Menu

Shoulder Arthroplasty & Arthritis MCQs

Practice Set 1 of 14

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

Question 1

Topic: Shoulder Arthroplasty & Arthritis

In the design and biomechanics of a reverse total shoulder arthroplasty (RTSA), moving the center of rotation medially and inferiorly achieves which of the following?

. Decreases the moment arm of the deltoid muscle
. Increases shear forces at the glenoid bone-implant interface
. Increases the tension and mechanical advantage of the deltoid muscle
. Restores normal anatomical version of the glenoid
. Allows the rotator cuff to become the primary elevator of the arm

Correct Answer & Explanation

. Increases the tension and mechanical advantage of the deltoid muscle

Explanation

RTSA medializes and distalizes the center of rotation, which increases the deltoid muscle's moment arm and tension. This allows the deltoid to effectively elevate the arm in the absence of a functioning rotator cuff.

Question 2

Topic: Shoulder Arthroplasty & Arthritis

A 72-year-old man presents with chronic shoulder pain and pseudoparalysis. Radiographs show superior migration of the humeral head and acetabularization of the acromion. He has a functioning deltoid. What is the most appropriate surgical intervention?

. Arthroscopic rotator cuff repair
. Hemiarthroplasty
. Anatomic total shoulder arthroplasty
. Reverse total shoulder arthroplasty
. Latissimus dorsi tendon transfer

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

The patient has cuff tear arthropathy with pseudoparalysis but a functioning deltoid. Reverse total shoulder arthroplasty (RTSA) is the treatment of choice, as it medializes and distalizes the center of rotation, maximizing the moment arm of the deltoid.

Question 3

Topic: Shoulder Arthroplasty & Arthritis

A 72-year-old female presents with chronic shoulder pain and pseudoparalysis. Radiographs show superior migration of the humeral head and an acromiohumeral interval of 3 mm. Which treatment provides the best predictable outcomes for this specific condition?

. Arthroscopic rotator cuff repair
. Hemiarthroplasty
. Reverse total shoulder arthroplasty
. Anatomic total shoulder arthroplasty

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

The patient has rotator cuff tear arthropathy. Reverse total shoulder arthroplasty (RTSA) is the treatment of choice because it establishes a stable center of rotation, allowing the deltoid muscle to efficiently elevate the arm.

Question 4

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 5

Topic: Shoulder Arthroplasty & Arthritis

A 74-year-old female sustains a complex 3-part proximal humerus fracture involving the surgical neck and greater tuberosity. Which of the following patient or radiographic factors most strongly supports the decision to perform a primary reverse total shoulder arthroplasty (RTSA) instead of open reduction internal fixation (ORIF)?

. Intact medial calcar length > 8 mm
. Absence of medial hinge disruption
. Pre-existing severe rotator cuff arthropathy
. Varus angulation of 10 degrees
. Non-displaced lesser tuberosity fragment

Correct Answer & Explanation

. Pre-existing severe rotator cuff arthropathy

Explanation

Reverse total shoulder arthroplasty is highly indicated for complex proximal humerus fractures in elderly patients when there is pre-existing severe rotator cuff dysfunction or arthropathy, as ORIF or hemiarthroplasty would yield poor functional results.

Question 6

Topic: Shoulder Arthroplasty & Arthritis

A 74-year-old female presents with pseudoparalysis of the right shoulder and severe pain. Radiographs reveal an acromiohumeral interval of 3 mm and severe "bone-on-bone" arthritic changes. MRI confirms a massive, retracted rotator cuff tear with grade 4 fatty infiltration of the supraspinatus and infraspinatus. What is the most appropriate surgical intervention?

. Arthroscopic rotator cuff repair with patch augmentation
. Latissimus dorsi tendon transfer
. Anatomic total shoulder arthroplasty
. Hemiarthroplasty alone
. Reverse total shoulder arthroplasty

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

Reverse total shoulder arthroplasty (RTSA) is the gold standard for rotator cuff tear arthropathy in an elderly patient with pseudoparalysis. It medializes and distalizes the center of rotation, recruiting the deltoid to elevate the arm despite the deficient rotator cuff.

Question 7

Topic: Shoulder Arthroplasty & Arthritis

A 78-year-old male with severe osteoporosis and a history of a massive, irreparable rotator cuff tear presents with a highly comminuted four-part proximal humerus fracture after a fall. He is physiologically fit for surgery and desires to regain as much function as possible. Based on the current literature and guidelines, which surgical option is MOST likely to provide predictable pain relief and functional improvement in this specific patient?

. Open reduction and internal fixation (ORIF) with a locking plate and suture augmentation.
. Hemiarthroplasty with tuberosity repair.
. Non-operative management with sling immobilization.
. Reverse total shoulder arthroplasty (RTSA).
. Intramedullary nailing.

Correct Answer & Explanation

. Reverse total shoulder arthroplasty (RTSA).

Explanation

Correct Answer: DThe patient presents with a 'highly comminuted four-part proximal humerus fracture,' 'severe osteoporosis,' and a 'massive, irreparable rotator cuff tear' in an 'elderly' patient. The text explicitly states: 'Reverse Total Shoulder Arthroplasty (RTSA) has gained significant traction, especially in elderly patients with complex PHFs, pre-existing rotator cuff dysfunction, or severe osteopenia. Multiple studies demonstrate more predictable pain relief and functional outcomes with RTSA compared to hemiarthroplasty or ORIF in this specific demographic, as it bypasses the need for tuberosity healing and relies on the deltoid for elevation.' This perfectly matches the patient's profile and desired outcome.ORIF with a locking plate (A) would be highly challenging and likely to fail given the severe comminution, severe osteoporosis, and irreparable rotator cuff tear. The ability to achieve stable fixation and tuberosity healing would be severely compromised.Hemiarthroplasty (B) has historically been an option for complex fractures in older patients, but the text notes 'outcomes can be variable, often limited by tuberosity healing and rotator cuff function.' Given the irreparable rotator cuff tear and severe osteoporosis, hemiarthroplasty would likely yield poor functional results.Non-operative management (C) for a highly comminuted four-part fracture in a patient desiring function would likely result in significant pain, malunion, and very poor function.Intramedullary nailing (E) is less common for complex PHFs and is generally not indicated for four-part fractures, especially with severe osteoporosis and rotator cuff compromise, due to difficulty controlling head rotation and potential for AVN.

Question 8

Topic: Shoulder Arthroplasty & Arthritis

A 75-year-old female with a history of severe osteoporosis sustains a displaced four-part proximal humerus fracture. The greater and lesser tuberosities are severely comminuted. To provide the most reliable restoration of active forward elevation, which surgical option is preferred?

. Nonoperative management in a sling
. Open reduction and internal fixation with a locked plate
. Hemiarthroplasty
. Reverse total shoulder arthroplasty
. Percutaneous pinning

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

Reverse total shoulder arthroplasty (RTSA) is the treatment of choice for elderly patients with complex three- or four-part proximal humerus fractures and poor bone quality. RTSA provides more reliable pain relief and functional overhead elevation compared to hemiarthroplasty, which depends heavily on tuberosity healing.

Question 9

Topic: Shoulder Arthroplasty & Arthritis

A 78-year-old female with severe rotator cuff tear arthropathy is scheduled for a reverse total shoulder arthroplasty (RTSA) via the deltopectoral approach. The surgical team positions her in the beach chair position. Which of the following is a recognized disadvantage or potential complication specifically associated with the beach chair position for this procedure?

. A. Increased risk of brachial plexus injury due to gravity working against exposure.
. B. Higher incidence of deep vein thrombosis in the operative arm.
. C. Potential for cerebral hypoperfusion, requiring meticulous blood pressure monitoring.
. D. Difficulty in achieving adequate glenoid exposure due to the patient's upright posture.
. E. Increased risk of ulnar nerve palsy in the non-operative arm due to excessive abduction.

Correct Answer & Explanation

. C. Potential for cerebral hypoperfusion, requiring meticulous blood pressure monitoring.

Explanation

Correct Answer: CThe case study explicitly lists 'Risk of Cerebral Hypoperfusion' as a disadvantage of the beach chair position, emphasizing that 'Careful monitoring of blood pressure is essential.' This is due to the patient's elevated head position, which can reduce cerebral blood flow if systemic blood pressure is not adequately maintained. Option A is incorrect; gravity typically assists exposure in the beach chair position, and brachial plexus injury is more related to improper head/neck positioning or arm traction, not directly 'gravity working against exposure.' Option B is incorrect; the beach chair position is not specifically associated with an increased risk of DVT in the operative arm compared to other positions. Option D is incorrect; the case states, 'Gravity Assists Exposure: The arm hangs naturally, facilitating humeral head dislocation and glenoid exposure,' which is an advantage, not a disadvantage. Option E is a general risk of improper arm positioning, but not a unique disadvantage of the beach chair position itself, and the non-operative arm is typically tucked, not excessively abducted.

Question 10

Topic: Shoulder Arthroplasty & Arthritis

A 65-year-old male presents with increased weakness in internal rotation and a positive bear-hug test 6 months after an anatomic total shoulder arthroplasty via a deltopectoral approach. What is the most likely cause of his symptoms?

. Axillary nerve injury
. Glenoid component loosening
. Subscapularis tendon failure
. Suprascapular nerve entrapment
. Coracoid impingement

Correct Answer & Explanation

. Subscapularis tendon failure

Explanation

Subscapularis failure is a known complication after anatomic TSA performed via a deltopectoral approach. It typically presents with increased external rotation, weakness in internal rotation, and positive lift-off or bear-hug tests.

Question 11

Topic: Shoulder Arthroplasty & Arthritis

The design of a Grammont-style reverse total shoulder arthroplasty alters shoulder biomechanics to compensate for rotator cuff deficiency by:

. Lateralizing and superiorly displacing the center of rotation
. Medializing and distalizing the center of rotation
. Medializing and superiorly displacing the center of rotation
. Lateralizing and distalizing the center of rotation
. Maintaining the anatomic center of rotation

Correct Answer & Explanation

. Medializing and distalizing the center of rotation

Explanation

A Grammont-style RTSA medializes and distalizes the center of rotation. This increases the deltoid lever arm and resting tension, allowing it to initiate and maintain abduction without a functioning rotator cuff.

Question 12

Topic: Shoulder Arthroplasty & Arthritis

When utilizing a reverse total shoulder arthroplasty for an acute 4-part proximal humerus fracture in an elderly patient, healing of the greater tuberosity is associated with which of the following clinical outcomes?

. Improved forward elevation but worse internal rotation
. Improved external rotation and patient satisfaction
. Increased risk of scapular notching
. Higher rate of glenoid baseplate loosening
. No significant difference in functional outcomes

Correct Answer & Explanation

. Improved external rotation and patient satisfaction

Explanation

In RTSA for proximal humerus fractures, anatomic healing of the greater tuberosity to the shaft is highly correlated with improved postoperative external rotation and superior overall patient-reported outcomes.

Question 13

Topic: Shoulder Arthroplasty & Arthritis

During a reverse total shoulder arthroplasty, the surgeon must restore adequate tension to the deltoid. Which clinical assessment is best used intraoperatively to confirm appropriate deltoid tension?

. The conjoint tendon should be tight and rigid
. The conjoint tendon should exhibit an elastic bounce
. The acromiohumeral distance should be less than 5 mm
. The subscapularis must easily reach the lesser tuberosity without tension
. The arm should spontaneously rest in 30 degrees of abduction

Correct Answer & Explanation

. The conjoint tendon should exhibit an elastic bounce

Explanation

Intraoperative assessment of proper deltoid tension in RTSA involves checking the conjoint tendon, which should have a firm but elastic "bounce". Overtensioning leads to a rigid tendon and increases the risk of acromial stress fracture.

Question 14

Topic: Shoulder Arthroplasty & Arthritis

A 65-year-old male is undergoing a reverse total shoulder arthroplasty (RTSA) for cuff tear arthropathy. To minimize the risk of scapular notching, which of the following describes the optimal positioning of the glenoid baseplate?

. Superiorly translated with superior tilt.
. Centered on the glenoid with superior tilt.
. Inferiorly translated with neutral or slight inferior tilt.
. Flush with the anterior rim and significant superior tilt.
. Centered on the glenoid with neutral tilt.

Correct Answer & Explanation

. Inferiorly translated with neutral or slight inferior tilt.

Explanation

Scapular notching in RTSA is primarily caused by mechanical impingement of the humeral component against the inferior scapular neck. It can be minimized by placing the glenoid baseplate inferiorly (flush or slightly overhanging the inferior rim) and using neutral or slight inferior tilt.

Question 15

Topic: Shoulder Arthroplasty & Arthritis

A 64-year-old female suffers a displaced 3-part proximal humerus fracture and is treated with a reverse total shoulder arthroplasty. The surgeon uses strong sutures to repair the greater tuberosity to the proximal humerus and the implant. Successful osseous healing of the greater tuberosity is most closely associated with which clinical outcome?

. Increased postoperative active internal rotation.
. Increased postoperative active external rotation.
. Decreased risk of postoperative acromial stress fracture.
. Decreased risk of scapular notching.
. Complete restoration of supraspinatus function.

Correct Answer & Explanation

. Increased postoperative active external rotation.

Explanation

In the setting of RTSA for proximal humerus fractures, anatomic reduction and healing of the greater tuberosity strictly correlate with improved active external rotation. This is because it restores the tension and function of the attached teres minor and infraspinatus.

Question 16

Topic: Shoulder Arthroplasty & Arthritis

In reverse total shoulder arthroplasty (RTSA), biomechanical stability and function rely on altering the native center of rotation (COR). How is the COR characteristically changed compared to the native shoulder?

. Medialized and superiorized
. Medialized and inferiorized
. Lateralized and superiorized
. Lateralized and inferiorized
. Maintained in its native anatomic position

Correct Answer & Explanation

. Medialized and inferiorized

Explanation

Grammont's original design for RTSA medializes and inferiorizes the center of rotation. Medialization decreases torque on the glenoid component to prevent loosening, while inferiorization recruits more deltoid fibers and increases its moment arm to restore active elevation.

Question 17

Topic: Shoulder Arthroplasty & Arthritis

A 75-year-old male presents for his 3-year follow-up after a reverse total shoulder arthroplasty. Radiographs demonstrate inferior scapular notching extending beyond the inferior glenoid screw (Sirveaux Grade 3). Which of the following surgical techniques most effectively minimizes the risk of this complication during the index procedure?

. Superior tilt of the glenosphere
. Neutral tilt with superior placement of the baseplate
. Inferior translation of the baseplate with inferior overhang of the glenosphere
. Lateralization of the humerus using a thicker polyethylene insert
. Use of a smaller diameter glenosphere

Correct Answer & Explanation

. Inferior translation of the baseplate with inferior overhang of the glenosphere

Explanation

Scapular notching is a frequent complication of RTSA caused by mechanical impingement of the humeral component against the scapular neck. Inferior placement of the baseplate with a 2 to 4 mm inferior overhang of the glenosphere is the most effective technique to prevent it.

Question 18

Topic: Shoulder Arthroplasty & Arthritis

A 62-year-old female undergoes reverse total shoulder arthroplasty (RSA) for rotator cuff arthropathy. In the original Grammont design, what is the primary biomechanical advantage conferred by the placement and design of the glenosphere?

. It lateralizes the center of rotation to increase the tension on the remaining rotator cuff
. It medializes and distalizes the center of rotation to recruit more deltoid fibers and increase their moment arm
. It places the center of rotation exactly at the anatomical native joint line
. It primarily relies on an intact coracoacromial arch for superior stability
. It increases sheer forces at the glenoid bone-implant interface to promote osseointegration

Correct Answer & Explanation

. It medializes and distalizes the center of rotation to recruit more deltoid fibers and increase their moment arm

Explanation

The Grammont reverse shoulder arthroplasty design medializes and distalizes the center of rotation. This increases the moment arm of the deltoid, recruits more anterior and posterior deltoid fibers for elevation, and converts shear forces into compressive forces at the glenoid.

Question 19

Topic: Shoulder Arthroplasty & Arthritis

In a patient undergoing reverse total shoulder arthroplasty (rTSA) for cuff tear arthropathy, how does the prosthesis alter the biomechanics of the shoulder to restore active elevation?

. Lateralizes and superiorly translates the center of rotation
. Lateralizes and inferiorly translates the center of rotation
. Medializes and distalizes the center of rotation
. Medializes and superiorly translates the center of rotation
. Maintains the anatomic center of rotation while increasing the moment arm

Correct Answer & Explanation

. Medializes and distalizes the center of rotation

Explanation

Reverse total shoulder arthroplasty (rTSA) medializes and distalizes (inferiorly translates) the center of rotation. This effectively recruits more deltoid muscle fibers and increases the deltoid's moment arm, compensating for the absent rotator cuff.

Question 20

Topic: Shoulder Arthroplasty & Arthritis

A 65-year-old female is undergoing anatomic total shoulder arthroplasty (TSA) for primary osteoarthritis. Preoperative CT planning demonstrates a B2 glenoid. What defines a Walch B2 glenoid deformity?

. Concentric wear with central erosion
. Biconcave glenoid with asymmetric posterior wear and posterior subluxation
. Monoconcave glenoid with severe posterior wear and >15 degrees of retroversion
. Dysplastic glenoid with severe retroversion
. Superior wear secondary to massive rotator cuff tear

Correct Answer & Explanation

. Biconcave glenoid with asymmetric posterior wear and posterior subluxation

Explanation

In the Walch classification, a B2 glenoid is characterized by a biconcave surface with asymmetric posterior wear and posterior subluxation of the humeral head. A B3 glenoid is monoconcave with posterior wear, and B1 indicates posterior subluxation without significant bony deformity.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page