This practice set contains high-yield board review questions covering key concepts in 2. Trauma. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 11901
Topic: 2. Trauma
What is the most common elbow fracture in adults?
Correct Answer & Explanation
. Radial head fracture
Explanation
Radial head fractures are the most common elbow fracture in adults, accounting for approximately one-third of all elbow fractures. They typically result from a fall onto an outstretched hand, transmitting axial load through the radial head. Olecranon and distal humerus fractures are also common but less frequent than radial head fractures.
Question 11902
Topic: 2. Trauma
In the context of a terrible triad injury, which fracture component is most critical to anatomical reduction for elbow stability?
Correct Answer & Explanation
. Coronoid process fracture
Explanation
In a terrible triad injury (elbow dislocation, radial head fracture, coronoid fracture), the coronoid process fracture is considered the most critical component to anatomically reduce and fix. The coronoid is a key anterior buttress of the ulna against the trochlea and provides significant anterior stability. Inadequate fixation of the coronoid often leads to persistent instability and recurrent dislocation, even if the radial head and ligaments are addressed. While the radial head is also important for stability, the coronoid is often described as the 'gatekeeper' of stability in this injury.
Question 11903
Topic: 2. Trauma
What is the significance of the radiocapitellar view on plain radiographs for elbow trauma?
Correct Answer & Explanation
. Helps identify non-displaced radial head fractures and subtle joint effusions
Explanation
The radiocapitellar (or oblique) view is a crucial radiographic view for elbow trauma. It helps to better visualize the radial head and neck, allowing for the detection of non-displaced radial head fractures or subtle fractures that may be missed on standard AP and lateral views. It also aids in identifying subtle joint effusions (e.g., 'fat pad sign') by displacing the anterior fat pad. It does not directly visualize ligaments or the olecranon fossa as well as other views.
Question 11904
Topic: 2. Trauma
A 68-year-old female sustains a comminuted, intra-articular distal humerus fracture (AO type C3). She has significant osteopenia. What is generally considered the most appropriate surgical approach for definitive fixation in this patient?
Correct Answer & Explanation
. Total elbow arthroplasty (TEA)
Explanation
For a comminuted, intra-articular distal humerus fracture (C3 type) in an elderly patient with significant osteopenia, Total Elbow Arthroplasty (TEA) often provides superior outcomes compared to ORIF. ORIF in this setting can be challenging due to poor bone quality leading to screw cutout, high rates of nonunion, and stiffness. While ORIF via a transolecranon approach is a common method for C-type fractures, the osteopenia makes arthroplasty a more predictable option for early mobilization and functional recovery. Excision and sling is inadequate for an active individual. External fixation is typically a temporizing measure. A medial approach is not ideal for complex distal humerus fractures.
Question 11905
Topic: 2. Trauma
Regarding the 'terrible triad' injury of the elbow, which of the following statements is TRUE?
Correct Answer & Explanation
. Surgical management typically involves repair of the LCL complex, radial head replacement/fixation, and coronoid fracture fixation.
Explanation
The 'terrible triad' injury of the elbow consists of a posterior elbow dislocation, a radial head fracture, and a coronoid process fracture. Surgical management aims to restore stability and involves repair of the lateral collateral ligament (LCL) complex (specifically the LUCL), fixation or replacement of the radial head, and fixation of the coronoid fracture. Early motion is crucial post-operatively to prevent stiffness, not prolonged immobilization. The coronoid fracture can vary in size and type; it is not always a large Type III fracture.
Question 11906
Topic: 2. Trauma
Which of the following fractures is most commonly associated with ulnar nerve injury at the elbow?
Correct Answer & Explanation
. Medial epicondyle fracture
Explanation
Fractures of the medial epicondyle are most commonly associated with ulnar nerve injury, as the nerve passes directly posterior to the epicondyle in the cubital tunnel. Its proximity makes it vulnerable to contusion, stretch, or entrapment. While ulnar nerve injury can occur with distal humerus or olecranon fractures, it is a hallmark association with medial epicondyle fractures, particularly in pediatric patients where it may be entrapped in the fracture site.
Question 11907
Topic: 2. Trauma
A 12-year-old patient falls directly onto the tip of their elbow. Radiographs show a minimally displaced olecranon fracture. What is a common pitfall in diagnosing olecranon fractures in children?
Correct Answer & Explanation
. Confusing it with the normal olecranon apophysis
Explanation
In children, the olecranon apophysis appears around age 9-10 and fuses by age 14-16. This normal growth plate can be mistaken for an olecranon fracture, especially if radiographs are not compared to the contralateral elbow. A true fracture line will be more irregular and often extends into the joint. Other options are less common or specific to olecranon fractures.
Question 11908
Topic: 2. Trauma
A patient presents with persistent pain and clicking in the elbow, especially with pronation and supination, after a radial head fracture treated non-operatively. Examination reveals tenderness over the radiocapitellar joint. What is a likely cause of these symptoms?
Correct Answer & Explanation
. Chondromalacia or osteochondral defect of the radial head or capitellum
Explanation
Persistent pain and clicking after a radial head fracture, especially with pronation/supination, suggest issues with the radiocapitellar joint. This could be due to chondromalacia, osteochondral defects, or malunion of the radial head affecting articulation with the capitellum. UCL insufficiency would present as valgus instability. PIN entrapment is purely motor. Coronoid nonunion is less likely to cause clicking specific to pronation/supination. HO in the olecranon fossa would limit extension/flexion, not primarily clicking with rotation.
Question 11909
Topic: 2. Trauma
What is the typical management for a minimally displaced, stable Type I coronoid fracture?
Correct Answer & Explanation
. Sling immobilization with early protected range of motion
Explanation
Type I coronoid fractures (tip avulsion) are typically small, minimally displaced, and do not significantly compromise elbow stability on their own. They are commonly managed non-operatively with sling immobilization for comfort, followed by early protected range of motion to prevent stiffness while allowing healing. Larger, displaced coronoid fractures (Type II and III) or those associated with elbow instability (e.g., terrible triad) usually require surgical fixation.
Question 11910
Topic: 2. Trauma
What is the typical mechanism of injury for a Monteggia fracture-dislocation?
Correct Answer & Explanation
. Fall on an outstretched hand with the forearm in pronation and axial load
Explanation
A Monteggia fracture-dislocation typically results from a fall on an outstretched hand with the forearm in pronation and an axial load, causing the ulna to fracture and the radial head to dislocate, usually anteriorly. The Bado classification describes four types based on the direction of radial head dislocation. Direct blows, supination falls, repetitive valgus stress, and hyperextension injuries are associated with other specific elbow pathologies.
Question 11911
Topic: 2. Trauma
What is the most effective initial management for acute simple elbow dislocation (without associated fractures)?
Correct Answer & Explanation
. Closed reduction, assessment of stability, and early protected range of motion
Explanation
The most effective initial management for acute simple elbow dislocations is prompt closed reduction. After reduction, stability should be assessed (often under fluoroscopy). If stable, early protected range of motion is crucial to prevent stiffness, typically within a functional brace. Prolonged immobilization (e.g., 6 weeks) is detrimental due to the high risk of severe stiffness and heterotopic ossification. Surgical exploration or external fixation is reserved for irreducible dislocations or those with associated unstable fractures.
Question 11912
Topic: 2. Trauma
What is the most common cause of recurrent elbow instability after surgical repair of a terrible triad injury?
Correct Answer & Explanation
. Inadequate fixation or replacement of the radial head
Explanation
The most common cause of recurrent instability following surgical management of a terrible triad injury is inadequate fixation or replacement of the radial head. The radial head plays a crucial role as a secondary stabilizer, especially against valgus stress. If it is not adequately addressed (either by stable fixation or appropriate replacement), valgus instability can persist or recur, leading to failure of the entire construct. While MCL repair is important, the radial head's contribution to stability is often underestimated. Coronoid nonunion is also possible but often secondary to overall instability. Excessive early mobilization can contribute but if the fix is strong, it's less likely the primary cause.
Question 11913
Topic: 2. Trauma
An 84-year-old lady presents with a proximal humerus fracture. Her X-rays reveal a surgical neck fracture with 1.2cm displacement and 50 degrees of angulation. According to the Neer classification, how would you classify this fracture?
Correct Answer & Explanation
. Neer 2-part surgical neck fracture
Explanation
The Neer classification system defines 'parts' based on significant displacement (>1cm or >45 degrees angulation) of the four major segments: humeral head (articular segment), greater tuberosity, lesser tuberosity, and humeral shaft. In this scenario, the surgical neck fracture separates the humeral head from the shaft. Since there is 1.2cm displacement and 50 degrees angulation, these two segments (head and shaft) are considered significantly displaced relative to each other. With only these two main segments displaced, it is classified as a 2-part surgical neck fracture. A 3-part would involve one tuberosity in addition to the head-shaft displacement, and a 4-part would involve both tuberosities plus the head-shaft displacement. Valgus-impacted fractures are a specific stable variant, usually 1- or 2-part, where the head is impacted into the shaft in valgus.
Question 11914
Topic: 2. Trauma
An 84-year-old female sustains a proximal humerus fracture. Her X-ray shows a fracture through the surgical neck and a fracture of the greater tuberosity, with the articular segment displaced in a valgus-impacted pattern. The lesser tuberosity is intact. How would this fracture be classified using the Neer system?
Correct Answer & Explanation
. Neer 3-part valgus-impacted fracture
Explanation
This describes a Neer 3-part fracture (humeral head, greater tuberosity, and shaft, with the surgical neck fracture separating the head from the shaft, and the greater tuberosity also fractured). The 'valgus-impacted' descriptor indicates a stable, often comminuted, but well-aligned fracture pattern where the head is driven into the shaft in valgus. It modifies the 3-part classification but doesn't change the number of displaced parts. The four parts are humeral head, greater tuberosity, lesser tuberosity, and shaft. Here, the head, greater tuberosity, and shaft are involved, making it a 3-part.
Question 11915
Topic: 2. Trauma
An 84-year-old woman falls and presents with a painful, deformed shoulder. Her X-rays show a comminuted proximal humerus fracture with the humeral head clearly dislocated anteriorly from the glenoid fossa. What is the most appropriate description of this injury?
Correct Answer & Explanation
. Fracture-dislocation of the shoulder
Explanation
The presence of both a fracture and a dislocation warrants the comprehensive term 'fracture-dislocation.' While it may also be a Neer 4-part fracture, 'fracture-dislocation' specifically captures both components of the injury. Anterior glenohumeral dislocation is only part of the injury. Luxatio erecta is a rare inferior dislocation. Pathologic fracture suggests an underlying bone lesion, which is not stated.
Question 11916
Topic: 2. Trauma
An 84-year-old female presents with persistent shoulder pain months after a proximal humerus fracture. Her X-ray shows increased density of the humeral head, flattening of the articular surface, and subchondral collapse ('crescent sign'). These findings are most suggestive of:
Correct Answer & Explanation
. Avascular necrosis of the humeral head
Explanation
The radiographic features described (increased density/sclerosis, flattening, subchondral collapse, 'crescent sign') are pathognomonic for avascular necrosis (AVN) of the humeral head, which is a common complication following displaced proximal humerus fractures, especially 3- and 4-part injuries due to disruption of the blood supply. Rotator cuff arthropathy would show superior migration. GHOA would show joint space narrowing and osteophytes but not necessarily increased density and collapse initially. Septic arthritis causes rapid joint destruction and effusion. CPPD shows chondrocalcinosis and often OA.
Question 11917
Topic: 2. Trauma
A fracture of the anatomical neck of the humerus is distinct from a surgical neck fracture radiographically by its location. The anatomical neck lies:
Correct Answer & Explanation
. Proximal to the tuberosities, at the articular cartilage margin
Explanation
The anatomical neck is the groove separating the humeral head (articular surface) from the tuberosities. Fractures here are intra-articular and have a higher risk of avascular necrosis due to disruption of the blood supply entering through the metaphyseal bone. The surgical neck is distal to the tuberosities, a common site for extra-articular fractures.
Question 11918
Topic: 2. Trauma
You suspect a metastatic lesion in the proximal humerus of an 84-year-old woman. What radiographic characteristic, beyond a lytic or blastic appearance, would specifically raise concern for pathological fracture risk?
Correct Answer & Explanation
. Cortical breach or thinning greater than 50% of the bone width
Explanation
A cortical breach or thinning of the cortex greater than 50% of the bone's width significantly compromises structural integrity and indicates a high risk of pathological fracture. This is a critical radiographic sign to look for in patients with suspected metastatic bone disease. Subchondral sclerosis and osteophytes are signs of degenerative joint disease. Maintained joint space is not directly related to fracture risk of a shaft lesion. Well-defined margins are less indicative of fracture risk than cortical involvement.
Question 11919
Topic: 2. Trauma
When reviewing a shoulder X-ray, you notice a distinct, thin, radiopaque line projected across the humeral head, not conforming to anatomical structures. What is the most likely explanation for this finding?
Correct Answer & Explanation
. A radiographic artifact (e.g., clothing seam)
Explanation
A thin, radiopaque line that does not conform to known anatomical structures or fracture patterns, especially if it appears too sharp or linear, is highly suspicious for a radiographic artifact, such as a clothing seam, zipper, or hair braid. Stress fractures, pathological fractures, and AVN (crescent sign) have specific radiographic appearances related to bone pathology. Vascular calcifications typically follow vessel paths.
Question 11920
Topic: 2. Trauma
In the Neer classification of proximal humerus fractures, what are the criteria for considering a fracture fragment 'displaced' and counting it as an additional 'part'?
Correct Answer & Explanation
. Displacement greater than 1cm or angulation greater than 45 degrees
Explanation
According to the Neer classification, a fracture fragment is considered 'displaced' (and thus counts as an additional 'part' beyond the initial two segments of head and shaft) if there is greater than 1cm of displacement or greater than 45 degrees of angulation. This threshold helps distinguish significantly displaced fractures requiring more aggressive treatment from minimally displaced ones.
Test Yourself
Switch to an interactive, timed exam simulation to truly master this topic.