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Elbow & Forearm MCQs

Practice Set 7 of 57

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

Question 121

Topic: Elbow & Forearm

A 7-year-old boy presents with a missed Bado Type I Monteggia fracture-dislocation that occurred 6 months ago. The radial head remains anteriorly dislocated, and the ulnar fracture is malunited. What is the most appropriate and successful surgical management at this stage?

. Radial head excision to improve forearm rotation
. In situ annular ligament reconstruction without ulnar intervention
. Ulnar lengthening/angulation osteotomy with open reduction of the radial head
. Radial shortening osteotomy to decompress the radiocapitellar joint
. Observation and physical therapy until skeletal maturity

Correct Answer & Explanation

. Ulnar lengthening/angulation osteotomy with open reduction of the radial head

Explanation

The treatment of a chronic, missed pediatric Monteggia fracture requires an ulnar osteotomy to correct the angulation and restore length. This addresses the primary bone deformity, allowing for reduction of the radial head, often supplemented by annular ligament reconstruction.

Question 122

Topic: Elbow & Forearm

When performing surgical reconstruction for a terrible triad injury of the elbow, what is the generally recommended, step-wise sequence to restore joint stability?

. Lateral collateral ligament repair, radial head fixation, coronoid fixation
. Medial collateral ligament repair, coronoid fixation, radial head replacement
. Coronoid fixation, radial head fixation or replacement, lateral collateral ligament repair
. Radial head fixation, lateral collateral ligament repair, coronoid fixation
. Coronoid fixation, medial collateral ligament repair, radial head replacement

Correct Answer & Explanation

. Coronoid fixation, radial head fixation or replacement, lateral collateral ligament repair

Explanation

The standard surgical algorithm for a terrible triad injury follows a 'deep to superficial' or 'inside-out' approach. Reconstruction proceeds by first addressing the coronoid, then fixing or replacing the radial head, and finally repairing the lateral collateral ligament (LCL) complex.

Question 123

Topic: Elbow & Forearm
A 58-year-old active construction worker presents with a Mason-Johnston Type III radial head fracture after a fall. Radiographs show severe comminution with four distinct fragments involving approximately 60% of the articular surface. There is no associated elbow dislocation. He desires to return to full work capacity. Which of the following is the most appropriate surgical management to restore function and stability?
. Open reduction and internal fixation (ORIF) with headless screws
. Radial head excision
. Radial head replacement
. Non-operative management with early range of motion
. Primary elbow arthrodesis

Correct Answer & Explanation

. Radial head replacement

Explanation

For a highly comminuted (Mason-Johnston Type III or IV) radial head fracture, especially in an active patient who desires a full return to function, radial head replacement is often the preferred surgical option. ORIF would be technically challenging or impossible with four fragments involving 60% of the articular surface, and stable fixation is unlikely. Radial head excision, while an option for low-demand patients, carries a significant risk of proximal radial migration and DRUJ instability, which would be detrimental to an active construction worker. Non-operative management is inappropriate for such a severely comminuted and displaced fracture. Primary elbow arthrodesis is a salvage procedure for end-stage arthritis or instability, not an acute fracture.

Question 124

Topic: Elbow & Forearm

During open reduction and internal fixation (ORIF) of a Mason-Johnston Type II radial head fracture, the surgeon plans to use headless compression screws. To minimize the risk of hardware impingement against the capitellum or ulna during forearm rotation, where is the ideal 'safe zone' for screw placement on the radial head?

. 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 the lesser sigmoid notch of the ulna throughout the full 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 the lesser sigmoid notch of the ulna throughout the full arc of forearm rotation

Explanation

Correct Answer: CThe 'safe zone' for hardware placement in the radial head is a critical concept in ORIF to prevent impingement. This zone refers to the portion of the radial head that does not articulate with the capitellum of the humerus or the lesser sigmoid notch of the ulna through a full range of forearm pronation and supination. It is typically described as a 110-degree arc on the radial head, often corresponding to the posterolateral quadrant when the forearm is in neutral rotation. Placing hardware outside this zone can lead to pain, crepitus, and a mechanical block to motion, necessitating hardware removal. The other options describe articulating surfaces or specific quadrants that are not universally 'safe' throughout the entire range of motion.

Question 125

Topic: Elbow & Forearm

A 42-year-old female presents to the emergency department after a high-energy fall, sustaining a posterior elbow dislocation, a comminuted radial head fracture (Mason-Johnston Type IV), and a coronoid process fracture. After successful closed reduction of the elbow, radiographs are obtained, as shown below. What is the most critical ligamentous injury associated with this 'terrible triad' pattern that must be assessed and potentially addressed to ensure elbow stability?

. Medial collateral ligament (MCL)
. Annular ligament
. Lateral ulnar collateral ligament (LUCL)
. Oblique cord
. Radiocapitellar ligament

Correct Answer & Explanation

. Lateral ulnar collateral ligament (LUCL)

Explanation

Correct Answer: CThe 'terrible triad' of the elbow consists of a posterior elbow dislocation, a radial head fracture, and a coronoid process fracture. This injury pattern is characterized by significant instability. The most consistently injured and critical ligament for posterolateral rotatory stability of the elbow in this context is the lateral ulnar collateral ligament (LUCL). Injury to the LUCL, often avulsed from its humeral origin, allows for posterolateral subluxation or dislocation of the ulna relative to the humerus. While the MCL can also be injured, and the annular ligament is disrupted with the radial head fracture, the LUCL is the key structure whose integrity dictates posterolateral rotatory stability and often requires repair or reconstruction in conjunction with radial head replacement and coronoid fixation.

Question 126

Topic: Elbow & Forearm
A 72-year-old sedentary patient presents with a Mason-Johnston Type III radial head fracture with severe comminution. She has significant comorbidities and is not a candidate for a lengthy or complex surgical procedure. She desires pain relief and improved elbow motion for basic activities of daily living. 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 (due to comminution or bone quality) or do not desire more extensive surgery like radial head replacement (due to comorbidities or complexity), 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. ORIF is often not feasible due to comminution. Replacement is a good option but more involved surgery. Arthrodesis is a salvage procedure. Long arm casting would likely lead to severe stiffness in this age group and is generally avoided for radial head fractures.

Question 127

Topic: Elbow & Forearm

A 45-year-old male undergoes open reduction and internal fixation (ORIF) of a Mason-Johnston Type II radial head fracture. Two weeks post-operatively, he complains of persistent elbow pain, stiffness, and crepitus, particularly with forearm rotation, despite diligent physical therapy. Radiographs, shown below, confirm stable fixation with no obvious loosening. What is the most common cause of *early* post-operative stiffness and pain in this scenario?

. Infection
. Nerve injury
. Hardware prominence and impingement
. Aseptic loosening of the implant
. Non-union of the fracture

Correct Answer & Explanation

. Hardware prominence and impingement

Explanation

Correct Answer: CEarly post-operative stiffness, pain, and crepitus following radial head fracture fixation are very commonly caused by hardware prominence and impingement. If screws or plates are not properly countersunk or are placed outside the 'safe zone' (the non-articulating portion of the radial head), they can impinge on the capitellum or the lesser sigmoid notch of the ulna during elbow flexion-extension or forearm rotation. This mechanical impingement causes pain and restricts range of motion. While infection, nerve injury, and non-union are possible complications, hardware impingement is a leading cause of early stiffness directly related to the fixation itself. Aseptic loosening is typically a later complication.

Question 128

Topic: Elbow & Forearm

A 32-year-old female presents with a Mason-Johnston Type I radial head fracture after a low-energy fall. Radiographs, as shown below, reveal a non-displaced crack in the radial head with no articular step-off. On examination, she has mild pain but full, pain-free forearm pronation and supination. What is the most appropriate initial management strategy?

. 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

Correct Answer: CMason-Johnston Type I radial head fractures are characterized by a non-displaced crack or minimal displacement (less than 2mm) without a mechanical block to forearm rotation. For these injuries, non-operative management is the standard of care. This typically involves a brief period of immobilization (e.g., a few days to 1 week in a sling for comfort) followed by early active range of motion exercises. Prolonged immobilization, such as a long arm cast, should be avoided as it significantly increases the risk of elbow stiffness, a common and debilitating complication. Surgical interventions like ORIF, radial head replacement, or excision are not indicated for Type I fractures.

Question 129

Topic: Elbow & Forearm

A 45-year-old male sustains a 'terrible triad' injury of the elbow following a fall. According to standard surgical protocols, what is the most appropriate sequence of repair after exposing the joint?

. Repair the lateral collateral ligament (LCL), fix the radial head, then fix the coronoid.
. Fix the coronoid, fix or replace the radial head, then repair the LCL complex.
. Fix the radial head, repair the medial collateral ligament (MCL), then fix the coronoid.
. Repair the MCL, fix the coronoid, then fix the radial head.
. Fix the coronoid, repair the MCL, then fix or replace the radial head.

Correct Answer & Explanation

. Fix the coronoid, fix or replace the radial head, then repair the LCL complex.

Explanation

The standard surgical sequence for a terrible triad injury involves addressing the structures from deep to superficial: fixing the coronoid, fixing or replacing the radial head, and finally repairing the lateral collateral ligament (LCL). If instability persists after these steps, the MCL or a hinged external fixator may be considered.

Question 130

Topic: Elbow & Forearm

A 45-year-old male sustains a 'terrible triad' injury of the elbow (dislocation, coronoid fracture, and radial head fracture). During operative management, what is the most widely accepted standard surgical sequence for reconstruction?

. Repair the lateral collateral ligament (LCL), fix the radial head, then fix the coronoid.
. Fix or replace the radial head, repair the medial collateral ligament (MCL), then fix the coronoid.
. Fix the coronoid, fix or replace the radial head, then repair the lateral collateral ligament (LCL).
. Repair the medial collateral ligament (MCL), fix the coronoid, then fix or replace the radial head.
. Fix the coronoid, repair the lateral collateral ligament (LCL), then replace the radial head.

Correct Answer & Explanation

. Fix the coronoid, fix or replace the radial head, then repair the lateral collateral ligament (LCL).

Explanation

The standard surgical algorithm for a terrible triad injury works from deep to superficial and medial to lateral: fix the coronoid first, address the radial head (fixation or arthroplasty), and finally repair the LCL complex to restore posterolateral stability. The MCL is rarely repaired unless instability persists after addressing the other three components.

Question 131

Topic: Elbow & Forearm
A 32-year-old female sustains a coronal shear fracture of the distal humerus that involves the capitellum and the majority of the trochlea. According to the Bryan and Morrey classification with McKee modification, what type is this fracture, and what is the optimal surgical approach?
. Type I (Hahn-Steinthal) / Lateral approach
. Type II (Kocher-Lorenz) / Medial approach
. Type III (Broberg-Morrey) / Posterior approach
. Type IV (McKee) / Extensile lateral or universal posterior approach
. Type V (Jupiter) / Anterior approach

Correct Answer & Explanation

. Type IV (McKee) / Extensile lateral or universal posterior approach

Explanation

The McKee modification (Type IV) describes a coronal shear fracture extending medially to involve the capitellum and most of the trochlea. To adequately visualize and fix both the capitellum and trochlear fragments, an extensile lateral approach or a posterior approach with an olecranon osteotomy is required.

Question 132

Topic: Elbow & Forearm
A 35-year-old male sustains a proximal ulna shaft fracture with an associated anterior dislocation of the radial head. According to the Bado classification, what type of Monteggia fracture is this, and what is the standard operative management?
. Bado Type I / Non-operative management in a long arm cast
. Bado Type I / ORIF of the ulna with closed reduction of the radial head
. Bado Type II / ORIF of both the ulna and radial head
. Bado Type III / Closed reduction of both bones
. Bado Type IV / External fixation of the ulna

Correct Answer & Explanation

. Bado Type I / ORIF of the ulna with closed reduction of the radial head

Explanation

Bado Type I describes a proximal ulna fracture with anterior dislocation of the radial head, the most common type. In adults, the standard of care is anatomic ORIF of the ulna, which typically results in spontaneous, stable closed reduction of the radial head.

Question 133

Topic: Elbow & Forearm

A 45-year-old female presents with an elbow injury after a fall. Radiographs and CT show a coronal shear fracture of the capitellum extending into the lateral ridge of the trochlea, with posterior comminution. According to the Dubberley classification, what is the best surgical approach and fixation strategy?

. Closed reduction and casting
. Lateral extensile approach with anterior to posterior headless screws
. Extensile lateral approach with posterior plating and anterior screws
. Medial approach with isolated trochlear screws
. Fragment excision and radial head replacement

Correct Answer & Explanation

. Extensile lateral approach with posterior plating and anterior screws

Explanation

This is a Dubberley Type 3B fracture (involving capitellum and trochlea with posterior comminution). Posterior comminution dictates the need for posterior buttress plating to prevent displacement, typically requiring an extensile lateral or posterior approach.

Question 134

Topic: Elbow & Forearm

In the surgical management of a 'terrible triad' injury of the elbow (elbow dislocation, radial head fracture, coronoid fracture), what is the generally accepted and most biomechanically sound sequence of reconstruction?

. LCL repair, radial head fixation, coronoid fixation
. Radial head fixation, LCL repair, coronoid fixation
. Coronoid fixation, radial head fixation/replacement, LCL repair
. Coronoid fixation, LCL repair, radial head fixation
. LCL repair, coronoid fixation, radial head fixation

Correct Answer & Explanation

. Coronoid fixation, radial head fixation/replacement, LCL repair

Explanation

The standard deep-to-superficial approach to the terrible triad involves fixing structures from inside out: first the coronoid, then the radial head (fixation or arthroplasty), and finally repairing the lateral collateral ligament (LCL) complex.

Question 135

Topic: Elbow & Forearm

A 35-year-old male undergoes a two-incision repair of a complete distal biceps tendon rupture. Six months postoperatively, he complains of a severe limitation in forearm rotation. Radiographs demonstrate a radioulnar synostosis. Which specific intraoperative maneuver during the surgical approach is most strongly associated with this complication?

. Extensive dissection through the interosseous membrane
. Subperiosteal dissection and exposure of the proximal ulna during the posterior approach
. Vigorous retraction of the lateral antebrachial cutaneous nerve
. Placement of an endobutton through the posterior radial cortex
. Use of a single anterior incision instead of two incisions

Correct Answer & Explanation

. Subperiosteal dissection and exposure of the proximal ulna during the posterior approach

Explanation

Radioulnar synostosis is a known complication of the two-incision (Boyd) approach for distal biceps repair. It is most commonly caused by subperiosteal elevation of the supinator and stripping of the proximal ulna, which triggers heterotopic ossification bridging the radius and ulna.

Question 136

Topic: Elbow & Forearm

A 35-year-old male sustains a mid-diaphyseal both bones forearm fracture. During surgical planning, the surgeon considers the role of the interosseous membrane. Which statement best describes its primary biomechanical function in the context of forearm stability?

. It serves as the primary attachment site for the pronator quadratus muscle.
. It acts as a passive ligamentous stabilizer, transferring axial load from the radius to the ulna.
. It provides a vascular conduit for the nutrient arteries of the radius and ulna.
. It facilitates smooth gliding between the radius and ulna during pronation and supination.
. It prevents distal migration of the radial head.

Correct Answer & Explanation

. It acts as a passive ligamentous stabilizer, transferring axial load from the radius to the ulna.

Explanation

Correct Answer: BThe interosseous membrane (IOM) acts as a crucial passive ligamentous stabilizer (Option B) in the forearm. Its primary biomechanical function is to transfer axial load from the radius to the ulna, particularly during gripping and weight-bearing activities through the wrist. It also provides stability against longitudinal and rotational forces, maintaining the relative positions of the radius and ulna. Disruption of the IOM (e.g., in Essex-Lopresti injuries) leads to severe instability of the forearm and wrist.Incorrect Options:A. It serves as the primary attachment site for the pronator quadratus muscle:While some muscles (e.g., FPL, FDP) originate from the IOM, the pronator quadratus primarily attaches to the distal metaphysis of the radius and ulna. The IOM's primary role is not muscle attachment.C. It provides a vascular conduit for the nutrient arteries of the radius and ulna:The nutrient arteries enter the bone directly and are not primarily housed within the IOM as a conduit. The anterior and posterior interosseous arteries run along the membrane, but the membrane itself is not the primary vascular conduit for the bones.D. It facilitates smooth gliding between the radius and ulna during pronation and supination:The IOM is a fibrous structure that limits motion rather than facilitating smooth gliding. The articular surfaces of the radial head and distal radioulnar joint, along with the capsule, facilitate gliding.E. It prevents distal migration of the radial head:The IOM helps maintain the longitudinal stability of the forearm, which indirectly supports the radial head. However, the annular ligament and the integrity of the proximal radioulnar joint are the primary structures preventing distal migration of the radial head.

Question 137

Topic: Elbow & Forearm

An Essex-Lopresti lesion involves a radial head fracture with concomitant injury to the interosseous membrane and DRUJ. To prevent severe longitudinal radioulnar dissociation, which of the following treatments is strictly contraindicated?

. Radial head ORIF
. Radial head arthroplasty
. Radial head excision
. Ulnar shortening osteotomy
. Interosseous membrane reconstruction

Correct Answer & Explanation

. Radial head excision

Explanation

Radial head excision is contraindicated in Essex-Lopresti injuries. Removal of the radial head eliminates the primary proximal restraint to longitudinal migration, leading to catastrophic proximal migration of the radius, positive ulnar variance, and severe wrist pain.

Question 138

Topic: Elbow & Forearm

What defines the primary biomechanical axis of rotation for the forearm during pronation and supination?

. A line from the center of the radial head to the center of the distal articular surface of the radius
. A line from the lateral epicondyle to the tip of the ulnar styloid
. A line from the center of the radial head to the fovea of the distal ulna
. A line from the coronoid process to the Lister tubercle
. A line from the capitellum to the volar radioulnar ligament

Correct Answer & Explanation

. A line from the center of the radial head to the fovea of the distal ulna

Explanation

The functional longitudinal axis of forearm rotation passes obliquely from the center of the radial head proximally to the fovea at the base of the ulnar styloid distally.

Question 139

Topic: Elbow & Forearm

A 45-year-old female presents with a highly comminuted radial head fracture, wrist pain, and proximal migration of the radius on radiographs. An Essex-Lopresti injury is suspected. Which treatment strategy is strongly contraindicated in this patient?

. Radial head excision alone
. Radial head arthroplasty
. Open reduction and internal fixation of the radial head
. Pinning of the distal radioulnar joint
. Immobilization in supination following radial head replacement

Correct Answer & Explanation

. Radial head excision alone

Explanation

In an Essex-Lopresti injury (interosseous membrane tear with DRUJ disruption), radial head excision removes the proximal block to radius migration. This leads to severe ulnar positive variance and chronic wrist pain.

Question 140

Topic: Elbow & Forearm
A 40-year-old male is evaluated for chronic wrist pain and weakness following a highly displaced radial head fracture treated with excision. Radiographs reveal 5 mm of proximal radial migration. What is the most appropriate reconstructive option to restore longitudinal stability?
. Radial head arthroplasty
. Ulnar shortening osteotomy
. Radial head arthroplasty with ulnar shortening osteotomy
. Distal radioulnar joint arthrodesis (Sauvé-Kapandji)
. Creation of a one-bone forearm

Correct Answer & Explanation

. Radial head arthroplasty with ulnar shortening osteotomy

Explanation

In a chronic Essex-Lopresti lesion with established proximal radial migration, radial head arthroplasty alone is insufficient due to soft tissue contracture. A combined procedure, typically radial head arthroplasty with an ulnar shortening osteotomy, is required to level the DRUJ and restore stability.

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