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Question 5801

Topic: Total Hip Arthroplasty (THA)

To preserve the primary blood supply to the femoral head during a posterior approach to the hip, the surgeon must be careful not to injure the medial femoral circumflex artery (MFCA). The main deep branch of the MFCA typically runs between which two muscles?

. Piriformis and superior gemellus
. Obturator internus and inferior gemellus
. Quadratus femoris and obturator externus
. Gluteus medius and minimus
. Pectineus and adductor longus

Correct Answer & Explanation

. Quadratus femoris and obturator externus


Explanation

The deep branch of the medial femoral circumflex artery (MFCA) provides the predominant blood supply to the adult femoral head. It courses anatomically posterior to the obturator externus and anterior to the quadratus femoris. Leaving the obturator externus intact and carefully managing the quadratus femoris protects this vital vessel.

Question 5802

Topic: 3. Adult Reconstruction (Hip & Knee)

A 32-year-old male sustains a high-energy posterior hip dislocation. After successful closed reduction, a post-reduction CT scan shows a small, non-displaced articular impaction of the femoral head. What is the most appropriate management?

. Immediate weight-bearing as tolerated.
. Skeletal traction for 4-6 weeks.
. Strict non-weight-bearing for 6-8 weeks with protected range of motion.
. Open reduction and internal fixation of the femoral head lesion.
. Total hip arthroplasty.

Correct Answer & Explanation

. Strict non-weight-bearing for 6-8 weeks with protected range of motion.


Explanation

Following a posterior hip dislocation, even small articular impaction fractures of the femoral head (Pipkin type I or II) should be managed with strict non-weight-bearing for 6-8 weeks, combined with protected range of motion (C) to prevent further damage to the articular cartilage and allow for healing. Weight-bearing (A) or skeletal traction (B) are inappropriate. Open reduction (D) is typically reserved for larger, displaced Pipkin fractures or incarcerated fragments. Total hip arthroplasty (E) is a salvage procedure for established post-traumatic arthritis or severe femoral head damage.

Question 5803

Topic: 3. Adult Reconstruction (Hip & Knee)

A 78-year-old female falls and sustains a comminuted distal femur fracture immediately above her well-fixed total knee arthroplasty (TKA). The TKA components are stable. According to the Vancouver classification, this would most likely be a:

. Type A fracture
. Type B1 fracture
. Type B2 fracture
. Type B3 fracture
. Type C fracture

Correct Answer & Explanation

. Type B1 fracture


Explanation

The Vancouver classification for periprosthetic fractures around a TKA categorizes fractures based on location and implant stability. Type A fractures are metaphyseal, Type B are diaphyseal, and Type C are distal to the implant. Type B fractures are further subdivided by implant stability: B1 (implant stable), B2 (implant loose but good bone stock), and B3 (implant loose with poor bone stock). A comminuted distal femur fracture immediately above awell-fixedTKA is a diaphyseal fracture with a stable implant, fitting the description of a Type B1 fracture.

Question 5804

Topic: 3. Adult Reconstruction (Hip & Knee)

A 28-year-old male sustains a posterior hip dislocation in a motor vehicle accident. He presents to the ED 4 hours after the injury. What is the most critical management principle regarding the timing of reduction?

. Delay reduction until an MRI can assess soft tissue injury.
. Attempt closed reduction as soon as possible, ideally within 6 hours.
. Perform open reduction immediately to visualize the labrum.
. Administer muscle relaxants and observe for spontaneous reduction.
. Reduce only after an orthopedic surgeon is available for definitive fixation.

Correct Answer & Explanation

. Attempt closed reduction as soon as possible, ideally within 6 hours.


Explanation

Posterior hip dislocations are orthopedic emergencies. The most critical management principle is emergent reduction, ideally within 6 hours, to minimize the risk of avascular necrosis (AVN) of the femoral head. Delaying reduction beyond this timeframe significantly increases the risk of AVN. While MRI is useful for assessing associated injuries, it should not delay emergent closed reduction. Open reduction is indicated if closed reduction fails or for specific associated injuries (e.g., incarcerated fragments), but not as a primary first step. Observation for spontaneous reduction is inappropriate for a true dislocation.

Question 5805

Topic: 3. Adult Reconstruction (Hip & Knee)

A 72-year-old female with a previous total hip arthroplasty (THA) for osteoarthritis falls and sustains a periprosthetic femur fracture. Radiographs show the fracture around the stem, with the stem itself appearing loose (Vancouver Type B3). What is the most appropriate management strategy?

. Open reduction and internal fixation (ORIF) with plates and screws.
. Revision total hip arthroplasty with a longer, often proximally coated, stem.
. Non-operative management with cast immobilization.
. Cerclage wiring around the existing stem.
. Explantation of the prosthesis and Girdlestone resection arthroplasty.

Correct Answer & Explanation

. Revision total hip arthroplasty with a longer, often proximally coated, stem.


Explanation

Vancouver B3 periprosthetic femur fractures are characterized by a fracture around or distal to the stem with a loose femoral stem or significant bone loss. Given the stem looseness, simply fixing the fracture around the existing stem (ORIF with plates/screws or cerclage wires) is insufficient. The unstable stem needs to be addressed. The definitive management is typically revision total hip arthroplasty with a longer, often proximally coated or extensively coated, stem that bypasses the fracture by at least two cortical diameters, sometimes combined with allograft struts or plates for bone grafting and stabilization. Non-operative management is reserved for very stable, non-displaced fractures. Girdlestone is a salvage procedure typically reserved for intractable infection or failed revisions in very low-demand patients.

Question 5806

Topic: 3. Adult Reconstruction (Hip & Knee)
A 70-year-old female sustains a ground-level fall, resulting in an undisplaced femoral neck fracture (Garden Type I). She is otherwise healthy and active. What is the most appropriate surgical management for this fracture?
. Hemiarthroplasty.
. Total hip arthroplasty (THA).
. Cannulated screw fixation (percutaneous pinning).
. Skeletal traction.
. Non-operative management with bed rest.

Correct Answer & Explanation

. Cannulated screw fixation (percutaneous pinning).


Explanation

For an undisplaced (Garden Type I or II) femoral neck fracture in an active, healthy elderly patient, the preferred treatment is usually cannulated screw fixation (percutaneous pinning). This preserves the femoral head, minimizes surgical invasiveness, and aims to achieve fracture union. The risk of avascular necrosis and nonunion is lower than in displaced fractures. Hemiarthroplasty or total hip arthroplasty are typically reserved for displaced femoral neck fractures (Garden Type III or IV) or for patients with pre-existing severe hip arthritis. Skeletal traction and bed rest are outdated and associated with high morbidity/mortality in the elderly.

Question 5807

Topic: 3. Adult Reconstruction (Hip & Knee)

A 45-year-old male presents with a transverse acetabular fracture following a fall. A CT scan confirms a transverse pattern involving both columns. The hip is concentrically reduced, and there is no significant displacement or intra-articular incongruity. Which of the following is the most appropriate management strategy?

. Immediate open reduction and internal fixation (ORIF)
. Skeletal traction followed by delayed ORIF
. Non-operative management with protected weight-bearing
. Total hip arthroplasty (THA)
. Periacetabular osteotomy

Correct Answer & Explanation

. Non-operative management with protected weight-bearing


Explanation

Non-operative management is indicated for acetabular fractures with minimal displacement (<2mm), no intra-articular fragments, and a stable, concentrically reduced hip. Transverse fractures, if undisplaced, can often be managed non-operatively with protected weight-bearing (typically non-weight-bearing for 8-12 weeks). ORIF is reserved for displaced fractures, joint incongruity, or instability. Skeletal traction may be used for highly comminuted or displaced fractures awaiting surgery, but not for stable, undisplaced injuries. THA is a salvage procedure for severe post-traumatic arthritis. Periacetabular osteotomy is for hip dysplasia.

Question 5808

Topic: 3. Adult Reconstruction (Hip & Knee)
A 68-year-old female sustains a low-energy displaced femoral neck fracture (Garden Type III) after a fall at home. She is otherwise healthy and active. What is the most appropriate definitive surgical management?
. Cannulated screw fixation
. Hemiarthroplasty (bipolar or unipolar)
. Total hip arthroplasty (THA)
. Dynamic hip screw (DHS)
. Non-operative management with bed rest

Correct Answer & Explanation

. Total hip arthroplasty (THA)


Explanation

For active, healthy elderly patients with displaced femoral neck fractures (Garden III/IV), total hip arthroplasty (THA) generally yields better functional outcomes, lower reoperation rates, and less pain compared to hemiarthroplasty, especially for those with pre-existing arthritis or high functional demands. While hemiarthroplasty is a viable option, THA is increasingly preferred in this population. Cannulated screw fixation is primarily for non-displaced or minimally displaced fractures (Garden I/II) in younger patients. DHS is not typically used for femoral neck fractures. Non-operative management is associated with high mortality and morbidity in this patient group.

Question 5809

Topic: 3. Adult Reconstruction (Hip & Knee)

What is the primary goal of surgical management for a Garden Type I femoral neck fracture in a young, active adult (under 50 years old)?

. Avoid total hip arthroplasty (THA)
. Preserve femoral head viability and achieve stable anatomical reduction
. Facilitate early weight-bearing
. Minimize operative time
. Reduce risk of deep vein thrombosis

Correct Answer & Explanation

. Preserve femoral head viability and achieve stable anatomical reduction


Explanation

For femoral neck fractures in young, active adults, the paramount goal is to preserve the femoral head and achieve stable anatomical reduction. This is crucial to minimize the risks of avascular necrosis (AVN) and nonunion, which can lead to early degenerative changes and the need for salvage procedures like THA. While avoiding THA is a long-term aim, it's a consequence of successful head preservation. Early weight-bearing is secondary, and minimizing operative time is a general surgical principle, not the primary goal for this specific injury.

Question 5810

Topic: 3. Adult Reconstruction (Hip & Knee)

A 55-year-old female sustains a comminuted intra-articular fracture of the distal femur (AO/OTA 33-C3). What is the primary goal of surgical treatment for this specific fracture?

. Achieve absolute stability and early weight-bearing
. Restore articular congruity and stable fixation to allow early range of motion
. Avoid open reduction to preserve soft tissues
. Minimize operative time at all costs
. Perform a total knee arthroplasty if possible

Correct Answer & Explanation

. Restore articular congruity and stable fixation to allow early range of motion


Explanation

For comminuted intra-articular distal femur fractures (33-C3), the primary surgical goal is to restore articular congruity (anatomical reduction of the joint surface) and achieve stable internal fixation. This allows for early, protected range of motion, which is crucial for preventing stiffness and preserving joint function, while minimizing the risk of post-traumatic arthritis. Absolute stability and immediate full weight-bearing are often not achievable or desirable in the initial phase. Avoiding open reduction is not always possible or advisable. THA is a salvage procedure.

Question 5811

Topic: 3. Adult Reconstruction (Hip & Knee)

Which of the following is considered a relative contraindication for total elbow arthroplasty (TEA) in the setting of primary osteoarthritis?

. Age greater than 70 years
. Low functional demand
. Active infection
. Non-compliance with rehabilitation protocols
. Manual laborer requiring heavy lifting

Correct Answer & Explanation

. Manual laborer requiring heavy lifting


Explanation

Active infection is an absolute contraindication for any joint replacement. Age greater than 70 years and low functional demand are generally considered favorable factors for TEA due to reduced stress on the implant. Non-compliance with rehabilitation protocols is a significant concern as it can compromise the functional outcome and increase the risk of complications, but it's often considered a relative rather than absolute contraindication depending on patient education and support. However, a manual laborer requiring heavy lifting is a strong relative contraindication for TEA, as the prosthesis is not designed to withstand high-impact or high-load activities. Implants have weight-bearing restrictions (typically 5-10 lbs intermittently and 1 lb repetitively), and such activity significantly increases the risk of aseptic loosening, component failure, and periprosthetic fracture. Therefore, a high-demand manual laborer would likely be steered towards alternative surgical options or a highly modified lifestyle post-operatively, making it a more substantial contraindication than non-compliance, which can often be managed with education and support.

Question 5812

Topic: 3. Adult Reconstruction (Hip & Knee)

A 48-year-old construction worker presents with chronic elbow pain and stiffness. His radiographs show advanced tricompartmental osteoarthritis. He reports his job requires heavy lifting, often exceeding 50 lbs. He has failed extensive non-operative management. What is the most appropriate surgical recommendation for this patient?

. Total elbow arthroplasty
. Arthroscopic debridement and loose body removal
. Open debridement and osteophyte excision with ulnar nerve transposition
. Interposition arthroplasty with an autograft or allograft
. Elbow arthrodesis

Correct Answer & Explanation

. Interposition arthroplasty with an autograft or allograft


Explanation

This patient presents with advanced tricompartmental OA and a high-demand occupation requiring heavy lifting. Total elbow arthroplasty (TEA) is generally contraindicated in individuals with high-demand jobs due to the high risk of implant loosening and failure. Arthroscopic or open debridement would likely be insufficient for advanced tricompartmental disease, as it primarily addresses impingement and loose bodies rather than diffuse cartilage loss. Elbow arthrodesis (fusion) results in a complete loss of motion and is a salvage procedure typically reserved for end-stage infection or debilitating pain in patients who cannot undergo or have failed arthroplasty and for whom stability is paramount. Interposition arthroplasty, using either autograft (e.g., fascia lata) or allograft, is a viable option for younger, high-demand patients with advanced arthritis who are not candidates for TEA. It aims to preserve motion and reduce pain by resurfacing the joint without the implant limitations of TEA, making it the most appropriate choice in this scenario.

Question 5813

Topic: 3. Adult Reconstruction (Hip & Knee)

Following a total elbow arthroplasty for severe osteoarthritis, a 68-year-old patient develops a sudden onset of excruciating pain, swelling, and redness around the elbow, associated with fever and chills, 3 weeks post-operatively. Fluid aspirated from the joint shows a white blood cell count of 85,000 cells/µL with 95% neutrophils and positive Gram stain for Staphylococcus aureus. What is the most appropriate management for this acute periprosthetic joint infection?

. Long-term suppressive oral antibiotics
. Debridement, antibiotics, and implant retention (DAIR) with polyethylene exchange if applicable
. Implant removal and immediate reimplantation with new components
. Excisional arthroplasty (girdlestone elbow)
. Continuous passive motion (CPM) with intravenous antibiotics

Correct Answer & Explanation

. Debridement, antibiotics, and implant retention (DAIR) with polyethylene exchange if applicable


Explanation

This patient presents with an acute periprosthetic joint infection (PJI) within 3 weeks of TEA, confirmed by systemic signs, local symptoms, and aspirate analysis. For acute PJI following total joint arthroplasty, especially within the first few weeks or months, debridement, antibiotics, and implant retention (DAIR) is often the preferred strategy, provided the implant is stable, soft tissue coverage is adequate, and the organism is sensitive to antibiotics. In elbow arthroplasty, this would typically involve thorough irrigation and debridement of the joint, exchange of any modular components (e.g., polyethylene bushings in some designs), and a prolonged course of intravenous antibiotics. Long-term suppressive oral antibiotics alone are insufficient for an acute infection with signs of systemic involvement. Immediate reimplantation is typically done after a period of antibiotics following initial removal in a two-stage exchange. Excisional arthroplasty (Girdlestone elbow) is a salvage procedure for chronic or intractable infections. CPM is a rehabilitation modality and not a treatment for infection.

Question 5814

Topic: 3. Adult Reconstruction (Hip & Knee)

Which factor is most strongly associated with an increased risk of revision surgery following total elbow arthroplasty for osteoarthritis?

. Older patient age
. Female gender
. Post-traumatic etiology for OA
. Unlinked implant design
. Low body mass index (BMI)

Correct Answer & Explanation

. Post-traumatic etiology for OA


Explanation

While all options except for 'low BMI' might theoretically have some correlation, post-traumatic etiology for elbow osteoarthritis is consistently associated with a higher rate of complications and revision surgery following TEA. This is often due to poorer bone quality, previous surgeries, greater soft tissue scarring, and compromised ligamentous structures, which make primary TEA more challenging and increase the risk of infection, aseptic loosening, and instability compared to TEA for primary inflammatory or primary degenerative OA. Older age and female gender are not consistently linked to higher revision rates and may even be associated with lower demand, which is beneficial for TEA longevity. Unlinked implants, while requiring good ligamentous integrity, are not inherently associated with a higher revision rate than linked implants when selected appropriately for the right patient.

Question 5815

Topic: 3. Adult Reconstruction (Hip & Knee)

What is the most common mode of failure for a total elbow arthroplasty implanted for osteoarthritis?

. Periprosthetic fracture
. Ulnar nerve palsy
. Aseptic loosening
. Deep infection
. Triceps insufficiency

Correct Answer & Explanation

. Aseptic loosening


Explanation

Aseptic loosening is generally considered the most common long-term mode of failure for total elbow arthroplasty, regardless of the indication (RA or OA). The elbow is subjected to complex forces, and the bone-cement interface or bone-implant interface can eventually fail. While periprosthetic fracture, ulnar nerve palsy (often secondary to scar or impingement), deep infection, and triceps insufficiency are known complications, aseptic loosening has a higher incidence over the lifetime of the implant, particularly in more active patients or those with poor bone quality.

Question 5816

Topic: 3. Adult Reconstruction (Hip & Knee)

Which of the following statements regarding distraction arthroplasty for end-stage elbow osteoarthritis is most accurate?

. It is contraindicated in patients with significant joint instability.
. The primary mechanism of action is stimulation of hyaline cartilage regeneration.
. It requires prolonged external fixation, which carries a risk of pin tract infection.
. It is a definitive treatment for pain relief with full restoration of range of motion.
. It is preferred over total elbow arthroplasty for low-demand, elderly patients.

Correct Answer & Explanation

. It requires prolonged external fixation, which carries a risk of pin tract infection.


Explanation

Distraction arthroplasty involves the application of an external fixator to distract the joint surfaces, aiming to unload the joint and promote the formation of fibrocartilaginous repair tissue. It does require prolonged external fixation (typically 6-12 weeks or more), and pin tract infection is a common and significant complication. While it can improve pain and some motion, it does not typically achieve full restoration of range of motion or true hyaline cartilage regeneration. It can be used for patients with significant instability, provided the fixator is appropriately designed. It is generally considered a salvage procedure for younger, higher-demand patients who are not suitable for TEA, or for infected arthroplasties, rather than being preferred for low-demand elderly patients who are often better candidates for TEA.

Question 5817

Topic: 3. Adult Reconstruction (Hip & Knee)

Which condition is a major contraindication for any form of elbow arthroplasty (interposition or total)?

. Advanced age (over 75)
. Significant obesity
. Active systemic inflammatory arthritis (e.g., rheumatoid arthritis)
. Prior elbow infection with ongoing signs of inflammation
. Chronic ulnar nerve neuropathy

Correct Answer & Explanation

. Prior elbow infection with ongoing signs of inflammation


Explanation

Prior elbow infection with ongoing signs of inflammation or active infection is an absolute contraindication for any joint replacement or interposition arthroplasty due to the high risk of recurrent infection and catastrophic failure of the implant. Advanced age, significant obesity, and chronic ulnar nerve neuropathy are not absolute contraindications, though they can increase surgical risk or complicate outcomes. Active systemic inflammatory arthritis (like rheumatoid arthritis) is actually a common indication for elbow arthroplasty, not a contraindication, although specific surgical considerations are often needed due to bone quality and soft tissue involvement.

Question 5818

Topic: 3. Adult Reconstruction (Hip & Knee)

A 68-year-old female presents with severe end-stage elbow osteoarthritis. She has a history of a chronic, low-grade infection in the elbow that was treated with long-term antibiotics 2 years ago, with no current signs of active infection. However, cultures from the previous surgery were positive for a multi-drug resistant organism. She desires pain relief and improved function. What is the most appropriate recommendation?

. Proceed with a one-stage total elbow arthroplasty with extended antibiotic prophylaxis.
. Perform a two-stage total elbow arthroplasty protocol.
. Consider a distraction arthroplasty as a definitive solution.
. Recommend permanent excisional arthroplasty (Girdlestone elbow).
. Initiate a new course of empiric antibiotics before any surgical intervention.

Correct Answer & Explanation

. Perform a two-stage total elbow arthroplasty protocol.


Explanation

A history of prior infection, especially with resistant organisms, is a critical concern for total joint arthroplasty. Even if no active infection is evident, the risk of recurrence is significant. Therefore, a two-stage total elbow arthroplasty protocol is the most appropriate and safest approach. This involves implant removal (if present) or extensive debridement, placement of an antibiotic-loaded cement spacer, and a prolonged course of culture-specific antibiotics. After a period of quiescence (typically several months) and normalization of infection markers (ESR, CRP) and negative aspirations, a second stage of definitive TEA is performed. One-stage TEA is too risky given the history. Distraction arthroplasty or excisional arthroplasty are salvage procedures for active or intractable infection, not primary solutions for chronic quiescent infection where reconstruction is desired. Empiric antibiotics alone without surgical debridement are insufficient for recurrent infection in this context.

Question 5819

Topic: 3. Adult Reconstruction (Hip & Knee)

What is the typical load-bearing capacity restriction advised for a patient after total elbow arthroplasty?

. No lifting restrictions after 6 months
. Repetitive lifting limited to 10 lbs, single lift to 25 lbs
. Repetitive lifting limited to 1 lb, single lift to 5 lbs
. Unlimited lifting once pain-free
. Only sedentary activities permitted indefinitely

Correct Answer & Explanation

. Repetitive lifting limited to 1 lb, single lift to 5 lbs


Explanation

Total elbow arthroplasty implants, particularly linked or semiconstrained designs, have strict weight-bearing restrictions to prevent aseptic loosening and implant failure. The general recommendation is repetitive lifting limited to 1 lb and single lifts limited to 5-10 lbs, indefinitely. Exceeding these limits significantly increases the risk of complications. There are no scenarios where unrestricted lifting is advised. While sedentary activities are often promoted, patients can engage in light activities of daily living within these weight restrictions.

Question 5820

Topic: 3. Adult Reconstruction (Hip & Knee)

Which of the following describes the role of a 'semiconstrained' total elbow arthroplasty implant?

. It provides complete stability, acting as a true hinge, independent of soft tissues.
. It relies entirely on intact collateral ligaments for stability.
. It allows limited rotation between the humeral and ulnar components, balancing stability and stress transfer.
. It is a resurfacing implant that preserves native bone geometry.
. It is only used in revision cases where severe bone loss is present.

Correct Answer & Explanation

. It allows limited rotation between the humeral and ulnar components, balancing stability and stress transfer.


Explanation

Semiconstrained total elbow arthroplasty implants, the most common type used in OA and RA, allow for a small amount of rotational and varus/valgus movement at the hinge mechanism between the humeral and ulnar components. This design characteristic is crucial because it helps to reduce stress at the bone-cement or bone-implant interface, thereby reducing the risk of aseptic loosening, while still providing significant inherent stability that is often lacking in patients with severe arthritis and compromised collateral ligaments. Fully constrained implants act as a true hinge with no play but transfer high stresses to the bone, leading to higher rates of loosening. Unlinked implants rely entirely on intact collateral ligaments for stability. Resurfacing implants are distinct. Semiconstrained implants are used in primary and revision cases.