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2. Trauma MCQs

Practice Set 599 of 640

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 11961

Topic: 2. Trauma

A 55-year-old male with end-stage renal disease on hemodialysis presents with a sudden inability to actively extend his elbow after a fall onto a flexed arm. A lateral radiograph of the elbow reveals a small osseous avulsion fragment situated proximal to the olecranon fossa. What is this radiographic finding commonly called, and what does it signify?

. Fat pad sign; occult radial head fracture
. Fleck sign; acute triceps tendon rupture
. Terry Thomas sign; scapholunate dissociation
. Teardrop sign; intra-articular effusion
. Gull-wing sign; erosive osteoarthritis

Correct Answer & Explanation

. Fleck sign; acute triceps tendon rupture

Explanation

The 'fleck sign' on a lateral elbow radiograph refers to a small avulsion fracture of the olecranon tip. In a patient with loss of active elbow extension, this is highly suggestive of a triceps tendon rupture. Triceps ruptures are rare but are strongly associated with systemic risk factors such as chronic kidney disease, hyperparathyroidism, and anabolic steroid or fluoroquinolone use.

Question 11962

Topic: 2. Trauma
A 26-year-old male cyclist falls directly onto his right shoulder. Radiographs demonstrate a fracture of the distal third of the clavicle. The fracture line is located just medial to the coracoclavicular (CC) ligaments, which remain attached entirely to the distal fracture fragment. The proximal fragment is significantly displaced superiorly. According to the Neer classification, what type of distal clavicle fracture is this, and what is its clinical significance?
. Type I; high rate of nonunion
. Type I; typically heals well with a sling
. Type II; high rate of nonunion due to deforming forces
. Type III; high risk of late acromioclavicular arthritis
. Type IV; common in children due to periosteal sleeve avulsion

Correct Answer & Explanation

. Type II; high rate of nonunion due to deforming forces

Explanation

According to the Neer classification for distal clavicle fractures, a Type II fracture occurs when the fracture is at the level of the CC ligaments. The ligaments are either torn (IIA) or intact but attached to the distal fragment (IIB), leaving the proximal fragment devoid of CC ligamentous restraint. The trapezius pulls the proximal fragment superiorly, while the weight of the arm pulls the distal fragment inferiorly. This loss of stability leads to a high rate of nonunion (up to 30-45%) if treated nonoperatively, frequently necessitating surgical fixation.

Question 11963

Topic: 2. Trauma

A 40-year-old carpenter presents with a painful, cold, and pale right index and middle finger. Allen's test indicates ulnar artery occlusion. Angiography reveals a corkscrew appearance and occlusion of the ulnar artery. In Hypothenar Hammer Syndrome, the ulnar artery is most commonly traumatized against which bony prominence?

. Pisiform
. Hook of the hamate
. Trapezium ridge
. Lister's tubercle
. Styloid process of the ulna

Correct Answer & Explanation

. Hook of the hamate

Explanation

Hypothenar Hammer Syndrome results from repetitive blunt trauma to the hypothenar eminence (e.g., using the palm as a hammer). The ulnar artery is injured as it passes superficially over the hook of the hamate, leading to thrombosis or aneurysm formation and subsequent distal embolization.

Question 11964

Topic: 2. Trauma

In a rheumatoid patient, the development of skin erythema, warmth, and intense pain disproportionate to visible deformity or trauma in the foot should raise suspicion for:

. Acute gouty arthritis
. Cellulitis
. Complex Regional Pain Syndrome (CRPS)
. An acute flare of MTP synovitis
. A stress fracture

Correct Answer & Explanation

. Complex Regional Pain Syndrome (CRPS)

Explanation

While acute MTP synovitis can cause erythema and warmth, and cellulitis is always a concern, Complex Regional Pain Syndrome (CRPS) should be considered in rheumatoid patients with disproportionate pain, skin changes (erythema, warmth, edema, trophic changes), and autonomic dysfunction, especially following trauma or surgery, but sometimes spontaneously. It often presents with symptoms that are out of proportion to the objective findings or expected course of a typical inflammatory flare. Gout is a differential but less likely if it's not the primary diagnosis. Stress fracture pain is usually more localized.

Question 11965

Topic: 2. Trauma
Which of the following describes the most common classification system used to stage infected total knee arthroplasties based on onset time?
. Cierny-Mader Classification.
. Coventry Classification.
. Gustilo-Anderson Classification.
. Frick Classification.
. Masri Classification.

Correct Answer & Explanation

. Coventry Classification.

Explanation

The Coventry Classification (also known as the classic classification system) categorizes PJI based on the time of onset: Type I (acute postoperative, within 3 months), Type II (delayed/early chronic, 3-24 months), and Type III (late/chronic hematogenous, >24 months). This helps guide treatment decisions. Cierny-Mader is for osteomyelitis, Gustilo-Anderson for open fractures. Frick and Masri are not standard PJI classifications.

Question 11966

Topic: 2. Trauma

Which of the following is a common long-term complication associated with chronic lateral ankle instability, even after successful surgical stabilization?

. Acute compartment syndrome
. Deep vein thrombosis
. Post-traumatic ankle osteoarthritis
. Infection of the ankle joint
. Heterotopic ossification

Correct Answer & Explanation

. Post-traumatic ankle osteoarthritis

Explanation

Post-traumatic ankle osteoarthritis is a common long-term complication of chronic lateral ankle instability, even after surgical stabilization. The recurrent instability, altered joint mechanics, and repetitive microtrauma can lead to cartilage damage and progressive degenerative changes in the ankle joint. While other complications can occur, osteoarthritis is a specific chronic sequela related to the pathology itself. Compartment syndrome and DVT are acute complications, infection is a surgical complication, and heterotopic ossification is less common in the ankle compared to other joints like the hip or elbow after trauma.

Question 11967

Topic: Lower Extremity Trauma

Regarding rotational alignment in TKA, which anatomical landmark is considered the most reliable guide for external rotation of the femoral component?

. Whiteside's line (Perpendicular to the transepicondylar axis)
. Posterior condylar line (Parallel to the posterior femoral condyles)
. Trans-epicondylar axis (TEA)
. Anterior-posterior axis (AP axis)
. Femoral shaft axis

Correct Answer & Explanation

. Trans-epicondylar axis (TEA)

Explanation

The Transepicondylar Axis (TEA) is considered the most reliable and anatomically consistent reference for femoral component rotation, representing the functional flexion axis of the knee. The femoral component is typically aligned parallel or slightly externally rotated (3-5 degrees) to the TEA. Whiteside's line (or the anteroposterior axis) is perpendicular to the TEA. The posterior condylar line can be unreliable in osteoarthritic knees due to posterior condylar wear. The femoral shaft axis guides coronal alignment, not rotation.

Question 11968

Topic: 2. Trauma

What is the consequence of placing the femoral component in excessive external rotation (beyond 5-7 degrees relative to TEA)?

. Increased medial patellofemoral pressure
. Tightening of the lateral flexion gap
. Medial collateral ligament laxity in flexion
. Increased anterior knee pain due to patellar baja
. Increased risk of posterior femoral condyle fracture

Correct Answer & Explanation

. Medial collateral ligament laxity in flexion

Explanation

Placing the femoral component in excessive external rotation can lead to a relatively loose medial flexion gap, potentially causing medial collateral ligament (MCL) laxity in flexion and varus instability. It effectively 'opens up' the medial side. Increased medial patellofemoral pressure is more typical of internal rotation. Tightening of the lateral flexion gap is also incorrect. Patellar baja is related to patellar component positioning. Condyle fracture is less likely than instability.

Question 11969

Topic: Lower Extremity Trauma

In a TKA for a severe varus deformity, what is a common pitfall in tibial component placement regarding coronal alignment, if not properly addressed?

. Placing the tibial component in excessive valgus
. Placing the tibial component in varus, parallel to the resected bone surface
. Placing the tibial component with excessive anterior slope
. Over-resection of the lateral tibial plateau
. Under-resection of the medial tibial plateau

Correct Answer & Explanation

. Placing the tibial component in varus, parallel to the resected bone surface

Explanation

In a severe varus knee, the medial tibial plateau is typically worn and depressed. If the surgeon simply resects bone parallel to this worn surface, the tibial component will inadvertently be placed in varus, which is a common cause of early loosening. The goal is to create a neutral or slight valgus (0-3 degrees) alignment relative to the mechanical axis of the tibia, which requires resecting more bone from the intact (lateral) side relative to the worn (medial) side, or using proper alignment guides. Over-resection of the lateral tibial plateau could lead to valgus malalignment, but the most common pitfall whennot properly addressedis varus.

Question 11970

Topic: Lower Extremity Trauma

Which rotational guide for the femoral component is considered 'anatomic' and least affected by femoral condylar wear?

. Posterior Condylar Axis
. Whiteside's Line (AP axis)
. Trans-epicondylar Axis (TEA)
. Anterior Condylar Axis
. Femoral Shaft Axis

Correct Answer & Explanation

. Trans-epicondylar Axis (TEA)

Explanation

The Transepicondylar Axis (TEA), connecting the most prominent points of the medial and lateral epicondyles, is considered the most anatomically consistent and reliable reference for femoral component rotation. It represents the functional flexion-extension axis of the knee and is least affected by femoral condylar wear compared to the posterior condylar axis. Whiteside's Line (AP axis) is perpendicular to the TEA. The femoral shaft axis relates to coronal alignment.

Question 11971

Topic: 2. Trauma

Which complication is more likely with an undersized femoral component in the anterior-posterior dimension?

. Stiffness and loss of flexion
. Anterior impingement of the extensor mechanism
. Posterior instability in flexion
. Fracture of the anterior femoral cortex
. Patellar clunk syndrome

Correct Answer & Explanation

. Posterior instability in flexion

Explanation

An undersized femoral component in the anterior-posterior dimension creates a relatively loose flexion gap. This can lead to posterior instability in flexion, where the femur can subluxate posteriorly on the tibial tray. Stiffness and anterior impingement are more common with oversized or anteriorized components. Fracture of the anterior femoral cortex is a risk with notching during distal femoral cuts. Patellar clunk syndrome has a different etiology.

Question 11972

Topic: 2. Trauma

Which factor is most strongly associated with a higher risk of nonunion following first MTP joint arthrodesis?

. Age greater than 60 years
. Use of a dorsal compression plate for fixation
. Diabetes mellitus and smoking history
. Fusion angle of 10-15 degrees dorsiflexion
. Female gender

Correct Answer & Explanation

. Diabetes mellitus and smoking history

Explanation

Smoking history and diabetes mellitus are well-established systemic risk factors for nonunion in any arthrodesis or fracture fixation, including the first MTP joint. Nicotine impairs vascularity and osteoblast function, and diabetes compromises healing processes. While age, fixation method, and fusion angle can influence outcomes, smoking and diabetes have a significantly higher impact on nonunion rates. The use of a dorsal compression plate typicallyreducesthe risk of nonunion by providing stable fixation.

Question 11973

Topic: 2. Trauma

Which of the following is considered the most common complication following a first MTP joint arthrodesis?

. Infection
. Deep vein thrombosis
. Nonunion or malunion
. Hallux varus deformity
. Hardware failure necessitating removal

Correct Answer & Explanation

. Nonunion or malunion

Explanation

Nonunion or malunion (fusion in an undesirable position) are the most common complications following first MTP joint arthrodesis. While infection and DVT are general surgical risks, the primary challenge of any fusion procedure is achieving solid bony union in the correct alignment. Hardware failure can occur, but often in the context of nonunion. Hallux varus is less common than malunion, especially if careful positioning is achieved.

Question 11974

Topic: 2. Trauma

In a patient presenting with an acute patellar dislocation, extensive edema and ecchymosis around the knee. Which concurrent injury should be specifically ruled out due to its potential for significant morbidity?

. Meniscal tear.
. ACL tear.
. Femoral shaft fracture.
. Neurovascular injury.
. Ligamentous laxity of the MCL.

Correct Answer & Explanation

. Neurovascular injury.

Explanation

While meniscal tears and ACL tears can occur with patellar dislocations, a neurovascular injury is a critical and potentially devastating complication that must be ruled out immediately in an acute, swollen knee following a dislocation (especially knee dislocations, but patellar dislocations can also be associated, or cause compartment syndrome from swelling). Compromise of the popliteal artery or peroneal nerve requires urgent intervention to prevent limb-threatening consequences. Femoral shaft fracture is less common but can be obvious on X-ray. MCL laxity is often present but not limb-threatening.

Question 11975

Topic: Lower Extremity Trauma

The meniscal horns are primarily composed of which type of tissue, contributing to their robust attachment to the tibia?

. Elastic cartilage.
. Hyaline cartilage.
. Dense regular fibrous connective tissue.
. Adipose tissue.
. Loose areolar tissue.

Correct Answer & Explanation

. Dense regular fibrous connective tissue.

Explanation

The anterior and posterior horns of the menisci, where they attach to the tibial plateau, are composed of dense regular fibrous connective tissue. This robust, tendon-like structure allows them to firmly anchor the menisci to the bone, resisting tensile forces and maintaining the meniscal position under load. Disruption of these root attachments severely compromises meniscal function.

Question 11976

Topic: Lower Extremity Trauma

The meniscal extracellular matrix contains a small percentage of elastin fibers. What is their likely functional role?

. Primary load bearing.
. Providing tensile strength to resist tearing.
. Contributing to the elastic recoil and shape recovery of the meniscus.
. Anchoring the meniscal horns to the tibial plateau.
. Facilitating nutrient diffusion into the avascular zones.

Correct Answer & Explanation

. Contributing to the elastic recoil and shape recovery of the meniscus.

Explanation

While collagen provides tensile strength and proteoglycans provide compressive stiffness, the minor component of elastin fibers likely contributes to the elastic recoil properties of the meniscus. This allows the meniscus to deform under load and then return to its original shape, helping it adapt to varying joint configurations and stresses.

Question 11977

Topic: Lower Extremity Trauma

Which meniscal structure is considered the most stable in terms of its attachment to the tibial plateau?

. Anterior horn of the lateral meniscus.
. Posterior horn of the lateral meniscus.
. Anterior horn of the medial meniscus.
. Posterior horn of the medial meniscus.
. Mid-body of the lateral meniscus.

Correct Answer & Explanation

. Posterior horn of the medial meniscus.

Explanation

The posterior horn of the medial meniscus has the broadest and most robust attachment to the tibial plateau, making it the most stable meniscal attachment. This stability is crucial for its role in resisting anterior tibial translation and maintaining the integrity of the medial compartment.

Question 11978

Topic: Lower Extremity Trauma

The specific topographical shape of the menisci (concave superiorly) is critical for:

. Increasing the overall mass of the knee joint.
. Allowing direct nutrient diffusion from synovial fluid.
. Improving the congruity between the femoral condyles and tibial plateau.
. Providing a stable attachment point for the collateral ligaments.
. Reducing the overall joint volume.

Correct Answer & Explanation

. Improving the congruity between the femoral condyles and tibial plateau.

Explanation

The wedge-shaped, concave superior surface of the menisci is crucial for improving the congruity between the convex femoral condyles and the relatively flat tibial plateau. This enhanced congruity effectively increases the contact area across the tibiofemoral joint, thereby distributing loads more evenly and reducing peak contact stresses on the articular cartilage.

Question 11979

Topic: Lower Extremity Trauma

What is the primary function of the meniscotibial ligaments (coronary ligaments)?

. To connect the anterior horns of the menisci.
. To attach the menisci to the femoral condyles.
. To anchor the menisci to the tibial plateau.
. To provide stability to the fibular head.
. To transmit proprioceptive signals from the posterior capsule.

Correct Answer & Explanation

. To anchor the menisci to the tibial plateau.

Explanation

The meniscotibial ligaments, also known as the coronary ligaments, are capsular attachments that anchor the peripheral borders of the menisci to the tibial plateau. These attachments provide stability to the menisci, limiting their excessive displacement during knee movement, though they allow for some degree of physiological translation.

Question 11980

Topic: Lower Extremity Trauma

The meniscal 'white-white' zone is characterized by:

. High vascularity and cellularity.
. Lack of blood supply and poor healing capacity.
. Predominance of elastic fibers.
. Strongest mechanical attachment to the tibial plateau.
. High concentration of Pacinian corpuscles.

Correct Answer & Explanation

. Lack of blood supply and poor healing capacity.

Explanation

The 'white-white zone' refers to the inner two-thirds (or more) of the meniscal body that is completely avascular. This lack of blood supply means that tears in this region have extremely poor to non-existent intrinsic healing capacity, making surgical repair generally unsuccessful.

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