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2. Trauma MCQs

Practice Set 75 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 1481

Topic: 2. Trauma
A 28-year-old male presents with an acetabular fracture after a motorcycle accident. CT scan reveals a posterior wall fracture involving 30% of the articular surface. There is a 3 mm articular step-off, and the hip joint is concentrically reduced and stable on examination. No intra-articular fragments are noted. Based on the provided case information and the teaching material, which of the following is the most appropriate management strategy?
. Non-operative management with protected weight-bearing
. Urgent closed reduction and spica cast
. Open reduction and internal fixation (ORIF)
. Primary total hip arthroplasty
. Delayed ORIF after 4 weeks

Correct Answer & Explanation

. Open reduction and internal fixation (ORIF)

Explanation

The correct answer is open reduction and internal fixation (ORIF). A primary indication for operative management is intra-articular displacement of ≥ 2 mm (some argue for 1 mm in younger patients in the weight-bearing dome). In this vignette, the patient has a 3 mm articular step-off, which exceeds the 2 mm threshold, making operative management indicated despite the hip being stable and the posterior wall involvement (30%) being below the 40-50% threshold for inherent instability. Non-operative management is reserved for displacements less than 2 mm.

Question 1482

Topic: 2. Trauma

A 55-year-old patient sustains a complex acetabular fracture after a fall from height. Initial plain radiographs (AP pelvis, iliac oblique, and obturator oblique views) are obtained, which help classify the fracture according to Judet and Letournel. However, the surgeon requires more detailed information for definitive diagnosis and meticulous surgical planning. According to the case, which imaging modality is considered essential for this purpose?

. MRI with contrast
. Ultrasound
. Thin-slice CT with 2D and 3D reconstructions
. Bone scintigraphy
. Standard plain radiographs only

Correct Answer & Explanation

. Thin-slice CT with 2D and 3D reconstructions

Explanation

Correct Answer: CThe correct answer isThin-slice CT with 2D and 3D reconstructions. The 'Pre-Operative Planning & Patient Positioning' section, under 'Imaging Analysis,' explicitly states that 'Computed Tomography (CT) Scan:Essentialfor definitive diagnosis and surgical planning.' It further elaborates that 'Thin-slice CT with 2D and 3D Reconstructions provides detailed visualization of fracture lines, comminution, articular step-off, intra-articular fragments, quadrilateral surface involvement, and femoral head integrity. It is invaluable for understanding fracture morphology and choosing the appropriate surgical approach.' While plain radiographs are initial and help classify, they lack the detail needed for surgical planning. MRI is rarely indicated acutely unless specific soft tissue or chondral injuries are suspected. Ultrasound and bone scintigraphy have no primary role in acute acetabular fracture diagnosis and surgical planning.

Question 1483

Topic: 2. Trauma

A 30-year-old patient underwent open reduction and internal fixation for a transverse acetabular fracture 5 years ago. Despite initial good recovery and radiographic evidence of fracture union, he now presents with progressive hip pain, stiffness, and radiographic findings of joint space narrowing, subchondral sclerosis, and osteophytes. Based on the long-term outcomes discussed in the case, what is the most likely underlying cause of this patient's current symptoms and radiographic findings?

. Avascular necrosis of the femoral head
. Hardware failure
. Heterotopic ossification
. Post-traumatic osteoarthritis
. Nonunion of the fracture

Correct Answer & Explanation

. Post-traumatic osteoarthritis

Explanation

Correct Answer: DThe correct answer isPost-traumatic osteoarthritis (PTOA). The 'Complications & Management' section identifies PTOA as a very common long-term complication (20-80% incidence), described as 'Progressive degeneration of the articular cartilage, leading to pain, stiffness, and functional limitation. Directly correlated with quality of reduction.' The symptoms of progressive hip pain, stiffness, and radiographic findings of joint space narrowing, subchondral sclerosis, and osteophytes are classic signs of osteoarthritis. While AVN, hardware failure, HO, and nonunion are possible complications, the clinical presentation and radiographic findings described are most consistent with PTOA, especially given the 5-year post-operative timeframe and initial fracture union.

Question 1484

Topic: 2. Trauma

A 25-year-old patient underwent open reduction and internal fixation of a posterior column acetabular fracture. The surgeon emphasizes strict adherence to the post-operative protocol to protect the fixation and promote healing. In the immediate post-operative phase (weeks 0-6), which of the following weight-bearing and range of motion guidelines is generally recommended for this patient?

. Full weight-bearing as tolerated
. Partial weight-bearing with crutches
. Non-weight bearing (NWB) on the operative extremity
. Unrestricted active range of motion
. Deep hip flexion beyond 90 degrees

Correct Answer & Explanation

. Non-weight bearing (NWB) on the operative extremity

Explanation

Correct Answer: CThe correct answer isNon-weight bearing (NWB) on the operative extremity. The 'Post-Operative Rehabilitation Protocols' section, under 'Phase Immediate Post-Operative (Weeks 0-6),' clearly states for weight-bearing: 'Non-Weight Bearing (NWB) on the operative extremity. Ambulation with crutches or a walker. Foot-flat weight-bearing or toe-touch weight-bearing (TTWB) may be allowed by some surgeons for stability, but NWB is generally safer.' Regarding range of motion, it advises 'Active-Assisted ROM (AAROM) and Gentle Passive ROM (PROM): Within pain limits. Avoid extremes of motion, especially positions that stress the fracture fragments (e.g., deep flexion, adduction, internal rotation for posterior fractures).' Therefore, full or partial weight-bearing and unrestricted or deep hip flexion are not appropriate in this immediate phase.

Question 1485

Topic: 2. Trauma

A 28-year-old male presents with a posterior hip dislocation after a fall from height. Initial AP and lateral radiographs confirm the dislocation. However, the lateral view also raises suspicion for an ipsilateral femoral neck fracture. Given this finding, which of the following is the most appropriate next step in management?

. Proceed immediately with closed reduction under conscious sedation.
. Attempt a gentle Stimson maneuver to reduce the hip.
. Obtain a pre-reduction CT scan of the hip and pelvis.
. Administer intravenous muscle relaxants and analgesia, then attempt Bigelow maneuver.
. Prepare for immediate open reduction and internal fixation of the hip dislocation.

Correct Answer & Explanation

. Obtain a pre-reduction CT scan of the hip and pelvis.

Explanation

Correct Answer: CThe case explicitly states, "Absolute contraindications toattempting closed reductionare rare but include:Femoral neck fracture:This is a crucial contraindication. Attempting closed reduction in the presence of an ipsilateral femoral neck fracture can convert a non-displaced fracture into a displaced one, or cause further displacement, increasing the risk of AVN or nonunion. This requires careful pre-reduction imaging." Therefore, before any reduction attempt, a CT scan is essential to definitively rule out or characterize a femoral neck fracture, which would necessitate operative management.

Question 1486

Topic: 2. Trauma

A 25-year-old athlete presents with an acute posterior hip dislocation. The emergency physician is preparing for closed reduction. Which of the following principles is paramount for a safe and successful reduction, regardless of the specific maneuver chosen?

. Rapid, forceful internal rotation to disengage the femoral head.
. Application of a direct posterior force to the greater trochanter.
. Adequate muscle relaxation and sustained axial traction.
. Immediate post-reduction weight-bearing to confirm stability.
. Avoiding any hip flexion beyond 45 degrees during the maneuver.

Correct Answer & Explanation

. Adequate muscle relaxation and sustained axial traction.

Explanation

Correct Answer: CThe case clearly outlines the key principles for emergency closed reduction: "Regardless of the specific maneuver, key principles apply: 1.Adequate Muscle Relaxation:Absolutely paramount. Without it, forceful reduction attempts can lead to iatrogenic fractures or cartilage damage. 2.Axial Traction:Apply steady, sustained axial traction in line with the femoral shaft, aiming to distract the femoral head from the acetabulum." Forceful maneuvers without adequate relaxation increase the risk of iatrogenic injury. Hip flexion (often 60-90 degrees) is typically used to relax the powerful hip flexors and iliofemoral ligament, making option E incorrect. Immediate post-reduction weight-bearing is not recommended, especially for complex dislocations.

Question 1487

Topic: 2. Trauma

A 30-year-old male underwent open reduction and internal fixation of a posterior hip dislocation with an associated posterior acetabular wall fracture. He is now 3 days post-operative. Which of the following is the most appropriate initial weight-bearing and range of motion protocol for this patient?

. Full weight-bearing as tolerated, avoiding hip flexion beyond 90 degrees.
. Touchdown weight-bearing with crutches, unrestricted hip range of motion.
. Strict non-weight-bearing for 6-12 weeks, with gentle, protected passive range of motion.
. Continuous passive motion (CPM) machine with full hip flexion and internal rotation.
. Partial weight-bearing (50%) with a walker, avoiding hip abduction.

Correct Answer & Explanation

. Strict non-weight-bearing for 6-12 weeks, with gentle, protected passive range of motion.

Explanation

Correct Answer: CThe case details post-operative rehabilitation: "Open Reduction / Associated Fractures (e.g., posterior wall):Strict non-weight-bearing (NWB) for 6-12 weeks, depending on fracture stability, hardware, and surgeon preference. This protects the healing capsule, repaired soft tissues, and any internal fixation.Range of Motion (ROM):Gentle, pain-free ROM within protective limits. Avoid the 'dislocating position' (flexion > 90°, adduction, internal rotation)." Full or partial weight-bearing would jeopardize the healing fracture and fixation. Unrestricted ROM or full flexion/internal rotation would risk re-dislocation or damage to the repair. Therefore, strict NWB with protected ROM is the safest initial approach.

Question 1488

Topic: 2. Trauma

A 78-year-old female undergoes a reverse total shoulder arthroplasty for a complex 4-part proximal humerus fracture. Healing of the greater tuberosity to the proximal humerus shaft and prosthesis is most highly associated with improved outcomes in which of the following postoperative clinical parameters?

. Forward elevation
. Internal rotation
. External rotation
. Scapular retraction
. Adduction

Correct Answer & Explanation

. External rotation

Explanation

In reverse shoulder arthroplasty for fractures, the deltoid reliably restores forward elevation regardless of tuberosity healing. However, anatomical healing of the greater tuberosity (which houses the infraspinatus and teres minor) is crucial for restoring active external rotation and maximizing functional scores.

Question 1489

Topic: 2. Trauma

Radiographic evaluation of an acetabular fracture reveals disruption of the iliopectineal line, the ilioischial line, and an inferior fracture line splitting the obturator ring. However, a portion of the articular surface remains attached to the axial skeleton via an intact posterior ilium. This fracture is best classified as:

. Associated both-column
. T-type
. Transverse with posterior wall
. Anterior column with posterior hemitransverse
. Pure transverse

Correct Answer & Explanation

. T-type

Explanation

A T-type fracture involves a transverse fracture through both columns combined with an inferior vertical split through the obturator ring. Because a portion of the articular roof remains attached to the intact posterior ilium, it is excluded from being an associated both-column fracture.

Question 1490

Topic: 2. Trauma

A 28-year-old male sustains an isolated posterior wall acetabular fracture after a motor vehicle collision. The hip joint is congruously reduced on static radiographs. Which of the following is the most definitive indication for open reduction and internal fixation of this fracture?

. Fragment size greater than 10% of the posterior wall
. Presence of a marginal impaction fragment
. Dynamic instability on fluoroscopic stress examination under anesthesia
. Concomitant non-displaced pubic ramus fracture
. Mild sciatic nerve neurapraxia

Correct Answer & Explanation

. Dynamic instability on fluoroscopic stress examination under anesthesia

Explanation

The absolute indication for surgical fixation of a posterior wall acetabular fracture is hip joint instability. While fragment size greater than 20-50% suggests instability, dynamic fluoroscopic stress testing under anesthesia is the most accurate and definitive method to determine the need for surgery.

Question 1491

Topic: 2. Trauma

Which of the following represents the strongest radiographic predictor of humeral head ischemia following a displaced proximal humerus fracture, according to Hertel's criteria?

. Metaphyseal head extension > 8 mm
. Medial hinge displacement > 2 mm
. Greater tuberosity displacement > 5 mm
. Head-shaft angulation > 20 degrees
. Fracture extension into the bicipital groove

Correct Answer & Explanation

. Medial hinge displacement > 2 mm

Explanation

According to Hertel's criteria, the disruption of the medial hinge (displacement > 2 mm) and a short calcar segment attached to the articular fragment (< 8 mm metaphyseal extension) are highly predictive of humeral head ischemia.

Question 1492

Topic: Pelvic & Acetabular Trauma

On an anteroposterior (AP) radiograph of the pelvis, which underlying anatomic structure is defined by the iliopectineal line?

. Anterior column
. Posterior column
. Anterior wall
. Posterior wall
. Quadrilateral surface

Correct Answer & Explanation

. Anterior column

Explanation

The iliopectineal line represents the anterior column of the acetabulum on an AP pelvic radiograph. Disruption of this line indicates a fracture involving the anterior column.

Question 1493

Topic: 2. Trauma

A patient with an acetabular fracture has an obturator oblique radiograph demonstrating a pathognomonic "spur sign". What does this specific radiographic finding represent?

. Displacement of the quadrilateral plate medially
. Comminution of the posterior wall
. The lowest portion of the intact ilium attached to the axial skeleton
. An extruded fragment of the sciatic buttress
. A transverse fracture component exiting the greater sciatic notch

Correct Answer & Explanation

. The lowest portion of the intact ilium attached to the axial skeleton

Explanation

The "spur sign" on an obturator oblique view is pathognomonic for an associated both-column acetabular fracture. It represents the lowest piece of the intact ilium that remains solidly attached to the axial skeleton.

Question 1494

Topic: 2. Trauma

A 78-year-old female sustains a displaced 4-part proximal humerus fracture with significant tuberosity comminution and marked osteopenia. To maximize reliable active forward elevation, which of the following is the most appropriate surgical intervention?

. Open reduction and internal fixation with locking plates
. Hemiarthroplasty
. Reverse total shoulder arthroplasty
. Closed reduction and percutaneous pinning
. Intramedullary nailing

Correct Answer & Explanation

. Reverse total shoulder arthroplasty

Explanation

Reverse total shoulder arthroplasty is indicated for elderly patients with complex 4-part proximal humerus fractures and poor bone stock. It bypasses the need for tuberosity healing to achieve active forward elevation by relying on the deltoid.

Question 1495

Topic: 2. Trauma

On the anteroposterior (AP) radiograph of the pelvis, a pure transverse fracture of the acetabulum will characteristically disrupt which of the following lines?

. Iliopectineal line only
. Ilioischial line only
. Both the iliopectineal and ilioischial lines
. The posterior wall margin only
. The anterior wall margin only

Correct Answer & Explanation

. Both the iliopectineal and ilioischial lines

Explanation

A transverse acetabular fracture crosses the acetabulum horizontally, dividing the innominate bone into upper and lower halves. Consequently, it involves and disrupts both the anterior (iliopectineal line) and posterior (ilioischial line) columns.

Question 1496

Topic: 2. Trauma

During open reduction and internal fixation of a proximal humerus fracture with a locked plate, which intraoperative step is most essential for preventing the most common hardware-related complication?

. Placing the plate at least 3 cm distal to the greater tuberosity
. Using a dynamic screw for initial compression
. Obtaining dynamic fluoroscopic views through a full range of motion
. Utilizing bicortical screw purchase for all proximal locking screws
. Releasing the coracoacromial ligament

Correct Answer & Explanation

. Obtaining dynamic fluoroscopic views through a full range of motion

Explanation

The most common hardware-related complication of locked plating in the proximal humerus is primary or secondary intra-articular screw penetration. Dynamic fluoroscopy through a full range of motion is critical to detect unrecognized primary screw penetration.

Question 1497

Topic: 2. Trauma

During hemiarthroplasty for a comminuted proximal humerus fracture, restoring proper prosthesis height is critical. The superior border of the pectoralis major tendon insertion is consistently located at what distance distal to the superior aspect of the native humeral head?

. 1.5 cm
. 3.2 cm
. 5.6 cm
. 7.8 cm
. 9.0 cm

Correct Answer & Explanation

. 5.6 cm

Explanation

The superior border of the pectoralis major insertion is a highly reliable anatomic landmark in complex proximal humerus fractures. It is located approximately 5.6 cm distal to the superior aspect of the articular surface of the humeral head.

Question 1498

Topic: 2. Trauma

A 65-year-old female sustains a three-part proximal humerus fracture. The treating surgeon evaluates the radiographs to determine the risk of humeral head ischemia. According to Hertel's criteria, which of the following findings is the most reliable predictor of subsequent avascular necrosis?

. Metaphyseal head extension < 8 mm
. Medial hinge disruption < 2 mm
. Varus angulation of 15 degrees
. Greater tuberosity displacement > 5 mm
. Lesser tuberosity displacement > 1 cm

Correct Answer & Explanation

. Metaphyseal head extension < 8 mm

Explanation

Hertel's criteria identify metaphyseal head extension (calcar length) < 8 mm, disruption of the medial hinge > 2 mm, and a basicervical fracture pattern as strong predictors of humeral head ischemia. A short calcar segment indicates loss of crucial blood supply from the ascending branch of the anterior humeral circumflex artery.

Question 1499

Topic: 2. Trauma

A 50-year-old male undergoes open reduction and internal fixation of a proximal humerus fracture using a proximal humeral locking plate. At his 6-month follow-up, he complains of mechanical catching and pain during shoulder abduction. Radiographs show severe joint space narrowing and glenoid erosion. What is the most common complication of this specific surgical intervention?

. Axillary nerve palsy
. Humeral head avascular necrosis
. Intra-articular screw penetration
. Nonunion
. Deep infection

Correct Answer & Explanation

. Intra-articular screw penetration

Explanation

Intra-articular screw penetration is the most common complication following locked plating of proximal humerus fractures, often due to settling of the fracture or unrecognized penetration during surgery. It rapidly leads to secondary glenoid cartilage destruction if not promptly addressed.

Question 1500

Topic: 2. Trauma

A trauma patient is undergoing radiographic evaluation for a suspected acetabular fracture. The surgeon orders standard AP pelvis and Judet views. On the iliac oblique view of the pelvis, which primary radiographic landmark is best evaluated?

. Anterior column
. Posterior wall
. Posterior column
. Iliopectineal line
. Ischial spine

Correct Answer & Explanation

. Posterior column

Explanation

The iliac oblique view primarily profiles the posterior column and the anterior wall of the acetabulum. Conversely, the obturator oblique view best demonstrates the anterior column and the posterior wall.

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