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 441
Topic: Total Hip Arthroplasty (THA)
A patient undergoes open reduction and internal fixation for a Vancouver C periprosthetic femur fracture located well below a stable, cemented THA stem. The surgeon utilizes a lateral locking plate. To minimize the biomechanical risk of a subsequent interprosthetic stress fracture, how should the proximal aspect of the plate be positioned?
Correct Answer & Explanation
. Overlap the femoral stem by at least two cortical diameters
Explanation
When plating a Vancouver C fracture, the plate should overlap the existing well-fixed stem by a minimum of two cortical diameters. Ending the plate near the tip of the stem creates a massive stress riser, predisposing the patient to an interprosthetic fracture.
Question 442
Topic: 3. Adult Reconstruction (Hip & Knee)
A 72-year-old female presents with a periprosthetic femur fracture around a cemented total hip arthroplasty after a fall. Radiographs demonstrate a fracture around the distal aspect of the stem with profound radiolucent lines at the cement-bone interface, indicative of a loose stem, but with excellent proximal bone stock. According to the Vancouver classification, what is the recommended treatment for this fracture?
Correct Answer & Explanation
. Revision to a long uncemented diaphyseal-engaging stem
Explanation
A fracture around a loose femoral stem with adequate remaining bone stock is classified as a Vancouver B2 fracture. The standard of care is revision arthroplasty using a long, diaphyseal-engaging extensively porous-coated or fluted tapered stem.
Question 443
Topic: 3. Adult Reconstruction (Hip & Knee)
A 32-year-old male sustains a high-energy motor vehicle collision resulting in a vertically oriented, displaced femoral neck fracture (Pauwels type III). What is the most mechanically sound construct for surgical fixation of this injury?
Correct Answer & Explanation
. Sliding hip screw with a derotational cancellous screw
Explanation
Pauwels type III fractures experience high shear forces due to their vertical orientation. A sliding hip screw with a derotational screw provides superior biomechanical stability compared to parallel cancellous screws for these high-shear fractures.
Question 444
Topic: 3. Adult Reconstruction (Hip & Knee)
The examiner praises the second candidate for asking about the patient's symptoms, previous treatments, and expectations before committing to a management plan. This approach BEST exemplifies which principle of patient care?
Correct Answer & Explanation
. Employing a patient-centered approach to tailor treatment to individual needs and goals.
Explanation
Correct Answer: CThe second candidate's approach of inquiring about symptoms, previous treatments, and patient expectations before recommending surgery demonstrates a strong patient-centered approach (Option C). This is crucial in orthopedic decision-making, especially for elective procedures like arthroplasty. It ensures that the chosen treatment aligns with the patient's functional goals and quality of life. Prioritizing imaging over clinical presentation (Option A) is a mistake the first candidate made. Adhering strictly to algorithms (Option B) without considering individual patient factors can lead to suboptimal outcomes. Delaying treatment (Option D) is not the intent; rather, it's about gatheringrelevantinformation to make an informed decision. Focusing solely on anatomical pathology (Option E) ignores the patient's functional limitations and desired outcomes, which is a critical component of successful treatment.
Question 445
Topic: 3. Adult Reconstruction (Hip & Knee)
According to the Musculoskeletal Infection Society (MSIS) criteria, which of the following is considered a definitive major criterion for diagnosing a periprosthetic joint infection?
Correct Answer & Explanation
. A sinus tract communicating with the prosthesis
Explanation
The MSIS major criteria for definitive periprosthetic joint infection are a sinus tract communicating with the prosthesis or two positive periprosthetic cultures with phenotypically identical organisms. The other options are considered minor criteria.
Question 446
Topic: 3. Adult Reconstruction (Hip & Knee)
A 68-year-old male presents with chronic right knee pain 3 years after a total knee arthroplasty. Aspiration yields synovial fluid with a WBC count of 4,500 cells/uL and 85% polymorphonuclear neutrophils (PMNs). According to the Musculoskeletal Infection Society (MSIS) criteria for chronic PJI, what is the most appropriate interpretation and next step?
Correct Answer & Explanation
. The fluid is highly suspicious for chronic PJI; obtain Alpha-defensin, CRP, and ESR to confirm
Explanation
In chronic total knee arthroplasty, synovial fluid WBC > 3,000 cells/uL or PMN > 80% is highly indicative of a periprosthetic joint infection (PJI). Further confirmatory tests (ESR, CRP, Alpha-defensin) are recommended before undertaking two-stage revision.
Question 447
Topic: 3. Adult Reconstruction (Hip & Knee)
A 40-year-old male undergoes radial head replacement for a complex Mason-Johnston Type III fracture. Post-operatively, he develops progressive elbow stiffness. Which complication is most likely contributing to this stiffness?
Correct Answer & Explanation
. Heterotopic ossification
Explanation
Heterotopic ossification (HO) is a common and challenging complication after elbow trauma and surgery, especially in the context of complex fractures and dislocations. It involves the formation of new bone in soft tissues around the joint, leading to progressive loss of motion and stiffness. While infection and aseptic loosening are possible complications, HO is particularly known for causing severe stiffness after elbow surgery. Radial and ulnar nerve palsies would primarily cause neurological symptoms rather than direct stiffness.
Question 448
Topic: 3. Adult Reconstruction (Hip & Knee)
A 16-year-old patient undergoes open reduction and temporary K-wire fixation for an unstable acute posterior sternoclavicular joint dislocation. Six weeks post-operatively, the patient develops sudden onset chest pain, dyspnea, and a new heart murmur.
Based on the provided case information and the known risks of K-wire fixation for SC joint injuries, what is the MOST likely complication this patient is experiencing?
Correct Answer & Explanation
. K-wire migration into mediastinal structures
Explanation
Correct Answer: CThe symptoms of sudden onset chest pain, dyspnea, and a new heart murmur in a patient with K-wire fixation across the sternoclavicular joint are highly suggestive ofK-wire migration into mediastinal structures. The case explicitly states that K-wires are 'highly discouraged due to significant complication rates, including migration into mediastinal structures (heart, great vessels, lung).' This is a historically significant and potentially fatal complication. Superficial wound infection (A) would present with local signs of inflammation. Recurrent dislocation (B) would typically present with pain and deformity, not acute cardiac/respiratory symptoms. Post-traumatic osteolysis (D) is a chronic, painful condition, not an acute life-threatening event. Supraclavicular nerve neuropraxia (E) would cause sensory deficits in the neck/shoulder, not chest pain or dyspnea.
Question 449
Topic: 3. Adult Reconstruction (Hip & Knee)
A 55-year-old patient has suffered from chronic, symptomatic anterior sternoclavicular joint instability for over a year, despite extensive non-operative management including physical therapy and injections. She experiences persistent pain, clicking, and functional limitations.
What is the most appropriate surgical intervention for this patient's chronic symptomatic anterior sternoclavicular joint instability?
Correct Answer & Explanation
. Medial clavicle resection arthroplasty or ligament reconstruction
Explanation
Correct Answer: CFor chronic symptomatic sternoclavicular (SC) joint instability (anterior or posterior) that has failed adequate non-operative management (typically 3-6 months), surgical intervention is indicated. The primary surgical options aremedial clavicle resection arthroplasty(especially for degenerative arthritis or persistent pain with some anterior instability) orligament reconstruction. Ligament reconstruction, often using autograft (e.g., semitendinosus, palmaris longus) in a figure-of-8 pattern, is the mainstay for restoring stability. Emergent closed reduction (A) is for acute injuries. Primary repair of the anterior SC ligament (B) might be attempted in acute settings if the tissue quality is good, but for chronic instability, the ligaments are often attenuated or scarred, making reconstruction more effective. Temporary K-wire fixation (D) is strongly discouraged due to high complication rates. Observation with continued pain medication (E) is not appropriate for debilitating chronic symptoms that have failed conservative care.
Question 450
Topic: 3. Adult Reconstruction (Hip & Knee)
A 48-year-old male, 18 months after internal fixation of a displaced femoral neck fracture, presents with persistent hip pain and progressive collapse of the femoral head, as depicted in the provided image. Radiographs confirm subchondral collapse and secondary osteoarthritis. The most likely etiology for this complication, as described in the case, is:
Correct Answer & Explanation
. C. Avascular necrosis resulting from retinacular vessel disruption
Explanation
Correct Answer: CThe correct answer is C. The clinical presentation of persistent hip pain, progressive collapse of the femoral head, and secondary osteoarthritis, occurring months to years after a femoral neck fracture, is classic for avascular necrosis (AVN). The case states, 'Avascular necrosis is a devastating complication primarily associated with femoral neck fractures. It results from the disruption of the retinacular vessels at the time of injury or due to elevated intracapsular pressure. It typically presents months to years after the index procedure with subchondral collapse and secondary osteoarthritis.'A. Implant cutout typically presents earlier with acute pain and radiographic evidence of screw migration through the articular surface, not progressive collapse over 18 months.B. Nonunion is a failure of the fracture to heal, often presenting with persistent pain and progressive hardware failure (e.g., screw breakage, telescoping), but not typically with subchondral collapse of the femoral head itself, unless AVN is a contributing factor.D. Surgical site infection would typically present with signs of inflammation, fever, drainage, and possibly osteolysis, but not primarily with subchondral collapse in this delayed fashion without other infectious signs.E. Stress shielding can occur with overly rigid implants, potentially leading to bone resorption, but it does not typically cause the specific pattern of subchondral collapse and secondary osteoarthritis characteristic of AVN.
Question 451
Topic: 3. Adult Reconstruction (Hip & Knee)
A 72-year-old active female presents with a Garden III displaced femoral neck fracture. She has well-controlled hypertension and is otherwise healthy. Concurrently, a 45-year-old male presents with a Garden III displaced femoral neck fracture after a motorcycle accident. Based on the case's indications, what is the most appropriate primary surgical management for each patient, respectively?
Correct Answer & Explanation
. 72-year-old: Total hip arthroplasty; 45-year-old: Internal fixation
Explanation
In the elderly population with displaced femoral neck fractures, arthroplasty is generally preferred due to the unacceptably high rates of fixation failure, nonunion, and avascular necrosis associated with internal fixation. For the 72-year-old active female with a Garden III (displaced) fracture, arthroplasty (either hemiarthroplasty or total hip arthroplasty, with THA offering superior functional outcomes in active elderly patients as per HEALTH trial) is indicated. For the 45-year-old male with a displaced femoral neck fracture, internal fixation is generally indicated to preserve the native joint when the blood supply to the femoral head is presumed intact or when the patient is young enough that arthroplasty would inevitably lead to multiple future revisions.
Question 452
Topic: 3. Adult Reconstruction (Hip & Knee)
A hospital system is reviewing its hip fracture care pathway to align with current evidence-based guidelines. They are particularly interested in strategies to reduce mortality and complication rates. Based on the 'Summary of Key Literature and Guidelines' in the case, which two recommendations should be prioritized for implementation?
Correct Answer & Explanation
. Implement early surgery (within 24-48 hours of admission) and establish co-management with geriatric or internal medicine services.
Explanation
The American Academy of Orthopaedic Surgeons clinical practice guidelines strongly recommend early surgery, ideally within twenty-four to forty-eight hours of admission, to reduce mortality and complication rates. The guidelines also emphasize the necessity of co-management with geriatric or internal medicine services to optimize preoperative medical status and manage postoperative medical complications, reflecting the multidisciplinary approach required to successfully treat this fragile patient population.
Question 453
Topic: Total Hip Arthroplasty (THA)
During an open posterior approach to the knee for a PCL avulsion fracture, the surgeon must carefully navigate several critical neurovascular structures. Which of the following describes the correct anatomical relationship of the popliteal vein relative to the tibial nerve and popliteal artery in the popliteal fossa?
Correct Answer & Explanation
. C. The popliteal vein lies posterior to the popliteal artery and superficial to the tibial nerve.
Explanation
The correct anatomical order from posterior to anterior in the popliteal fossa is Tibial Nerve, Popliteal Vein, Popliteal Artery. Therefore, the popliteal vein is anterior to the tibial nerve and posterior to the popliteal artery. Option C is the most consistent with this anatomical relationship, where 'superficial' in the context of a posterior approach implies being closer to the skin (anterior) relative to the deeper structures.
Question 454
Topic: 3. Adult Reconstruction (Hip & Knee)
During a primary posterior-stabilized total knee arthroplasty (TKA), the surgeon assesses the gap balances with trial components. The extension gap is perfectly balanced, but the flexion gap is excessively tight. Which of the following is the most appropriate intraoperative adjustment?
Correct Answer & Explanation
. Downsize the femoral component
Explanation
A tight flexion gap with a balanced extension gap requires adjusting only the flexion space. Downsizing the femoral component (reducing its anteroposterior diameter) or increasing the posterior tibial slope will increase the flexion gap without affecting extension.
Question 455
Topic: 3. Adult Reconstruction (Hip & Knee)
A 60-year-old female presents with isolated medial compartment osteoarthritis of the knee and requests a medial unicompartmental knee arthroplasty (UKA). Which of the following conditions represents an absolute contraindication to performing a UKA?
Correct Answer & Explanation
. Inflammatory arthropathy such as rheumatoid arthritis
Explanation
Inflammatory arthritis is an absolute contraindication to UKA due to the high risk of disease progression into the unresurfaced compartments. Minor patellofemoral changes or correctable mild varus deformities are not strict contraindications.
Question 456
Topic: 3. Adult Reconstruction (Hip & Knee)
A 66-year-old female presents 14 months after an uncomplicated posterior-stabilized total knee arthroplasty. She reports a painful, audible catching sensation when actively extending her knee from 40 degrees of flexion to full extension. What is the most likely underlying pathology?
Correct Answer & Explanation
. Fibrous nodule formation engaging the intercondylar box of the femoral component
Explanation
This patient has 'patellar clunk syndrome', a complication specific to posterior-stabilized TKA designs. It occurs when a fibrous nodule forms on the undersurface of the distal quadriceps tendon and catches in the femoral intercondylar box during active extension.
Question 457
Topic: Total Knee Arthroplasty (TKA)
During a total knee arthroplasty (TKA) using a measured resection technique, trial components are placed. The knee is symmetric and balanced in extension, but tight in flexion. Which of the following is the most appropriate intraoperative step to balance the knee?
Correct Answer & Explanation
. Downsize the femoral component and use anterior referencing
Explanation
A knee that is tight in flexion but balanced in extension requires an increase in the flexion gap without affecting the extension gap. This is achieved by downsizing the femoral component (resecting more posterior condyle) or recessing the posterior cruciate ligament.
Question 458
Topic: 3. Adult Reconstruction (Hip & Knee)
A 58-year-old female is evaluated for medial unicompartmental knee osteoarthritis. Which of the following is considered an absolute contraindication for a medial unicompartmental knee arthroplasty (UKA)?
Correct Answer & Explanation
. Inflammatory arthropathy
Explanation
Inflammatory arthropathies, such as rheumatoid arthritis, are absolute contraindications for UKA because the systemic disease will predictably destroy the remaining unreplaced compartments. Minor patellofemoral wear and moderate obesity are relative or non-contraindications depending on surgeon preference.
Question 459
Topic: 3. Adult Reconstruction (Hip & Knee)
A 65-year-old woman is 6 weeks status post a primary total knee arthroplasty. Despite aggressive physical therapy, her active range of motion is 15 to 65 degrees. Radiographs show well-positioned components. What is the most appropriate next step in management?
Correct Answer & Explanation
. Manipulation under anesthesia (MUA)
Explanation
Manipulation under anesthesia (MUA) is most successful when performed between 6 to 12 weeks postoperatively for arthrofibrosis after TKA. Waiting significantly beyond this window allows fibrous tissue to mature, decreasing the success rate of MUA and increasing the risk of periprosthetic fracture.
Question 460
Topic: 3. Adult Reconstruction (Hip & Knee)
During a posterior-stabilized total knee arthroplasty, trial components are placed. The knee is perfectly balanced in full extension but exhibits significant laxity in 90 degrees of flexion. Which of the following adjustments will best balance the knee?
Correct Answer & Explanation
. Upsize the femoral component
Explanation
A knee that is balanced in extension but loose in flexion has an isolated loose flexion gap. Upsizing the femoral component increases the anteroposterior dimension, tightening the flexion gap without affecting the extension gap.
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