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3. Adult Reconstruction (Hip & Knee) MCQs

Practice Set 34 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 661

Topic: Total Knee Arthroplasty (TKA)

A 50-year-old patient undergoes an opening wedge High Tibial Osteotomy (HTO) for medial compartment osteoarthritis. Which of the following is a known disadvantage or potential complication specifically associated with the opening wedge technique, as described in the case?

The image shows a post-operative radiograph of an opening wedge HTO.

. Loss of bone stock making TKA technically difficult
. Increased patellar height
. Risk of peroneal nerve injury
. Late collapse with loss of correction
. Disruption of the tibiofibular joint

Correct Answer & Explanation

. Late collapse with loss of correction

Explanation

Correct Answer: DThe case states that the opening wedge osteotomy 'has the disadvantage of having to use bone graft and late collapse with loss of correction'. This directly identifies 'late collapse with loss of correction' as a specific disadvantage of the opening wedge technique.A. Loss of bone stock making TKA technically difficultis a disadvantage specifically attributed to closing wedge osteotomy.B. Increased patellar heightis associated with closing wedge osteotomy, while opening wedge osteotomy is noted to lower patellar height.C. Risk of peroneal nerve injuryis a specific risk associated with closing wedge osteotomy, particularly with proximal fibular osteotomy or disruption of the tibiofibular joint.E. Disruption of the tibiofibular jointis mentioned as a potential consequence of closing wedge osteotomy.

Question 662

Topic: Total Knee Arthroplasty (TKA)

The case discusses the comparative outcomes of HTO versus UKA, referencing a review by Dettoni et al. (2010). What was the primary conclusion of this review regarding the superiority of one treatment over the other for medial unicompartmental arthrosis of the knee?

. UKA consistently shows significantly better survivorship and functional outcomes.
. HTO consistently shows significantly better survivorship and functional outcomes.
. Both treatments produce durable and predictable outcomes with correct indications, with no evidence of superior results of one over the other.
. HTO is superior for high-demand patients, while UKA is superior for low-demand patients.
. The review found no reliable data to compare the two treatments effectively.

Correct Answer & Explanation

. Both treatments produce durable and predictable outcomes with correct indications, with no evidence of superior results of one over the other.

Explanation

Correct Answer: CThe case explicitly states, referencing Dettoni et al., that 'They concluded that with the correct indications, both treatments produce durable and predictable outcomes in the treatment of medial unicompartmental arthrosis of the knee. There is no evidence of superior results of one treatment over the other.'A. UKA consistently shows significantly better survivorship and functional outcomes.The review reported 'slightly better results for UKA in terms of survivorship and functional outcome,' but immediately qualified this by stating 'the differences are not remarkable' and 'no evidence of superior results of one treatment over the other.'B. HTO consistently shows significantly better survivorship and functional outcomes.This is incorrect, as the review suggested slightly better results for UKA, though not remarkably so.D. HTO is superior for high-demand patients, while UKA is superior for low-demand patients.While this is the clinical recommendation made by the candidate in the case based on practical considerations (accelerated wear of UKA in high-demand jobs), the Dettoni et al. review's conclusion was specifically about the lack of evidence forsuperiorityin outcomes between the two treatments when indications are correct, not a direct endorsement of one over the other based on activity level in terms ofoverall outcome superiority.E. The review found no reliable data to compare the two treatments effectively.This is incorrect. The review did compare studies but noted that 'the study methods are not homogeneous' and that most papers reported on closing wedge HTOs, which limited strong conclusions, but it still drew a conclusion about the comparable efficacy.

Question 663

Topic: Total Knee Arthroplasty (TKA)

A 47-year-old patient, similar to the bricklayer in the case, undergoes a High Tibial Osteotomy (HTO). Several years later, his osteoarthritis has progressed, and he now requires a Total Knee Arthroplasty (TKA). The surgeon notes that the previous HTO has complicated the TKA conversion. Which of the following is a specific implication of a prior opening wedge HTO on patellar height during subsequent TKA?

The image shows a post-operative radiograph of an HTO, which may have implications for patellar height.

. It typically leads to patella alta, making patellar tracking easier.
. It typically leads to patella baja, which can complicate patellar tracking and component placement.
. It has no significant effect on patellar height, simplifying TKA conversion.
. It causes lateral patellar subluxation, requiring a lateral release.
. It increases the risk of patellar fracture during TKA.

Correct Answer & Explanation

. It typically leads to patella baja, which can complicate patellar tracking and component placement.

Explanation

Correct Answer: BThe case states, 'More recent studies show that closing wedge osteotomy increases patellar height, whereas opening wedge osteotomy lowers patellar height and this can have implications following TKA.' Patella baja (lowered patellar height) can significantly complicate TKA by making patellar tracking more difficult, increasing the risk of patellar impingement, and potentially affecting the choice and placement of prosthetic components.A. It typically leads to patella alta, making patellar tracking easier.This is incorrect. Opening wedge HTO lowers patellar height, leading to patella baja. Closing wedge HTO increases patellar height.C. It has no significant effect on patellar height, simplifying TKA conversion.This is incorrect, as the case explicitly states it 'can have implications following TKA.'D. It causes lateral patellar subluxation, requiring a lateral release.While patellar tracking issues can occur, the primary effect on patellar height is lowering it, not necessarily causing lateral subluxation as a direct consequence of the osteotomy type itself.E. It increases the risk of patellar fracture during TKA.While TKA after HTO can have increased risks, the direct implication on patellar height is patella baja, not necessarily an increased fracture risk as the primary concern related to patellar height.

Question 664

Topic: Total Knee Arthroplasty (TKA)

The candidate in the case mentions difficulties with conversion of HTO to TKA. Beyond patellar height changes, what is another significant challenge or disadvantage of a prior closing wedge HTO when converting to a Total Knee Arthroplasty (TKA)?

. Increased risk of infection due to retained hardware
. Loss of bone stock making TKA technically difficult
. Improved bone quality for implant fixation
. Reduced need for soft tissue balancing
. Easier restoration of the mechanical axis

Correct Answer & Explanation

. Loss of bone stock making TKA technically difficult

Explanation

Correct Answer: BThe case states that closing wedge osteotomy 'has the risk of peroneal nerve injury, there is also loss of bone stock making it technically difficult to perform TKA.' This loss of bone stock, particularly from the proximal tibia, can significantly complicate the preparation of the tibial plateau for TKA components, potentially requiring bone grafting or specialized implants.A. Increased risk of infection due to retained hardwareis a general risk with any retained hardware, but 'loss of bone stock' is a more specific and direct difficulty related to theconversionitself, as highlighted in the text.C. Improved bone quality for implant fixationis incorrect; the loss of bone stock generally implies a more challenging bone bed for TKA.D. Reduced need for soft tissue balancingis incorrect; prior HTO can alter soft tissue tension and ligamentous balance, often making TKA soft tissue balancing more complex, not less.E. Easier restoration of the mechanical axisis incorrect; the altered anatomy and bone loss from HTO can make accurate restoration of the mechanical axis more challenging during TKA.

Question 665

Topic: 3. Adult Reconstruction (Hip & Knee)

A 55-year-old male with symptomatic isolated medial compartment knee osteoarthritis desires a unicompartmental knee arthroplasty (UKA). Which of the following is an absolute contraindication for this procedure?

. Age less than 60 years
. A body mass index (BMI) of 32 kg/m2
. An uncorrectable varus deformity of 20 degrees
. Intact anterior cruciate ligament (ACL)
. Knee flexion to 120 degrees

Correct Answer & Explanation

. An uncorrectable varus deformity of 20 degrees

Explanation

Uncorrectable varus deformity, typically greater than 15 degrees, is a contraindication for medial UKA. Other classic contraindications include ACL deficiency, inflammatory arthritis, and a fixed flexion contracture > 15 degrees.

Question 666

Topic: 3. Adult Reconstruction (Hip & Knee)

A 70-year-old female with severe rheumatoid arthritis undergoes a primary total knee arthroplasty. Intraoperatively, the posterior cruciate ligament (PCL) is found to be incompetent and severely attenuated. The medial and lateral collateral ligaments are intact. Which of the following implant designs is most appropriate?

. Cruciate-retaining (CR)
. Posterior-stabilized (PS)
. Constrained condylar knee (CCK)
. Rotating hinge
. Unicompartmental knee

Correct Answer & Explanation

. Posterior-stabilized (PS)

Explanation

In the presence of an incompetent PCL but intact collateral ligaments, a posterior-stabilized (PS) design is indicated. The cam-and-post mechanism substitutes for the absent PCL to prevent anterior translation of the femur on the tibia during flexion.

Question 667

Topic: 3. Adult Reconstruction (Hip & Knee)

A 55-year-old female presents with medial joint line knee pain. Radiographs demonstrate isolated medial compartment osteoarthritis. Which of the following is an absolute contraindication for a medial unicompartmental knee arthroplasty (UKA)?

. Age greater than 50 years
. Body Mass Index (BMI) of 32
. Inflammatory arthritis (e.g., Rheumatoid Arthritis)
. Patellofemoral chondromalacia without anterior knee pain
. Fixed flexion contracture of 5 degrees

Correct Answer & Explanation

. Inflammatory arthritis (e.g., Rheumatoid Arthritis)

Explanation

Inflammatory arthropathies, such as rheumatoid arthritis, are classic contraindications for unicompartmental knee arthroplasty due to the global, progressive nature of the joint destruction. Obesity and mild asymptomatic patellofemoral changes are no longer strict contraindications.

Question 668

Topic: 3. Adult Reconstruction (Hip & Knee)

During a Total Knee Arthroplasty (TKA), the surgeon determines that the knee is tight in full extension but perfectly balanced in 90 degrees of flexion. Which of the following is the most appropriate surgical step to balance the knee?

. Upsize the femoral component
. Downsize the femoral component
. Recess the posterior cruciate ligament (PCL)
. Resect more distal femur and release the posterior capsule
. Resect more proximal tibia

Correct Answer & Explanation

. Resect more distal femur and release the posterior capsule

Explanation

A knee that is tight in extension but balanced in flexion indicates an isolated tight extension gap. Corrective measures include resecting more of the distal femur or releasing the posterior capsule, which affects only the extension space.

Question 669

Topic: 3. Adult Reconstruction (Hip & Knee)

A patient complains of a painful "catching" or "popping" sensation at the anterior knee when extending from a flexed position, 1 year after a posterior-stabilized total knee arthroplasty (TKA). What is the underlying pathophysiology of this complication?

. Hypertrophy of the infrapatellar fat pad impinging in the joint space
. A fibrotic nodule forming on the undersurface of the distal quadriceps tendon engaging the intercondylar box
. Asymmetric polyethylene wear leading to subluxation of the femoral component
. Loosening of the patellar component leading to metal-on-plastic impingement
. Excessive anterior placement of the femoral component

Correct Answer & Explanation

. A fibrotic nodule forming on the undersurface of the distal quadriceps tendon engaging the intercondylar box

Explanation

Patellar clunk syndrome occurs primarily in posterior-stabilized TKA designs when a fibrous nodule forms on the deep surface of the distal quadriceps tendon. As the knee extends from flexion, the nodule catches on the superior edge of the femoral intercondylar box.

Question 670

Topic: 3. Adult Reconstruction (Hip & Knee)

A 35-year-old female presents with severe lateral compartment knee osteoarthritis and a 15-degree valgus deformity due to prior trauma. She desires to return to high-impact activities. Which of the following procedures is most appropriate to unload her lateral compartment?

. Medial opening wedge high tibial osteotomy (HTO)
. Medial closing wedge distal femoral osteotomy (DFO)
. Lateral unicompartmental knee arthroplasty
. Total knee arthroplasty using a constrained condylar knee (CCK) implant
. Medial unicompartmental knee arthroplasty

Correct Answer & Explanation

. Medial closing wedge distal femoral osteotomy (DFO)

Explanation

For valgus knee osteoarthritis in a young, active patient, the deformity is primarily in the distal femur. A medial closing wedge (or lateral opening wedge) distal femoral osteotomy correctly addresses the mechanical axis while sparing the joint for future arthroplasty.

Question 671

Topic: 3. Adult Reconstruction (Hip & Knee)

A 60-year-old female with hallux rigidus previously underwent a first MTP joint silastic implant arthroplasty. She now presents with recurrent pain, massive swelling, and radiographic evidence of severe periprosthetic lucencies and bone loss. What is the most likely diagnosis?

. Septic arthritis secondary to Staphylococcus epidermidis
. Silicone synovitis and particulate-induced osteolysis
. Gouty arthropathy exacerbation
. Aseptic loosening secondary to implant undersizing
. Stress fracture of the second metatarsal

Correct Answer & Explanation

. Silicone synovitis and particulate-induced osteolysis

Explanation

Silastic (silicone) implants for hallux rigidus have largely fallen out of favor due to the high risk of silicone synovitis. This foreign body reaction leads to aggressive particulate-induced osteolysis and severe bone loss.

Question 672

Topic: Total Knee Arthroplasty (TKA)
Which of the following patients is the most ideal candidate for a medial opening wedge high tibial osteotomy (HTO)?
. A 45-year-old heavy smoker with medial compartment OA and a 15-degree flexion contracture
. A 50-year-old active male with isolated medial compartment OA, intact ligaments, and a 5-degree varus malalignment
. A 55-year-old female with combined medial and symptomatic patellofemoral OA with 10 degrees of varus
. A 60-year-old male with medial OA, previous subtotal lateral meniscectomy, and grade III lateral chondromalacia
. A 40-year-old female with inflammatory rheumatoid arthritis and a 5-degree varus deformity

Correct Answer & Explanation

. A 50-year-old active male with isolated medial compartment OA, intact ligaments, and a 5-degree varus malalignment

Explanation

The ideal candidate for an HTO is a young, active patient with isolated unicompartmental osteoarthritis, correctable malalignment, and intact ligaments. Contraindications include inflammatory arthritis, flexion contractures >15 degrees, patellofemoral arthritis, and lateral compartment disease.

Question 673

Topic: 3. Adult Reconstruction (Hip & Knee)

According to classic Kozinn and Scott criteria, which of the following is considered an absolute contraindication for a medial unicompartmental knee arthroplasty (UKA)?

. Patient age greater than 60 years
. Asymptomatic patellofemoral osteophytes
. Inflammatory arthropathy
. A flexion contracture of 10 degrees
. Passively correctable 10-degree varus deformity

Correct Answer & Explanation

. Inflammatory arthropathy

Explanation

Inflammatory arthropathy is an absolute contraindication for UKA due to the systemic, progressive nature of the disease affecting all compartments. Correctable varus <15 degrees, flexion contracture <15 degrees, and asymptomatic patellofemoral changes are acceptable parameters for UKA.

Question 674

Topic: 3. Adult Reconstruction (Hip & Knee)

Which of the following is considered an absolute contraindication for a medial unicompartmental knee arthroplasty (UKA) in a patient with medial compartment knee osteoarthritis?

. Age greater than 60 years
. Body Mass Index (BMI) greater than 30
. Fixed varus deformity of 20 degrees
. Anterior cruciate ligament (ACL) deficiency
. Flexion contracture of 10 degrees

Correct Answer & Explanation

. Fixed varus deformity of 20 degrees

Explanation

A fixed angular deformity (e.g., fixed varus greater than 10 degrees) that cannot be passively corrected is an absolute contraindication to UKA, as the procedure relies on intact soft-tissue envelopes for balancing. Age, BMI, and even ACL deficiency (in specific scenarios) are considered relative or controversial contraindications.

Question 675

Topic: 3. Adult Reconstruction (Hip & Knee)

A 42-year-old active laborer presents with medial knee pain. Radiographs demonstrate medial compartment osteoarthritis and a mechanical axis that passes through the medial compartment with 8 degrees of varus. Range of motion is 0-130 degrees. The lateral and patellofemoral compartments are well preserved. What is the most appropriate surgical option?

. Total knee arthroplasty
. Proximal tibial osteotomy (High Tibial Osteotomy)
. Distal femoral osteotomy
. Arthroscopic debridement and lavage
. Unicompartmental knee arthroplasty

Correct Answer & Explanation

. Proximal tibial osteotomy (High Tibial Osteotomy)

Explanation

High Tibial Osteotomy (HTO) is the ideal surgical treatment for young, highly active patients with isolated medial compartment osteoarthritis and varus malalignment. It unloads the medial compartment, significantly delaying the need for arthroplasty while allowing the patient to maintain a demanding lifestyle.

Question 676

Topic: 3. Adult Reconstruction (Hip & Knee)

A 65-year-old patient presents with increasing pain and instability in their left knee, 10 years after a primary total knee arthroplasty. The provided radiographs are shown.

. Well-fixed components with early signs of polyethylene wear.
. Periprosthetic fracture of the distal femur.
. Aseptic loosening with significant osteolysis and bone loss.
. Acute periprosthetic joint infection with component migration.
. Patellar maltracking with associated patellofemoral arthritis.

Correct Answer & Explanation

. Aseptic loosening with significant osteolysis and bone loss.

Explanation

Correct Answer: CThe radiographs clearly demonstrate widespread lucency around both the femoral and tibial components, indicating loss of fixation. There is significant subsidence of the tibial component and extensive osteolysis, particularly in the proximal tibia and distal femur. These findings are classic for aseptic loosening. While periprosthetic joint infection (PJI) is always in the differential for a painful TKA, the radiographic findings alone are more definitively characteristic of aseptic loosening and associated bone loss. There is no clear evidence of a periprosthetic fracture, and the extent of loosening and osteolysis goes beyond early polyethylene wear or isolated patellar issues.

Question 677

Topic: 3. Adult Reconstruction (Hip & Knee)

A 72-year-old patient presents with a painful left total knee arthroplasty. Radiographs are provided. The surgeon notes extensive bone loss involving a major portion of both the distal femoral condyles and the proximal tibial plateau, requiring significant augmentation and likely long-stemmed components.

. Femur Type 2A, Tibia Type 2A
. Femur Type 2B, Tibia Type 2B
. Femur Type 3, Tibia Type 3
. Femur Type 1, Tibia Type 2B
. Femur Type 2B, Tibia Type 3

Correct Answer & Explanation

. Femur Type 3, Tibia Type 3

Explanation

Correct Answer: CThe Anderson Orthopaedic Research Institute (AORI) classification for bone loss is crucial in revision TKA planning. Type 1 involves intact metaphyseal bone with minor defects. Type 2 involves damaged metaphyseal bone with loss of cancellous bone, categorized as 2A (one condyle/plateau) or 2B (both condyles/plateaux). Type 3 describes deficient metaphyseal bone where bone loss comprises a major portion of either condyle or plateau, often associated with ligament detachment and requiring long-stemmed implants, bone grafts, or custom prostheses. The case description explicitly states "extensive bone loss involving a major portion of both the distal femoral condyles and the proximal tibial plateau," which directly corresponds to AORI Type 3 for both the femur and tibia. The radiographs support this with widespread osteolysis and significant bone defects.

Question 678

Topic: Total Knee Arthroplasty (TKA)

The patient, described as "reasonably young," has extensive bone loss around the failed total knee replacement. The surgeon is planning the revision procedure.

. Exclusive use of cement with screws and mesh to fill defects.
. Primary reliance on modular augmentation with metal wedges or blocks.
. Restoration of bone stock using structural or morselized bone graft, potentially with metaphyseal sleeves.
. Immediate consideration of a custom-made hinged prosthesis due to the severity.
. Minimizing surgical time by avoiding complex bone grafting techniques.

Correct Answer & Explanation

. Restoration of bone stock using structural or morselized bone graft, potentially with metaphyseal sleeves.

Explanation

Correct Answer: CThe case explicitly states, "In this patient who is reasonably young restoration of bone stock is preferable, because of likelihood of further revision surgery." For younger patients with extensive bone loss, preserving and restoring bone stock is paramount to facilitate potential future revisions. This is best achieved through the use of bone grafting (structural or morselized) and/or modular metaphyseal sleeves, which allow for biological ingrowth and reconstruction of the metaphyseal bone. While cement, modular augments, or even hinged prostheses can address defects, they do not primarily restore bone stock. Avoiding complex bone grafting for the sake of surgical time would compromise the long-term outcome and future revision potential in a young patient.

Question 679

Topic: 3. Adult Reconstruction (Hip & Knee)

The lateral radiograph of the failed total knee replacement clearly demonstrates anterior femoral cortical notching.

. It indicates a high likelihood of periprosthetic joint infection.
. It is a common finding in well-functioning total knee replacements and has no clinical significance.
. It suggests a technical error during primary implantation, increasing the risk of periprosthetic fracture.
. It is a sign of severe polyethylene wear and subsequent osteolysis.
. It is primarily associated with posterior cruciate ligament insufficiency.

Correct Answer & Explanation

. It suggests a technical error during primary implantation, increasing the risk of periprosthetic fracture.

Explanation

Correct Answer: CAnterior femoral cortical notching is a well-recognized complication of total knee arthroplasty, typically resulting from over-resection of the distal femur or improper sizing of the femoral component during the primary surgery. This notching creates a stress riser in the anterior femoral cortex, significantly weakening the bone and increasing the risk of a supracondylar periprosthetic femoral fracture, especially with minor trauma. It is not directly indicative of infection, polyethylene wear, or PCL insufficiency, nor is it a benign finding.

Question 680

Topic: 3. Adult Reconstruction (Hip & Knee)

The candidate initially suggests that the radiographs are "suggestive of infection until proven otherwise," despite the examiner later confirming aseptic loosening.

. Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).
. Presence of a continuous radiolucent line greater than 2mm at the bone-cement interface.
. Progressive subsidence of the tibial component on serial radiographs.
. Pain with activity that improves with rest.
. Development of anterior femoral cortical notching.

Correct Answer & Explanation

. Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).

Explanation

Correct Answer: AIn the initial workup of a painful total knee arthroplasty, differentiating between aseptic loosening and periprosthetic joint infection (PJI) is critical. Elevated inflammatory markers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are highly sensitive indicators of PJI. While not definitive on their own, they are the most indicative of infection among the given options. A continuous radiolucent line greater than 2mm and progressive component subsidence are classic radiographic signs of aseptic loosening. Pain with activity that improves with rest is a common symptom of mechanical loosening. Anterior femoral cortical notching is a technical complication related to fracture risk, not directly to infection.

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