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3. Adult Reconstruction (Hip & Knee) MCQs

Practice Set 21 of 326

This practice set contains high-yield board review questions covering key concepts in 3. Adult Reconstruction (Hip & Knee). Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 401

Topic: 3. Adult Reconstruction (Hip & Knee)

A 70-year-old female is post-operative day 2 from a total knee arthroplasty. She is completely asymptomatic, ambulating well, and hemodynamically stable. Her hemoglobin has dropped from 11.2 g/dL preoperatively to 7.5 g/dL today. What is the most appropriate management?

. Transfuse 1 unit of packed red blood cells
. Transfuse 2 units of packed red blood cells
. Administer intravenous iron sucrose
. Observation and continue physical therapy
. Administer subcutaneous erythropoietin

Correct Answer & Explanation

. Observation and continue physical therapy

Explanation

For hemodynamically stable, asymptomatic postoperative patients, a restrictive transfusion strategy with a hemoglobin threshold of less than 7.0 g/dL is recommended. Since she is asymptomatic with a hemoglobin of 7.5 g/dL, observation is the most appropriate step.

Question 402

Topic: 3. Adult Reconstruction (Hip & Knee)

A 65-year-old male presents with increasing pain and stiffness 6 months after a reverse total shoulder arthroplasty. Inflammatory markers are mildly elevated, and joint aspiration yields cloudy fluid. What is the most likely causative organism?

. Staphylococcus aureus
. Pseudomonas aeruginosa
. Cutibacterium acnes
. Streptococcus pyogenes
. Enterococcus faecalis

Correct Answer & Explanation

. Cutibacterium acnes

Explanation

Cutibacterium acnes is a slow-growing, anaerobic Gram-positive bacillus that is part of the normal skin flora, heavily concentrated around the shoulder. It is the most common organism responsible for indolent, chronic periprosthetic joint infections following shoulder arthroplasty.

Question 403

Topic: 3. Adult Reconstruction (Hip & Knee)

A 68-year-old female with poorly controlled type 2 diabetes mellitus is evaluated for an elective total knee arthroplasty. What is the maximum recommended target HbA1c level prior to elective joint surgery to minimize the risk of complications?

. Less than 6.0%
. Less than 7.0%
. Less than 8.0%
. Less than 9.0%
. Less than 10.0%

Correct Answer & Explanation

. Less than 8.0%

Explanation

The AAOS and other major surgical guidelines recommend optimizing diabetic patients by achieving an HbA1c of less than 8.0% prior to elective total joint arthroplasty. Levels above 8.0% are associated with significantly increased risks of surgical site infection and poor wound healing.

Question 404

Topic: 3. Adult Reconstruction (Hip & Knee)
A 25-year-old male sustains a vertically oriented (Pauwels type III) femoral neck fracture after a fall from a height. Which fixation construct provides the greatest biomechanical stability for this specific fracture pattern?
. Three parallel cancellous cannulated screws
. Sliding hip screw with a derotational screw
. Cephalomedullary nail
. Bipolar hemiarthroplasty
. Total hip arthroplasty

Correct Answer & Explanation

. Sliding hip screw with a derotational screw

Explanation

Pauwels III femoral neck fractures have a high degree of verticality, subjecting them to extreme shear forces. A fixed-angle device, such as a sliding hip screw, provides superior biomechanical stability compared to parallel screws by converting shear forces into compressive forces.

Question 405

Topic: 3. Adult Reconstruction (Hip & Knee)

A 65-year-old female presents with groin pain 5 years after receiving a metal-on-metal total hip arthroplasty. MRI reveals a large cystic fluid collection adjacent to the joint. If a biopsy of the periprosthetic tissue is performed, what is the most likely histologic finding?

. Sheets of acute neutrophils
. Birefringent polymeric wear debris under polarized light
. Diffuse perivascular lymphocytic infiltrate
. Granulomas with extensive caseating necrosis
. Malignant spindle cells with high mitotic index

Correct Answer & Explanation

. Diffuse perivascular lymphocytic infiltrate

Explanation

Metal-on-metal articulations can cause an aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL), also known as a pseudotumor. Histology typically demonstrates a diffuse perivascular lymphocytic infiltrate due to a Type IV delayed hypersensitivity reaction.

Question 406

Topic: 3. Adult Reconstruction (Hip & Knee)

A 68-year-old male presents with persistent pain and swelling 1 year after a primary total knee arthroplasty. Serologic inflammatory markers (ESR and CRP) are significantly elevated. A joint aspiration is performed. Which of the following synovial fluid profiles is highly diagnostic of a chronic periprosthetic joint infection?

. WBC 1,500 cells/mcL with 50% PMNs
. WBC 2,500 cells/mcL with 60% PMNs
. WBC 4,500 cells/mcL with 85% PMNs
. WBC 80,000 cells/mcL with 95% PMNs and negatively birefringent crystals
. WBC 500 cells/mcL with 20% PMNs

Correct Answer & Explanation

. WBC 4,500 cells/mcL with 85% PMNs

Explanation

In the setting of a chronic periprosthetic joint infection (PJI) of the knee, a synovial fluid WBC count greater than 3,000 cells/mcL or a PMN percentage greater than 80% is considered diagnostic.

Question 407

Topic: 3. Adult Reconstruction (Hip & Knee)

A surgeon is performing a primary total hip arthroplasty utilizing a posterior approach. To optimize hip stability and minimize the risk of posterior dislocation, the acetabular component should be placed within Lewinnek's safe zone. What are the specific target ranges for this zone?

. 15 +/- 10 degrees of anteversion and 40 +/- 10 degrees of inclination (abduction)
. 0 degrees of anteversion and 30 degrees of inclination (abduction)
. 30 +/- 10 degrees of anteversion and 55 +/- 10 degrees of inclination (abduction)
. 15 +/- 10 degrees of retroversion and 40 +/- 10 degrees of inclination (abduction)
. 5 +/- 5 degrees of anteversion and 25 +/- 5 degrees of inclination (abduction)

Correct Answer & Explanation

. 15 +/- 10 degrees of anteversion and 40 +/- 10 degrees of inclination (abduction)

Explanation

Lewinnek defined the radiographic "safe zone" for acetabular cup placement to minimize dislocation risk. The traditional, widely accepted target is 15 +/- 10 degrees of anteversion and 40 +/- 10 degrees of inclination.

Question 408

Topic: 3. Adult Reconstruction (Hip & Knee)

A 35-year-old male sustains a displaced femoral neck fracture in a high-speed motor vehicle accident. He is hemodynamically stable. What does current literature indicate regarding the timing of surgical fixation for this injury?

. Fixation must occur within 6 hours to significantly reduce the risk of avascular necrosis (AVN).
. Fixation within 24 hours has comparable rates of AVN and nonunion to fixation within 6 hours.
. Urgent hemiarthroplasty is the preferred treatment to avoid AVN entirely.
. Delayed fixation beyond 48 hours is optimal to allow for complete soft tissue optimization.
. Primary total hip arthroplasty (THA) is the gold standard regardless of timing.

Correct Answer & Explanation

. Fixation within 24 hours has comparable rates of AVN and nonunion to fixation within 6 hours.

Explanation

Current orthopedic literature demonstrates no significant difference in the rates of osteonecrosis or nonunion when fixing displaced femoral neck fractures in young adults within 24 hours compared to less than 6 hours.

Question 409

Topic: 3. Adult Reconstruction (Hip & Knee)

A 55-year-old male undergoes a total hip arthroplasty using a ceramic-on-ceramic bearing surface. While this bearing choice provides extremely low wear rates, which of the following complications is most uniquely associated with this specific coupling?

. Trunnionosis
. Massive pelvic osteolysis
. Squeaking
. Polyethylene creep
. Metallosis

Correct Answer & Explanation

. Squeaking

Explanation

Ceramic-on-ceramic bearings exhibit excellent wear characteristics but carry unique risks, including the phenomenon of audible 'squeaking' and the potential for catastrophic ceramic fracture.

Question 410

Topic: 3. Adult Reconstruction (Hip & Knee)

A 78-year-old community-dwelling female with severe rheumatoid arthritis and osteoporosis sustains a highly comminuted, intra-articular distal humerus fracture (AO/OTA 13-C3). Which of the following is an established advantage of primary total elbow arthroplasty (TEA) over open reduction and internal fixation (ORIF) in this specific patient?

. Decreased lifetime risk of implant loosening or failure
. Ability to return to heavy manual labor or lifting >10 lbs
. Lower rates of postoperative ulnar neuropathy
. More reliable and rapid restoration of functional range of motion
. Decreased incidence of deep infection

Correct Answer & Explanation

. More reliable and rapid restoration of functional range of motion

Explanation

In elderly patients with severe osteopenia, comminution, or pre-existing joint disease, TEA provides a more reliable and rapid return to functional range of motion compared to ORIF. However, TEA requires strict lifetime lifting restrictions to prevent aseptic loosening.

Question 411

Topic: 3. Adult Reconstruction (Hip & Knee)

Overtightening a screw during fracture fixation, particularly in diaphyseal bone, can lead to which of the following complications?

. Increased bone-screw interface strength due to enhanced compression.
. Reduction in stress shielding effects on the bone.
. Bone necrosis around the screw due to excessive pressure and heat.
. Improved blood supply to the fracture site from increased stability.
. Premature degradation of bioabsorbable implants.

Correct Answer & Explanation

. Bone necrosis around the screw due to excessive pressure and heat.

Explanation

Correct Answer: COvertightening a screw generates excessive torque, which can lead to several problems: 1) Stripping the bone threads, resulting in loss of purchase. 2) Creation of microfractures in the bone around the screw, weakening its fixation. 3) Generation of heat and excessive localized pressure leading to pressure necrosis of the bone around the screw, which can then lead to aseptic loosening or even infection if bacteria gain access. While initial compression is desired (Option A), overtightening goes beyond the elastic limits of the bone. Stress shielding (Option B) is unrelated. Blood supply (Option D) is not improved, and excessive pressure can compromise it. Premature degradation (Option E) of bioabsorbable implants is not a direct consequence of overtightening itself, but rather related to their material properties and environment.

Question 412

Topic: Total Knee Arthroplasty (TKA)
A 4-year-old female with Langenskiรถld Stage III infantile Blount disease requires a proximal tibial osteotomy. To fully address the typical three-dimensional deformity associated with this condition, the osteotomy must correct varus, as well as which of the following?
. Internal tibial torsion and procurvatum
. Internal tibial torsion and recurvatum
. External tibial torsion and procurvatum
. External tibial torsion and recurvatum
. Internal tibial torsion only

Correct Answer & Explanation

. Internal tibial torsion and procurvatum

Explanation

The classic multiplanar deformity in infantile Blount disease consists of varus, internal tibial torsion, and procurvatum (anterior bowing). A successful osteotomy must correct all these planes to restore normal mechanical alignment.

Question 413

Topic: 3. Adult Reconstruction (Hip & Knee)

According to the American Academy of Orthopaedic Surgeons (AAOS) guidelines, which of the following is an acceptable strategy for venous thromboembolism (VTE) prophylaxis in a standard-risk patient undergoing elective total hip arthroplasty (THA)?

. Aspirin alone
. Mechanical prophylaxis alone
. Unfractionated heparin infusion
. Inferior vena cava filter placement
. Observation without prophylaxis

Correct Answer & Explanation

. Aspirin alone

Explanation

The AAOS guidelines support the use of aspirin for VTE prophylaxis in standard-risk patients undergoing elective THA or TKA. Mechanical prophylaxis alone is generally insufficient for pharmacological prophylaxis unless anticoagulants are strictly contraindicated.

Question 414

Topic: 3. Adult Reconstruction (Hip & Knee)

A 65-year-old male with a history of a provoked deep vein thrombosis (DVT) 5 years ago is scheduled for a total hip arthroplasty (THA). According to major consensus guidelines, what is the most appropriate VTE prophylaxis regimen?

. Aspirin 81 mg daily for 2 weeks
. Low-molecular-weight heparin (LMWH) for up to 35 days
. Mechanical compression stockings alone for 4 weeks
. Clopidogrel for 14 days
. Inferior vena cava filter placement prior to surgery

Correct Answer & Explanation

. Low-molecular-weight heparin (LMWH) for up to 35 days

Explanation

Patients with a prior history of VTE are considered high-risk for postoperative thromboembolic events following THA. In such patients, aggressive pharmacological prophylaxis, such as LMWH for an extended duration (up to 35 days), is recommended over aspirin alone.

Question 415

Topic: 3. Adult Reconstruction (Hip & Knee)

According to the American College of Chest Physicians (ACCP) guidelines, what is the recommended duration of pharmacological VTE prophylaxis following a routine total hip arthroplasty (THA)?

. 3 to 5 days
. 10 to 14 days, extended up to 35 days
. 60 days
. 90 days
. Lifelong

Correct Answer & Explanation

. 10 to 14 days, extended up to 35 days

Explanation

ACCP guidelines recommend that patients undergoing major orthopedic surgery, such as THA, receive pharmacological VTE prophylaxis for a minimum of 10 to 14 days. Extending this prophylaxis up to 35 days is suggested, particularly for patients at higher risk of VTE.

Question 416

Topic: Total Hip Arthroplasty (THA)

While VTE rates are similar across total hip arthroplasty (THA) approaches, the direct anterior approach carries a unique risk of injury to which of the following structures?

. Sciatic nerve
. Superior gluteal nerve
. Lateral femoral cutaneous nerve
. Obturator nerve
. Pudendal nerve

Correct Answer & Explanation

. Lateral femoral cutaneous nerve

Explanation

The direct anterior approach to the hip utilizes the internervous plane between the sartorius and tensor fasciae latae. It uniquely places the lateral femoral cutaneous nerve at risk, which can lead to meralgia paresthetica.

Question 417

Topic: 3. Adult Reconstruction (Hip & Knee)

According to the American Academy of Orthopaedic Surgeons (AAOS) clinical practice guidelines, which of the following is an acceptable and highly recommended venous thromboembolism (VTE) prophylaxis regimen for a standard-risk patient undergoing an elective total hip arthroplasty?

. Aspirin alone
. Therapeutic unfractionated heparin
. Inferior vena cava (IVC) filter placement
. Warfarin with a target INR of 3.5 to 4.5
. Low-dose continuous aspirin and clopidogrel combination

Correct Answer & Explanation

. Aspirin alone

Explanation

The AAOS guidelines support the use of Aspirin as a safe and effective VTE prophylaxis option for standard-risk patients following total joint arthroplasty. Aspirin has been shown to be non-inferior to other chemical prophylactic agents while carrying a significantly lower risk of bleeding complications.

Question 418

Topic: 3. Adult Reconstruction (Hip & Knee)

A 65-year-old female with a known history of Factor V Leiden and a prior unprovoked deep vein thrombosis is scheduled for a total hip arthroplasty. According to current guidelines, what is the most appropriate VTE prophylaxis strategy for this patient postoperatively?

. Aspirin 81 mg twice daily for 4 weeks
. Mechanical prophylaxis alone using sequential compression devices
. Low-molecular-weight heparin (LMWH) for at least 4 weeks
. Routine preoperative placement of a retrievable IVC filter
. Tranexamic acid administration for 14 days

Correct Answer & Explanation

. Low-molecular-weight heparin (LMWH) for at least 4 weeks

Explanation

Patients with a history of prior VTE or known hypercoagulable states are at high risk for postoperative thromboembolic events. In these high-risk individuals, potent chemical prophylaxis such as LMWH or Warfarin is indicated over Aspirin alone.

Question 419

Topic: 3. Adult Reconstruction (Hip & Knee)

A patient with standard risk factors is scheduled for an elective primary total hip arthroplasty (THA). According to the clinical practice guidelines from the American Academy of Orthopaedic Surgeons (AAOS), which of the following is an acceptable routine pharmacologic agent for the prevention of venous thromboembolism (VTE)?

. Unfractionated heparin continuous infusion
. Aspirin
. Clopidogrel
. Intravenous tissue plasminogen activator (tPA)
. Lifelong warfarin therapy

Correct Answer & Explanation

. Aspirin

Explanation

The AAOS guidelines state that aspirin is an acceptable and effective option for VTE prophylaxis in standard-risk patients undergoing elective THA. It provides similar efficacy to more potent anticoagulants with a lower risk of bleeding.

Question 420

Topic: 3. Adult Reconstruction (Hip & Knee)

A 68-year-old female is preparing for an elective total hip arthroplasty. She has a history of a pulmonary embolism 3 years ago following a general surgical procedure. Which of the following VTE prophylaxis strategies is most appropriate for this high-risk patient?

. Aspirin 81 mg twice daily for 28 days
. Pneumatic compression devices alone
. Low-molecular-weight heparin (LMWH) or a Direct Oral Anticoagulant (DOAC) for up to 35 days
. Inferior vena cava (IVC) filter placement preoperatively
. Early mobilization without pharmacologic prophylaxis

Correct Answer & Explanation

. Low-molecular-weight heparin (LMWH) or a Direct Oral Anticoagulant (DOAC) for up to 35 days

Explanation

Patients with a prior history of VTE are considered high-risk. Extended-duration prophylaxis (up to 35 days) with a potent agent like LMWH or a DOAC is recommended over aspirin or mechanical prophylaxis alone.

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