-offs?
. Open reduction and internal fixation (ORIF)
. Radial head replacement
. Radial head excision
. Primary elbow arthrodesis
. Conservative management with a long arm cast

Correct Answer & Explanation

. Radial head excision

Explanation

For elderly, sedentary patients with severely comminuted radial head fractures (Type III or IV) who are not candidates for ORIF or do not desire more extensive surgery like radial head replacement, radial head excision can be a reasonable option. While it carries the risk of proximal radial migration and DRUJ issues, in low-demand individuals, it can provide pain relief and improve motion with acceptable functional outcomes.

Question 2942

Topic: 9. Shoulder and Elbow

A Mason-Johnston Type I radial head fracture typically involves:

. More than 2mm displacement
. Comminution of the articular surface
. A non-displaced crack or small articular depression
. Associated elbow dislocation
. Mechanical block to forearm rotation

Correct Answer & Explanation

. A non-displaced crack or small articular depression

Explanation

A Mason-Johnston Type I radial head fracture is characterized by a non-displaced crack or a minimally displaced (less than 2mm) small articular depression. There is typically no mechanical block to forearm rotation. Displaced fractures, comminution, and elbow dislocations are features of higher-grade Mason-Johnston types.

Question 2943

Topic: Elbow & Forearm

Which type of implant is generally preferred for radial head replacement in an acute fracture setting?

. Monoblock polyethylene implants
. Bipolar metallic implants
. Modular metallic implants
. Silicone implants
. Ceramic implants

Correct Answer & Explanation

. Modular metallic implants

Explanation

Modular metallic implants are generally preferred for radial head replacement in acute fracture settings. They allow for independent adjustment of head size, stem diameter, and neck length, enabling the surgeon to precisely restore radial length, provide stability, and optimize contact with the capitellum. Monoblock implants offer less versatility. Bipolar implants have been used but have less favorable long-term outcomes than modular designs. Silicone implants are generally reserved for rheumatoid arthritis or reconstructive procedures, not acute fractures, and have issues with wear. Ceramic implants are less common for radial head.

Question 2944

Topic: 9. Shoulder and Elbow

What is the primary role of the radial head in elbow stability?

. To prevent valgus stress on the elbow
. To prevent varus stress on the elbow
. To act as a secondary stabilizer against valgus stress and to provide longitudinal stability to the forearm
. To serve as the primary attachment for the biceps brachii
. To guide pronation and supination

Correct Answer & Explanation

. To act as a secondary stabilizer against valgus stress and to provide longitudinal stability to the forearm

Explanation

The radial head serves as a secondary stabilizer against valgus stress at the elbow, acting as a bony buttress, especially when the medial collateral ligament (MCL) is compromised. Critically, it also provides longitudinal stability to the forearm, maintaining the length relationship between the radius and ulna, which is essential for DRUJ stability and overall forearm mechanics. While it articulates to allow pronation/supination, its primary role instabilityis as a secondary valgus stabilizer and longitudinal load bearer.

Question 2945

Topic: Elbow & Forearm

When assessing a radial head fracture, what radiographic view is essential to evaluate the relationship between the radial head and capitellum and to identify potential mechanical blocks?

. Anteroposterior (AP) view of the elbow
. Lateral view of the elbow
. Oblique views (e.g., radiocapitellar view)
. Internal rotation view
. External rotation view

Correct Answer & Explanation

. Oblique views (e.g., radiocapitellar view)

Explanation

While AP and lateral views are standard, oblique views (specifically, the radiocapitellar view, also known as the radial head-capitellum view or Greenspan view) are crucial for thoroughly evaluating radial head fractures. These views help to unmask subtle displacement, depression, or mechanical blocks that might be obscured on standard AP or lateral projections, by rotating the forearm. They provide an 'en face' view of the radial head articular surface.

Question 2946

Topic: Elbow & Forearm

A 35-year-old female presents with a Mason-Johnston Type II radial head fracture with 2mm displacement but no mechanical block. She is able to fully pronate and supinate. What is the most appropriate initial management?

. Open reduction and internal fixation (ORIF)
. Radial head replacement
. Sling immobilization for 1 week followed by early active range of motion
. Radial head excision
. Long arm cast for 4 weeks

Correct Answer & Explanation

. Sling immobilization for 1 week followed by early active range of motion

Explanation

For a Mason-Johnston Type II radial head fracture with minimal displacement (2mm) andno mechanical blockto forearm rotation, non-operative management with a brief period of immobilization (e.g., 1 week in a sling for comfort) followed by early active range of motion is often appropriate. Surgical intervention (ORIF, replacement, excision) is indicated if there's significant displacement, comminution, mechanical block, or associated instability. A long arm cast would lead to unnecessary stiffness.

Question 2947

Topic: 9. Shoulder and Elbow

What is the significance of a coronoid process fracture in the context of a radial head fracture and elbow dislocation?

. It indicates a simple elbow dislocation.
. It typically suggests a stable elbow after reduction.
. It is a key component of the 'terrible triad' and signifies increased instability.
. It only affects pronation-supination.
. It is a contraindication to radial head replacement.

Correct Answer & Explanation

. It is a key component of the 'terrible triad' and signifies increased instability.

Explanation

A coronoid process fracture, especially when combined with a radial head fracture and elbow dislocation, is a critical component of the 'terrible triad' injury. Its presence signifies significant elbow instability. The coronoid is a key anterior stabilizer of the elbow; a fracture compromises this stability, increasing the risk of recurrent dislocation. Its presence does not contraindicate radial head replacement; rather, both may need to be addressed to restore stability.

Question 2948

Topic: Elbow & Forearm

Which of the following describes the 'safe zone' for screw placement in the radial head when performing ORIF?

. The anterior 90-degree arc of the radial head
. The medial aspect adjacent to the coronoid
. The area that does not articulate with the capitellum or ulna throughout the arc of forearm rotation
. The posterior aspect, directly opposite the radial tuberosity
. The lateral-most aspect, adjacent to the lateral epicondyle

Correct Answer & Explanation

. The area that does not articulate with the capitellum or ulna throughout the arc of forearm rotation

Explanation

The 'safe zone' for hardware placement in the radial head refers to the area that does not articulate with the capitellum or the lesser sigmoid notch of the ulna throughout the full range of pronation and supination. This zone is typically a 110-degree arc on the radial head, often described as the posterolateral aspect when the forearm is in neutral. Placing hardware outside this zone risks impingement, pain, and loss of motion.

Question 2949

Topic: Elbow & Forearm

What is the main advantage of using headless compression screws for fixation of radial head fractures?

. They are easier to remove if complications arise.
. They provide superior rotational stability compared to plates.
. They can be countersunk beneath the articular surface, reducing hardware prominence and impingement.
. They allow for earlier weight-bearing.
. They are significantly cheaper than other implants.

Correct Answer & Explanation

. They can be countersunk beneath the articular surface, reducing hardware prominence and impingement.

Explanation

Headless compression screws are advantageous for radial head fractures because they can be fully countersunk beneath the articular cartilage. This minimizes the risk of hardware prominence, which can lead to impingement on the capitellum or trochlea during forearm rotation, causing pain and limiting motion. They provide good compression but not necessarily superior rotational stability compared to plates. They are not always easier to remove or allow for earlier weight-bearing uniquely. Cost is not the primary surgical driver.

Question 2950

Topic: 9. Shoulder and Elbow

What complication is specifically addressed by the 'safe zone' concept in radial head fracture fixation?

. Non-union of the fracture
. Infection
. Hardware impingement on the capitellum or ulna
. Neurological injury to the PIN
. Elbow stiffness due to capsular contracture

Correct Answer & Explanation

. Hardware impingement on the capitellum or ulna

Explanation

The 'safe zone' for hardware placement directly addresses the risk of hardware impingement on the capitellum during elbow flexion-extension or on the lesser sigmoid notch of the ulna during forearm rotation. Placing screws or plates outside this non-articulating zone can lead to pain, crepitus, and mechanical block, necessitating hardware removal or revision surgery. While non-union and infection are complications, the safe zone is specifically for impingement.

Question 2951

Topic: 9. Shoulder and Elbow

Which factor is most predictive of persistent elbow stiffness after a radial head fracture?

. Patient's age
. Gender
. Severity of the initial injury (e.g., comminution, associated dislocation)
. Tobacco smoking status
. Pre-existing hypertension

Correct Answer & Explanation

. Severity of the initial injury (e.g., comminution, associated dislocation)

Explanation

The severity of the initial injury, including fracture comminution, associated ligamentous injuries, and especially concomitant elbow dislocation (as seen in terrible triad injuries), is the most significant predictor of persistent elbow stiffness. These severe injuries often involve extensive soft tissue damage, prolonged immobilization, and a higher risk of heterotopic ossification, all contributing to stiffness. While age and smoking can influence healing, the injury severity itself is paramount.

Question 2952

Topic: Elbow & Forearm

When performing ORIF of a radial head fracture, what type of approach may risk the posterolateral rotatory stability if not carefully repaired?

. Anterior (Henry) approach
. Medial approach
. Posterolateral (Kocher) approach
. Direct posterior approach
. Ulnar collateral ligament approach

Correct Answer & Explanation

. Posterolateral (Kocher) approach

Explanation

The posterolateral (Kocher) approach, while commonly used and safe for the PIN, involves detaching or splitting the anconeus muscle and reflecting the supinator. If the lateral collateral ligament complex, particularly the lateral ulnar collateral ligament (LUCL) origin, is compromised or not meticulously repaired during closure (or if it was already injured), it can destabilize the elbow against posterolateral rotatory forces. Care must be taken to repair the posterior capsule and anconeus for stability.

Question 2953

Topic: 9. Shoulder and Elbow

What is the primary concern with a retained, unreduced, or unaddressed radial head fragment causing a mechanical block to forearm rotation?

. Increased risk of infection
. Progressive ulnar nerve palsy
. Chronic pain and functional limitation due to restricted motion
. Development of heterotopic ossification
. Accelerated elbow arthritis

Correct Answer & Explanation

. Chronic pain and functional limitation due to restricted motion

Explanation

A retained, unreduced, or unaddressed radial head fragment causing a mechanical block to forearm rotation will inevitably lead to chronic pain and significant functional limitation due to restricted elbow and forearm range of motion. This impingement prevents smooth articulation and prevents the return of normal function. While long-term arthritis might develop, and HO is a risk, the immediate and primary concern is the mechanical blockage. Ulnar nerve palsy and infection are less directly related to the mechanical block itself.

Question 2954

Topic: Elbow & Forearm

In pediatric radial head fractures, what specific management consideration is crucial due to the open physis?

. Immediate radial head replacement
. Aggressive ORIF to prevent growth arrest
. Emphasis on conservative management and remodeling potential, especially for radial neck fractures
. Routine radial head excision
. Long-term antibiotic prophylaxis

Correct Answer & Explanation

. Emphasis on conservative management and remodeling potential, especially for radial neck fractures

Explanation

In pediatric radial head (and especially radial neck) fractures, conservative management is often emphasized due to the significant remodeling potential of the growing bone. Surgical intervention is typically reserved for highly displaced fractures or those with severe mechanical blocks. Radial head replacement or excision is rarely performed in children due to the presence of the open physis and potential for growth disturbance. Aggressive ORIF should be avoided if possible to prevent physeal injury, and long-term antibiotics are irrelevant.

Question 2955

Topic: 9. Shoulder and Elbow

A 50-year-old male with a history of recurrent elbow dislocations presents with a comminuted radial head fracture. Which of the following would be an appropriate prophylactic measure to consider against heterotopic ossification (HO)?

. Strict bed rest for 2 weeks
. High-dose oral corticosteroids
. Post-operative radiotherapy (e.g., 700 cGy single dose)
. Continuous passive motion (CPM) for 6 hours daily
. Vitamin D supplementation

Correct Answer & Explanation

. Post-operative radiotherapy (e.g., 700 cGy single dose)

Explanation

For high-risk patients (e.g., those with recurrent dislocations, severe comminution, associated head injury, or previous HO) undergoing elbow surgery, prophylactic measures against heterotopic ossification (HO) are often considered. Post-operative radiotherapy (typically a single dose of 700 cGy within 72 hours of surgery) and/or NSAIDs (like indomethacin) are the most evidence-based options to reduce the incidence and severity of HO. Strict bed rest is detrimental. Corticosteroids are not a primary HO prophylaxis. CPM is for motion, not HO prevention specifically. Vitamin D is not relevant to HO prophylaxis.

Question 2956

Topic: Elbow & Forearm

What clinical test helps assess lateral ulnar collateral ligament (LUCL) integrity in the context of an elbow injury suspected of posterolateral rotatory instability?

. Valgus stress test
. Varus stress test
. Pivot shift test of the elbow (e.g., gravity-assisted posterior drawer)
. Milking maneuver
. Cozen's test

Correct Answer & Explanation

. Pivot shift test of the elbow (e.g., gravity-assisted posterior drawer)

Explanation

The pivot shift test of the elbow (often performed gravity-assisted or with a specific maneuver to apply valgus and supination moment) is used to assess for posterolateral rotatory instability (PLRI), which is primarily caused by injury to the lateral ulnar collateral ligament (LUCL). Valgus stress tests the MCL, varus tests the LCL complex broadly (including LUCL but less specific for PLRI), milking maneuver tests MCL, and Cozen's test is for lateral epicondylitis.

Question 2957

Topic: 9. Shoulder and Elbow

A 60-year-old male undergoes ORIF of a radial head fracture. Two weeks post-op, he develops persistent pain, warmth, redness, and swelling in the elbow, with fever. Which diagnostic test is most appropriate to confirm the suspected complication?

. Electromyography (EMG)
. MRI of the elbow
. Elbow arthrocentesis for culture and cell count
. CT scan of the elbow
. Plain radiographs to check implant position

Correct Answer & Explanation

. Elbow arthrocentesis for culture and cell count

Explanation

The described symptoms (pain, warmth, redness, swelling, fever) are highly suggestive of a post-operative infection. The most appropriate diagnostic test to confirm an intra-articular infection is an elbow arthrocentesis to aspirate synovial fluid for Gram stain, cell count with differential, and bacterial culture. This provides definitive microbiological diagnosis. While imaging (MRI/CT) can show signs of infection, fluid analysis is gold standard. EMG is for nerve issues. Radiographs would only show obvious hardware complications or severe osteomyelitis, not early infection.

Question 2958

Topic: Elbow & Forearm

Which of the following surgical complications is specifically related to the removal of the radial head?

. Posterior interosseous nerve palsy
. Heterotopic ossification
. Proximal migration of the radius
. Ulnar nerve irritation
. Infection

Correct Answer & Explanation

. Proximal migration of the radius

Explanation

Proximal migration of the radius is a specific complication related to radial head excision. The radial head contributes to longitudinal forearm stability. Its removal without replacement, especially if the interosseous membrane is also compromised, allows the radius to migrate proximally, leading to changes in forearm mechanics, DRUJ incongruity, and often chronic wrist pain and dysfunction. While other complications can occur, proximal migration is characteristic of radial head excision.

Question 2959

Topic: Elbow & Forearm

What is the most common cause of early post-operative stiffness following radial head fracture fixation?

. Infection
. Nerve injury
. Hardware prominence and impingement
. Aseptic loosening
. Non-union

Correct Answer & Explanation

. Hardware prominence and impingement

Explanation

Early post-operative stiffness following radial head fracture fixation is very commonly caused by hardware prominence and impingement. If screws or plates are not properly countersunk or are placed outside the 'safe zone,' they can impinge on the capitellum or ulna during motion, causing pain and restricting range of motion. While infection, nerve injury, and non-union can cause issues, mechanical impingement is a leading cause of early stiffness directly related to fixation.

Question 2960

Topic: Elbow & Forearm

What is the most crucial step in managing an Essex-Lopresti lesion involving a radial head fracture?

. Sling immobilization for 6 weeks
. Excision of the radial head without replacement
. Restoration of radial length and stabilization of the DRUJ (typically with radial head replacement)
. Isolated repair of the interosseous membrane
. Primary elbow arthrodesis

Correct Answer & Explanation

. Restoration of radial length and stabilization of the DRUJ (typically with radial head replacement)

Explanation

The most crucial step in managing an Essex-Lopresti lesion is the restoration of radial length and stabilization of the distal radio-ulnar joint (DRUJ). This is typically achieved with a radial head replacement. Simply excising the radial head would exacerbate the proximal migration and DRUJ instability. Isolated repair of the interosseous membrane is often insufficient without addressing radial length. Sling immobilization and arthrodesis are not appropriate for this severe, unstable injury pattern.

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