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2. Trauma MCQs

Practice Set 478 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 9541

Topic: 2. Trauma

Which of the following locations is the most common site for a chondroblastoma to arise in a skeletally immature patient?

. Diaphysis of the humerus
. Metaphysis of the distal femur
. Epiphysis of the distal femur
. Cortex of the proximal tibia
. Medullary canal of the distal radius

Correct Answer & Explanation

. Epiphysis of the distal femur

Explanation

Chondroblastomas almost exclusively arise in the epiphyses (or apophyses, like the greater trochanter) of long bones in skeletally immature patients. The distal femur, proximal tibia, and proximal humerus are the most common locations.

Question 9542

Topic: 2. Trauma

Which of the following clinical presentations is the most common initial symptom in a patient with a chondroblastoma?

. Pathologic fracture through the diaphysis
. Painless, enlarging palpable mass
. Joint pain and a sympathetic effusion
. Systemic symptoms including fever and night sweats
. Neurologic deficit secondary to nerve compression

Correct Answer & Explanation

. Joint pain and a sympathetic effusion

Explanation

Because chondroblastomas are located in the epiphysis close to the articular surface, they most commonly present with joint pain, decreased range of motion, and a secondary sympathetic joint effusion. Pathologic fractures are rare.

Question 9543

Topic: 2. Trauma

Which of the following is the most common anatomic location for the development of a chondroblastoma?

. Diaphysis of the humerus
. Metaphysis of the distal femur
. Epiphysis of the proximal tibia
. Epiphysis of the distal femur
. Diaphysis of the tibia

Correct Answer & Explanation

. Epiphysis of the distal femur

Explanation

Chondroblastomas almost exclusively arise in the epiphyses or apophyses of long bones in skeletally immature patients. The distal femur epiphysis is the single most common site, followed by the proximal tibia and proximal humerus.

Question 9544

Topic: 2. Trauma

A 25-year-old patient is incidentally found to have striking widening of the metaphyses of the long bones, particularly the distal femur and proximal tibia, resembling an 'Erlenmeyer flask'. The patient is of normal height and has no significant clinical symptoms other than mild genu valgum. What is the most likely diagnosis?

. Achondroplasia
. Osteopetrosis
. Pyle disease
. Jansen metaphyseal chondrodysplasia
. Multiple hereditary exostoses

Correct Answer & Explanation

. Pyle disease

Explanation

Correct Answer: Pyle diseasePyle disease (familial metaphyseal dysplasia) is characterized by massive metaphyseal expansion (Erlenmeyer flask deformity) due to a defect in metaphyseal remodeling. Unlike craniometaphyseal dysplasia, cranial nerve palsies are rare, and patients typically have normal stature and are often asymptomatic, though they may have mild genu valgum or a slightly increased risk of fractures.

Question 9545

Topic: Lower Extremity Trauma

A 12-year-old presents for evaluation of genu valgum. Radiographs reveal massive cortical thinning and an "Erlenmeyer flask" deformity of the distal femur and proximal tibia metaphyses. The patient's stature is normal, and cranial nerves are completely intact. What is the most likely diagnosis?

. Craniometaphyseal dysplasia
. Pyle disease
. Metaphyseal chondrodysplasia, Schmid type
. Osteopetrosis
. Gaucher disease

Correct Answer & Explanation

. Pyle disease

Explanation

Pyle disease (familial metaphyseal dysplasia) is characterized by striking metaphyseal widening (Erlenmeyer flask deformity) with cortical thinning. Unlike craniometaphyseal dysplasia, Pyle disease typically spares the skull and cranial nerves.

Question 9546

Topic: 2. Trauma
Langerhans cell histiocytosis can present in various clinical forms. Which of the following triads classically defines Hand-Schüller-Christian disease?
. Exophthalmos, diabetes insipidus, and lytic skull lesions
. Hepatosplenomegaly, seborrheic skin rash, and fatal pancytopenia
. Vertebra plana, cafe-au-lait macules, and precocious puberty
. Solitary bone lesion, pathological fracture, and elevated ESR
. Blue sclerae, dentinogenesis imperfecta, and multiple fractures

Correct Answer & Explanation

. Exophthalmos, diabetes insipidus, and lytic skull lesions

Explanation

Hand-Schüller-Christian disease is the chronic disseminated form of Langerhans cell histiocytosis. It is classically characterized by the triad of exophthalmos, diabetes insipidus (due to pituitary involvement), and multiple lytic skull lesions.

Question 9547

Topic: 2. Trauma
An 18-month-old infant is noted to have anterolateral bowing of the left tibia. She also has multiple café-au-lait spots and axillary freckling. What is the most appropriate initial orthopedic management to prevent progression to pseudoarthrosis?
. Immediate Ilizarov bone transport
. Observation with serial radiographs
. Total contact bracing (clamshell orthosis)
. Prophylactic osteotomy and intramedullary nailing
. Vascularized fibular autograft

Correct Answer & Explanation

. Total contact bracing (clamshell orthosis)

Explanation

Anterolateral bowing of the tibia is associated with Neurofibromatosis Type 1 (NF1). The standard of care before a fracture occurs is full-time total contact bracing (clamshell brace) to protect the tibia from fracturing and progressing to recalcitrant pseudoarthrosis.

Question 9548

Topic: 2. Trauma

When performing an olecranon osteotomy for distal humerus fracture exposure, what is the preferred method of fixation for the osteotomized olecranon fragment?

. Absorbable sutures alone
. A single lag screw
. Tension band wiring
. Plate and screw fixation
. External fixation

Correct Answer & Explanation

. Tension band wiring

Explanation

Tension band wiring (TBW) is the most commonly employed and biomechanically sound method for fixing a Chevron or oblique olecranon osteotomy. It converts the distraction forces of the triceps into compression at the fracture site during elbow flexion, promoting healing and stability. While small plates can be used, particularly for more comminuted olecranon fractures, TBW is standard for simple osteotomies. Sutures are inadequate, a single lag screw does not provide rotational stability or sufficient compression under triceps pull, and external fixation is not typically used for this purpose.

Question 9549

Topic: 2. Trauma

What is a common complication of early, aggressive passive range of motion (PROM) following ORIF of a distal humerus fracture, especially in the context of perioperative hematoma or extensive soft tissue dissection?

. Nonunion
. Infection
. Heterotopic ossification
. Hardware loosening
. Ulnar nerve irritation

Correct Answer & Explanation

. Heterotopic ossification

Explanation

Aggressive, unguided passive range of motion, particularly in the presence of extensive soft tissue injury, periosteal stripping, or hematoma, is a significant risk factor for the development of heterotopic ossification (HO) around the elbow. HO causes severe stiffness and pain. While hardware loosening or ulnar nerve irritation can occur, HO is a more direct and common consequence of overly aggressive PROM in the early postoperative period, especially without proper prophylaxis. Nonunion is a failure of bone healing and infection is a separate entity.

Question 9550

Topic: 2. Trauma

In the management of a complex distal humerus fracture in a young, active patient, what is the primary goal of surgical fixation?

. To achieve anatomical union regardless of joint function
. To allow early, stable range of motion (ESROM) to prevent stiffness
. To minimize surgical time and blood loss
. To obtain a cosmetically acceptable result
. To reduce the need for future revision surgery

Correct Answer & Explanation

. To allow early, stable range of motion (ESROM) to prevent stiffness

Explanation

For distal humerus fractures, especially intra-articular ones, the primary goal of surgical fixation in active patients is to achieve a stable construct that allows for early, stable range of motion (ESROM). This is crucial for preventing debilitating elbow stiffness, which is a common and often difficult-to-treat complication. Anatomical reduction and rigid fixation are means to this end. While minimizing surgical time and reducing future revision are desirable, they are secondary to achieving functional outcomes and preventing stiffness. Cosmetic results are generally not the primary concern for this type of injury.

Question 9551

Topic: 2. Trauma

A 28-year-old male sustains a traumatic distal humerus fracture. He is hemodynamically stable, but his elbow is markedly swollen. Prior to surgical planning, what initial management step is essential to ensure adequate soft tissue conditions for surgery?

. Immediate traction and reduction in the operating room
. Application of a compressive bandage to reduce swelling
. Elevation, ice, and gentle splinting in a comfortable position
. Aggressive steroid administration to reduce inflammation
. Passive range of motion exercises

Correct Answer & Explanation

. Elevation, ice, and gentle splinting in a comfortable position

Explanation

For acute, significantly swollen elbow fractures, initial management should focus on reducing swelling to optimize soft tissue conditions for surgery. This involves elevation, ice, and gentle splinting in a comfortable position (often 90 degrees of flexion to relax the triceps and biceps). Operating through severely swollen soft tissues increases the risk of wound complications, infection, and poor healing. Compressive bandages can exacerbate swelling or even cause compartment syndrome. Immediate traction/reduction is not indicated without adequate soft tissue preparation. Steroids are not typically used. Passive ROM is contraindicated acutely.

Question 9552

Topic: 2. Trauma

What is the typical timeframe for initiating active range of motion (AROM) exercises following stable ORIF of a distal humerus fracture?

. Immediately post-op (Day 0-1)
. After 6-8 weeks of rigid immobilization
. Within the first week post-op (Day 3-7)
. Only after radiographic signs of complete union (3-4 months)
. Not until all hardware is removed

Correct Answer & Explanation

. Within the first week post-op (Day 3-7)

Explanation

With stable open reduction and internal fixation (ORIF) of a distal humerus fracture, the goal is often to initiate early active range of motion (AROM) exercises within the first week post-operatively (typically Day 3-7). This helps to prevent elbow stiffness, which is a major complication. Prolonged rigid immobilization (6-8 weeks) is often detrimental to elbow motion. Immediate post-op ROM may be too early due to pain and swelling, but delayed initiation waits too long. Complete union takes months, and waiting for hardware removal is excessively delayed.

Question 9553

Topic: 2. Trauma

What is the primary concern when considering non-operative management for a distal humerus fracture?

. Risk of infection
. Development of heterotopic ossification
. Potential for malunion or nonunion with functional deficit
. Ulnar nerve entrapment
. DVT and PE

Correct Answer & Explanation

. Potential for malunion or nonunion with functional deficit

Explanation

For most displaced or intra-articular distal humerus fractures, non-operative management carries a significant risk of malunion or nonunion, leading to poor functional outcomes, pain, and stiffness. This is the primary reason why ORIF is often preferred. Non-operative management is typically reserved for truly nondisplaced or minimally displaced fractures in low-demand patients, or in those unfit for surgery. While other complications can occur, malunion/nonunion with severe functional deficit is the most direct consequence of inadequate stabilization in non-operative treatment of unstable fractures.

Question 9554

Topic: 2. Trauma
Which of the following historical classifications for distal humerus fractures specifically emphasizes the separation of the articular segment from the metaphysis and the degree of articular comminution?
. AO/OTA classification
. Jupiter classification (for unicondylar fractures)
. Riseborough and Radin classification
. Bryan and Morrey classification (for capitellar fractures)
. Gustilo-Anderson classification

Correct Answer & Explanation

. Riseborough and Radin classification

Explanation

The Riseborough and Radin classification (Types I-IV) specifically addresses the relationship between the articular segment and the metaphysis, and the degree of articular comminution for intercondylar distal humerus fractures.

Question 9555

Topic: Upper Extremity Trauma

What is the typical position of the elbow for applying a posterior approach with an olecranon osteotomy during distal humerus fracture repair?

. Full extension
. Full flexion
. Semi-flexion (approximately 30 degrees)
. Flexion to 90 degrees
. Variable, depending on surgeon preference

Correct Answer & Explanation

. Flexion to 90 degrees

Explanation

For a posterior approach with an olecranon osteotomy, the elbow is typically positioned in approximately 90 degrees of flexion. This allows for optimal exposure of the posterior distal humerus, provides access to the ulnar nerve, and facilitates the performance and subsequent fixation of the olecranon osteotomy. It also puts the triceps under slight tension which can aid in dissection. Full extension or full flexion might hinder certain steps of the exposure or reduction.

Question 9556

Topic: 2. Trauma

Which of the following complications is most commonly associated with a triceps-splitting posterior approach for distal humerus fractures, compared to an olecranon osteotomy approach?

. Increased risk of nonunion of the fracture
. Higher incidence of ulnar nerve injury
. More difficult and limited visualization of the articular surface
. Greater risk of heterotopic ossification
. Longer rehabilitation period

Correct Answer & Explanation

. More difficult and limited visualization of the articular surface

Explanation

While triceps-splitting approaches (e.g., triceps-reflecting or triceps-sparing) avoid an olecranon osteotomy, their primary drawback for complex intra-articular fractures is often a more limited visualization of the articular surface, especially compared to the panoramic view afforded by an olecranon osteotomy. This can make accurate anatomical reduction of comminuted articular fragments more challenging. Nonunion risk, HO, ulnar nerve injury, and rehab time are more broadly associated with distal humerus surgery, but limited exposure is a specific relative disadvantage of avoiding osteotomy in complex cases.

Question 9557

Topic: 2. Trauma

What is the surgical principle behind using two plates applied in an orthogonal fashion (medial and posterior/posterolateral) for bicondylar distal humerus fractures?

. To allow for less rigid fixation for earlier bone healing
. To facilitate primary bone healing by maximizing interfragmentary compression
. To buttress both columns and resist forces in multiple planes (torsion, varus/valgus, bending)
. To simplify plate contouring and application
. To reduce the overall weight of the implant construct

Correct Answer & Explanation

. To buttress both columns and resist forces in multiple planes (torsion, varus/valgus, bending)

Explanation

Orthogonal plating for bicondylar distal humerus fractures is designed to buttress both the medial and lateral columns (using a medial plate and a posterior/posterolateral plate) and to resist forces in multiple planes. This construct provides robust stability against axial, varus/valgus, and torsional stresses, which is crucial for complex comminuted fractures to allow early range of motion. It maximizes the biomechanical stability of the construct, rather than intentionally reducing rigidity. While interfragmentary compression is important, the primary principle of orthogonal plating is multiplanar stability. It does not simplify contouring or reduce implant weight.

Question 9558

Topic: 2. Trauma

Regarding rehabilitation after ORIF of a distal humerus fracture, what is a key goal in the early phase (first 2-4 weeks)?

. Achieve full elbow extension (>0 degrees)
. Regain full grip strength
. Maintain stable fixation while regaining controlled active and passive ROM
. Begin resisted strengthening exercises
. Discontinue all pain medication

Correct Answer & Explanation

. Maintain stable fixation while regaining controlled active and passive ROM

Explanation

In the early phase (first 2-4 weeks) after stable ORIF of a distal humerus fracture, the key goal is to maintain the stable fixation achieved surgically while carefully initiating controlled active and passive range of motion (ROM) within pain limits. This helps prevent stiffness without jeopardizing healing. Achieving full elbow extension or full grip strength are later goals. Resisted strengthening exercises are introduced much later (typically 6-12 weeks). Discontinuing all pain medication is a patient-driven goal, not a rehabilitation phase goal.

Question 9559

Topic: Upper Extremity Trauma

What is the typical anatomical location of the primary blood supply to the distal humerus?

. Branches from the anterior humeral circumflex artery
. The nutrient artery originating from the brachial artery, entering proximally
. Direct branches from the ulnar collateral arteries
. The posterior interosseous artery
. The recurrent radial artery

Correct Answer & Explanation

. The nutrient artery originating from the brachial artery, entering proximally

Explanation

The primary blood supply to the distal humerus, as with the rest of the humerus, typically comes from the nutrient artery, a branch of the brachial artery, which enters the shaft proximally and sends branches distally. Additional supply comes from periosteal vessels and contributions from collateral arteries (superior ulnar collateral, inferior ulnar collateral, radial collateral) that form an anastomotic network around the elbow. The anterior humeral circumflex artery supplies the proximal humerus. The posterior interosseous and recurrent radial arteries are primarily forearm vessels.

Question 9560

Topic: 2. Trauma

A 40-year-old construction worker presents with a comminuted intra-articular distal humerus fracture, classified as a Type C3 fracture by AO/OTA. He has no neurovascular deficits. Given his age and occupation, which factor is most crucial for achieving an excellent outcome?

. Minimizing surgical blood loss
. Preserving periosteal blood supply during exposure
. Achieving anatomical reduction of the articular surface and rigid internal fixation
. Early discharge from the hospital
. Prolonged immobilization to ensure bone healing

Correct Answer & Explanation

. Achieving anatomical reduction of the articular surface and rigid internal fixation

Explanation

For an active, young patient with a complex intra-articular distal humerus fracture, achieving anatomical reduction of the articular surface and rigid internal fixation is paramount. This allows for stable early motion and optimizes the chances of restoring joint congruity and function, directly correlating with an excellent functional outcome and return to pre-injury activity. While preserving periosteal blood supply is important for healing, and minimizing blood loss is good surgical practice, they are subservient to achieving the primary goal of anatomical and stable fixation. Prolonged immobilization would lead to severe stiffness, and early discharge is a logistical, not a functional, outcome determinant.

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