Menu

Question 1461

Topic: 2. Trauma

A 45-year-old male presents after a motor vehicle collision with an acetabular fracture. Radiographs and CT demonstrate a fracture line separating the anterior half of the ilium and the anterior wall from the intact posterior ilium, exiting through the obturator ring, combined with a transverse fracture through the posterior column. A portion of the posterior articular surface remains attached to the intact axial skeleton. What is the Letournel classification of this fracture pattern?

. T-type
. Transverse
. Anterior column with posterior hemitransverse
. Both column
. Associated both column

Correct Answer & Explanation

. Anterior column with posterior hemitransverse


Explanation

This pattern describes an anterior column with posterior hemitransverse fracture. It differs from a both-column fracture because a portion of the articular surface (usually posterior) remains attached to the intact axial skeleton.

Question 1462

Topic: 2. Trauma
A 25-year-old male sustains a vertically oriented (Pauwels type III) femoral neck fracture. To maximize biomechanical stability and reduce the risk of varus collapse and nonunion, which of the following fixation constructs is most appropriate?
. Three parallel cannulated screws
. Dynamic hip screw (DHS) with a derotational screw
. Cephalomedullary nail
. Bipolar hemiarthroplasty
. Multiple unthreaded Steinmann pins

Correct Answer & Explanation

. Dynamic hip screw (DHS) with a derotational screw


Explanation

For unstable, vertically oriented Pauwels type III femoral neck fractures in young adults, a fixed-angle device such as a sliding hip screw (DHS) with an anti-rotation screw provides superior biomechanical stability. It better resists the high vertical shear forces and prevents varus collapse compared to parallel cannulated screws.

Question 1463

Topic: 2. Trauma

A 32-year-old female presents with a distal femur fracture following a high-energy trauma. CT imaging reveals a coronal plane fracture of the lateral femoral condyle. Which of the following is the most appropriate biomechanical fixation technique for this specific fracture fragment?

. Anterior-to-posterior lag screws placed outside the articular cartilage
. Posterior-to-anterior lag screws placed through the articular cartilage
. A laterally based locking plate without independent lag screws
. Intramedullary nailing utilizing distal interlocking screws
. External fixation spanning the knee joint

Correct Answer & Explanation

. Anterior-to-posterior lag screws placed outside the articular cartilage


Explanation

A Hoffa fracture is a coronal shear fracture of the femoral condyle. Anterior-to-posterior (AP) lag screws placed perpendicular to the fracture plane offer superior biomechanical fixation compared to PA screws and should be countersunk if placed through articular cartilage.

Question 1464

Topic: 2. Trauma
A 40-year-old male sustains a posterior hip dislocation with an associated femoral head fracture. CT scan confirms the femoral head fracture involves the fovea capitis and extends superiorly to the weight-bearing zone, with an associated posterior wall acetabular fracture. Based on the Pipkin classification, what type of fracture is this?
. Pipkin Type I
. Pipkin Type II
. Pipkin Type III
. Pipkin Type IV
. Pipkin Type V

Correct Answer & Explanation

. Pipkin Type IV


Explanation

Pipkin Type IV is defined as a femoral head fracture (any type) with an associated acetabular fracture. Type I is below the fovea, Type II is above the fovea, and Type III is associated with a femoral neck fracture.

Question 1465

Topic: 2. Trauma

In a subtrochanteric femur fracture, the proximal fragment typically assumes a characteristic position due to unopposed muscle forces. Which combination of muscles is primarily responsible for the flexion, abduction, and external rotation of the proximal fragment?

. Iliopsoas, gluteus medius, and short external rotators
. Adductor longus, gluteus maximus, and rectus femoris
. Hamstrings, tensor fasciae latae, and pectineus
. Iliopsoas, adductor magnus, and vastus lateralis
. Gluteus minimus, gracilis, and semitendinosus

Correct Answer & Explanation

. Iliopsoas, gluteus medius, and short external rotators


Explanation

The proximal fragment in a subtrochanteric fracture is deformed into flexion (iliopsoas), abduction (gluteus medius/minimus), and external rotation (short external rotators). Recognizing these deforming forces is critical for achieving and maintaining proper intraoperative reduction.

Question 1466

Topic: 2. Trauma

A 68-year-old male sustains a reverse obliquity intertrochanteric femur fracture (AO/OTA 31-A3). Biomechanically, why is a cephalomedullary nail preferred over a sliding hip screw (SHS) for this specific fracture pattern?

. It allows for controlled impaction along the fracture line
. It prevents medial displacement of the femoral shaft
. It provides better purchase in the osteoporotic femoral head
. It reduces the risk of heterotopic ossification
. It eliminates the need for distal interlocking screws

Correct Answer & Explanation

. It prevents medial displacement of the femoral shaft


Explanation

In reverse obliquity fractures, the primary fracture line slopes distal-lateral to proximal-medial. A sliding hip screw allows the femoral shaft to excessively displace medially, leading to construct failure; a cephalomedullary nail acts as an intramedullary lateral buttress to prevent this medialization.

Question 1467

Topic: 2. Trauma

A 35-year-old male falls from a roof and sustains a Schatzker VI tibial plateau fracture. On presentation, his leg is tense, and he has extreme pain with passive stretch of the hallux. If compartment syndrome is confirmed and four-compartment fasciotomies are performed, how should the definitive management of the articular fracture ideally be staged?

. Immediate open reduction and internal fixation (ORIF) through the fasciotomy incisions
. Application of a spanning external fixator, followed by ORIF 1-3 weeks later when soft tissues permit
. Primary total knee arthroplasty
. Closed reduction and long leg casting
. Immediate definitive external fixation (Ilizarov) without internal fixation

Correct Answer & Explanation

. Application of a spanning external fixator, followed by ORIF 1-3 weeks later when soft tissues permit


Explanation

High-energy tibial plateau fractures with severe soft tissue compromise or compartment syndrome require damage-control orthopedics. A spanning external fixator stabilizes the fracture, allowing soft tissues to recover and swelling to subside before definitive ORIF is performed 1-3 weeks later.

Question 1468

Topic: 2. Trauma

During a Kocher-Langenbeck approach for a posterior wall acetabular fracture, the surgeon elevates the gluteus minimus off the ilium. To prevent iatrogenic denervation of the abductor musculature, dissection superior to the greater sciatic notch should be limited to what distance?

. 2 cm
. 5 cm
. 8 cm
. 10 cm
. 12 cm

Correct Answer & Explanation

. 5 cm


Explanation

The superior gluteal neurovascular bundle exits the greater sciatic notch and courses between the gluteus medius and minimus. Dissection should be kept strictly within 5 cm of the acetabular rim to avoid injuring this bundle, which would denervate the hip abductors.

Question 1469

Topic: 2. Trauma

A 29-year-old male presents with a displaced femoral neck fracture. To preserve the primary blood supply to the femoral head during surgical exposure, the surgeon must be cautious not to injure the deep branch of the medial femoral circumflex artery (MFCA). Where is this vessel consistently located?

. Anterior to the pectineus muscle
. Between the piriformis and superior gemellus tendons
. Between the pectineus and iliopsoas tendons
. Between the quadratus femoris and the inferior gemellus
. Superior to the gluteus minimus insertion

Correct Answer & Explanation

. Between the quadratus femoris and the inferior gemellus


Explanation

The deep branch of the MFCA provides the main blood supply to the femoral head. It courses posterior to the obturator externus and anterior to the quadratus femoris, typically found in the space between the superior border of the quadratus femoris and the inferior gemellus.

Question 1470

Topic: 2. Trauma

A hemodynamically stable polytrauma patient presents with an ipsilateral closed midshaft femur fracture and a closed midshaft tibia fracture (floating knee). Which of the following describes the most efficient and well-accepted surgical approach for definitive intramedullary nailing of both fractures?

. Antegrade femur nailing and antegrade tibia nailing through separate incisions
. Retrograde femur nailing and antegrade tibia nailing through a single median parapatellar incision
. Plating of the femur and antegrade nailing of the tibia
. External fixation of the femur and intramedullary nailing of the tibia
. Retrograde tibia nailing and antegrade femur nailing

Correct Answer & Explanation

. Retrograde femur nailing and antegrade tibia nailing through a single median parapatellar incision


Explanation

For a 'floating knee' (ipsilateral femur and tibia fractures), a single midline incision with a medial or lateral parapatellar approach allows for retrograde nailing of the femur and antegrade nailing of the tibia efficiently without the need to reposition the patient.

Question 1471

Topic: 2. Trauma
A 72-year-old female presents to the emergency department after a low-energy fall onto her outstretched arm. Radiographs reveal a displaced two-part surgical neck fracture of the proximal humerus with 1.2 cm displacement and 50 degrees of varus angulation. She has a history of well-controlled hypertension and type 2 diabetes. She lives independently, is right-hand dominant, and enjoys gardening and playing cards. On examination, she has intact neurovascular status distally. Based on the provided case information, which of the following is the most appropriate initial management strategy?
. Immediate open reduction and internal fixation (ORIF) with a locking plate.
. Hemiarthroplasty due to age and fracture displacement.
. Reverse total shoulder arthroplasty (RTSA) due to fracture pattern and age.
. Non-operative management with sling immobilization and early pendulum exercises.
. Closed reduction and percutaneous pinning.

Correct Answer & Explanation

. Non-operative management with sling immobilization and early pendulum exercises.


Explanation

The case describes a 72-year-old female with a displaced two-part surgical neck fracture. While the fracture is displaced beyond the typical non-operative criteria (>1 cm displacement, >45 degrees angulation), the text emphasizes that non-operative management is often appropriate for two-part surgical neck fractures in elderly, low-demand patients. The PROXIMAL trial (2015) found no significant difference in outcomes between locking plate fixation and non-operative treatment for displaced proximal humerus fractures in adults, particularly in an older population. Early pendulum exercises are a cornerstone of non-operative rehabilitation to prevent stiffness.

Question 1472

Topic: 2. Trauma

A 35-year-old male sustains a high-energy trauma resulting in a complex proximal humerus fracture. Imaging reveals displacement of the greater tuberosity, lesser tuberosity, and surgical neck fragments relative to the humeral head. The humeral head itself remains in anatomical alignment with the glenoid. According to the Neer classification system, how would this fracture be categorized?

. One-part fracture
. Two-part fracture
. Three-part fracture
. Four-part fracture
. Fracture-dislocation

Correct Answer & Explanation

. Four-part fracture


Explanation

Correct Answer: DThe Neer classification system categorizes PHFs based on the number of displaced 'parts' (humeral head, greater tuberosity, lesser tuberosity, and surgical neck) and displacement criteria (>1 cm displacement or >45 degrees angulation). The question states 'displacement of the greater tuberosity, lesser tuberosity, and surgical neck fragments relative to the humeral head.' This means three segments (greater tuberosity, lesser tuberosity, surgical neck) are displaced relative to the humeral head, which itself is considered the fourth part. Therefore, this is a four-part fracture.A one-part fracture is nondisplaced or minimally displaced.A two-part fracture involves displacement of one major segment relative to the others (e.g., surgical neck, greater tuberosity).A three-part fracture involves displacement of two segments relative to the humeral head.A fracture-dislocation involves any of the above combined with glenohumeral dislocation, which is not described here as the humeral head remains in anatomical alignment with the glenoid.

Question 1473

Topic: 2. Trauma

A 68-year-old male undergoes open reduction and internal fixation with a locking plate for a three-part proximal humerus fracture. Postoperatively, radiographs show good reduction and hardware placement. Six months later, he presents with persistent shoulder pain, limited range of motion, and new radiographs demonstrate collapse of the humeral head into a varus deformity, with several screws having penetrated the articular surface. Which of the following factors is MOST likely to have contributed to this complication?

. Inadequate fixation of the lesser tuberosity.
. Excessive external rotation during early rehabilitation.
. Disruption of the posterior circumflex humeral artery.
. Lack of adequate medial calcar support.
. Premature removal of the sling at 2 weeks post-op.

Correct Answer & Explanation

. Lack of adequate medial calcar support.


Explanation

Correct Answer: DThe scenario describes 'collapse of the humeral head into a varus deformity, with several screws having penetrated the articular surface.' This is a classic presentation of screw cutout and varus collapse. The text explicitly states: 'Loss of medial calcar support significantly increases the risk of screw cutout and construct failure.' It further notes that 'Calcar Screws: Crucial for medial column support. At least one, ideally two, calcar screws should be directed inferiorly and medially towards the calcar region to resist varus collapse.' Therefore, inadequate medial calcar support is the most direct cause of varus collapse and subsequent screw cutout.Inadequate fixation of the lesser tuberosity (A) would primarily lead to internal rotation deformity or subscapularis dysfunction, not typically varus collapse and screw cutout.Excessive external rotation during early rehabilitation (B) could stress tuberosity repairs or lead to dislocation in unstable fractures, but is not the primary mechanism for varus collapse and screw cutout.Disruption of the posterior circumflex humeral artery (C) contributes to avascular necrosis (AVN), which is a different complication, although AVN can eventually lead to collapse. However, the immediate description of varus collapse and screw cutout points more directly to mechanical failure of fixation due to lack of support.Premature removal of the sling at 2 weeks post-op (E) would primarily risk loss of reduction or stress on healing soft tissues, but the fundamental mechanical failure described (varus collapse, screw cutout) is more related to the initial construct stability, particularly medial support.

Question 1474

Topic: 2. Trauma
A 55-year-old female sustains a displaced greater tuberosity fracture of the right shoulder after a fall. Radiographs confirm a >5 mm displacement of the greater tuberosity fragment. She is active, right-hand dominant, and has no significant comorbidities. Which of the following is the most compelling reason for operative intervention in this patient?
. High risk of avascular necrosis of the humeral head.
. Potential for internal rotation contracture.
. Significant risk of subacromial impingement and rotator cuff dysfunction.
. Difficulty achieving union with non-operative management.
. Increased risk of axillary nerve injury with conservative care.

Correct Answer & Explanation

. Significant risk of subacromial impingement and rotator cuff dysfunction.


Explanation

Displaced greater tuberosity fractures with displacement >5 mm, particularly in active patients, carry a high risk of impingement and rotator cuff dysfunction if left unreduced. This can lead to subacromial impingement and weakness, which drives the indication for operative intervention.

Question 1475

Topic: 2. Trauma

A 48-year-old male presents with a displaced two-part surgical neck fracture. He is a highly active individual and desires to return to competitive sports. During pre-operative planning, a CT scan is obtained. Which of the following pieces of information obtained from the CT scan is MOST critical for planning the surgical approach and fixation strategy?

. Assessment of rotator cuff integrity.
. Detailed information on comminution and articular involvement.
. Identification of brachial plexus pathology.
. Confirmation of axillary nerve course.
. Evaluation of pre-existing shoulder arthritis.

Correct Answer & Explanation

. Detailed information on comminution and articular involvement.


Explanation

Correct Answer: BThe text highlights the importance of CT scans: 'Computed Tomography (CT) Scan: Indispensable for complex fractures, particularly three- and four-part fractures, fracture-dislocations, and head-splitting injuries. Provides detailed information on comminution, articular involvement, glenoid impression fractures, and precise tuberosity displacement. 3D reconstructions are invaluable for understanding fracture morphology and planning reduction maneuvers.' For a displaced two-part surgical neck fracture, understanding the extent of comminution and any subtle articular involvement (even if not a primary head-splitting fracture) is crucial for selecting the appropriate plate, screw trajectories, and reduction techniques to restore anatomy and prevent complications like screw cutout or post-traumatic arthritis.Assessment of rotator cuff integrity (A) is more typically done with MRI, though severe tears might be suspected clinically. While important, CT's primary strength for fracture planning is bony detail.Identification of brachial plexus pathology (C) is also better assessed with MRI or clinical neurophysiological studies, not typically the primary role of CT in acute fracture planning.Confirmation of axillary nerve course (D) is generally understood anatomically (5-7 cm distal to acromion) and protected surgically; CT is not typically used to map nerve courses for routine PHF planning.Evaluation of pre-existing shoulder arthritis (E) can be seen on radiographs and CT, but for an acute fracture, the primary focus of the CT is the fracture itself and its implications for fixation, rather than pre-existing arthritis unless it's a major factor influencing arthroplasty decision-making.

Question 1476

Topic: 2. Trauma
A 65-year-old female undergoes ORIF with a locking plate for a three-part proximal humerus fracture. Postoperatively, she is placed in a sling. According to the rehabilitation protocol described, which of the following activities is most appropriate to initiate during Phase I (Immobilization and Early Passive Motion), typically within the first week, assuming fracture stability?
. Active shoulder abduction against gravity.
. Resistive isometric external rotation.
. Gentle pendulum exercises.
. Active-assisted shoulder flexion using a pulley system.
. Weight-bearing on the affected arm.

Correct Answer & Explanation

. Gentle pendulum exercises.


Explanation

Phase I (Immobilization and Early Passive Motion) goals are to protect the surgical repair, minimize pain and swelling, and initiate early passive range of motion (PROM) to prevent stiffness. Pendulum exercises are gentle, gravity-assisted swings of the arm initiated early, often within the first week, based on pain and fracture stability.

Question 1477

Topic: 2. Trauma

A 58-year-old male undergoes ORIF of a complex proximal humerus fracture. During the deltopectoral approach, the surgeon identifies the cephalic vein. According to the described technique, what is the typical management of the cephalic vein?

. It is routinely ligated and divided to maximize exposure.
. It is retracted medially with the pectoralis major.
. It is retracted laterally with the deltoid.
. It is dissected free and transposed to a subcutaneous pocket.
. It is always preserved without retraction to avoid thrombosis.

Correct Answer & Explanation

. It is retracted laterally with the deltoid.


Explanation

Correct Answer: CThe text states, under 'Deltopectoral Groove' dissection: 'The cephalic vein is typically retracted laterally with the deltoid, but can be ligated and divided if necessary for better exposure, particularly in revision cases or when space is limited. Care should be taken to preserve smaller venous tributaries.'Option A is incorrect because it is not routinely ligated and divided, but rather 'if necessary.'Option B is incorrect; it is retracted laterally with the deltoid, not medially with the pectoralis major.Option D is incorrect; there is no mention of dissecting it free and transposing it.Option E is incorrect; while preservation is preferred, it is often retracted, and can be ligated if necessary, so 'always preserved without retraction' is too absolute.

Question 1478

Topic: 2. Trauma
A 70-year-old female with a displaced three-part proximal humerus fracture is undergoing ORIF with a locking plate. The surgeon is about to insert screws into the humeral head. Based on the biomechanical principles and surgical technique described, which type of screw is considered crucial for resisting varus collapse and providing critical support for internal fixation?
. Cortical screws in the greater tuberosity.
. Lag screws across the anatomical neck.
. Calcar screws directed inferiorly and medially.
. Screws placed through the bicipital groove.
. Screws directed superiorly into the acromion.

Correct Answer & Explanation

. Calcar screws directed inferiorly and medially.


Explanation

The medial calcar is a dense trabecular bone region that acts as a crucial weight-bearing structure, resisting varus collapse and providing critical support for internal fixation. Calcar screws, directed inferiorly and medially towards the calcar region, are crucial for medial column support to prevent screw cutout and construct failure.

Question 1479

Topic: 2. Trauma

During the femoral preparation phase of a primary THA, the surgeon is broaching the femoral canal. The patient's femur is noted to have a narrow canal with very thick cortical bone, consistent with a Dorr Type A morphology. The surgeon is attempting to achieve a stable metaphyseal press-fit for an uncemented stem.

In this scenario, which intraoperative complication is the surgeon at the highest risk for during forceful broaching and subsequent stem impaction?

. Sciatic nerve injury.
. Acetabular medial wall perforation.
. Intraoperative femoral fracture.
. External iliac artery injury.
. Excessive leg lengthening.

Correct Answer & Explanation

. Intraoperative femoral fracture.


Explanation

Correct Answer: CA Dorr Type A femur, characterized by a narrow canal and very thick cortical bone (often described as a 'champagne flute' shape), is particularly susceptible to intraoperative femoral fracture during broaching or stem impaction, especially when attempting to achieve a press-fit with an uncemented stem. The rigid, thick cortex offers little elasticity, and forceful impaction can lead to a crack or fracture. Sciatic nerve injury (A) is a risk with excessive leg lengthening or aggressive posterior retraction, but not directly from broaching in a Dorr A femur. Acetabular medial wall perforation (B) and external iliac artery injury (D) are risks associated with acetabular reaming or screw placement, not femoral preparation. Excessive leg lengthening (E) is a concern during trial reduction and final component selection, not typically a direct result of broaching itself, though an undersized stem in a large canal could contribute to instability requiring lengthening.

Question 1480

Topic: 2. Trauma

A 45-year-old male presents after a high-energy motor vehicle collision. Imaging reveals a complex acetabular fracture involving the anterior superior iliac spine (ASIS), extending through the iliopectineal line, and involving the superior pubic ramus. Based on the Judet and Letournel classification system and the provided anatomical understanding:

. Posterior column
. Posterior wall
. Anterior column
. Transverse fracture
. Both column fracture

Correct Answer & Explanation

. Anterior column


Explanation

Correct Answer: CThe correct answer is theAnterior column. The case explicitly states that the fracture involves the anterior superior iliac spine (ASIS), extends through the iliopectineal line, and involves the superior pubic ramus. According to the 'Surgical Anatomy & Biomechanics' section, the anterior column is defined as extending from the ASIS through the iliopectineal line, crossing the anterior acetabulum to the superior pubic ramus. It also includes the anterior half of the acetabular roof. This description perfectly matches the fracture pattern described in the vignette. The posterior column, posterior wall, transverse, and both column fractures involve different anatomical structures and fracture lines as detailed in the Judet and Letournel classification.