Menu

3. Adult Reconstruction (Hip & Knee) MCQs

Practice Set 103 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 2041

Topic: 3. Adult Reconstruction (Hip & Knee)

A 65-year-old female undergoes a primary total knee arthroplasty for a severe, fixed valgus deformity (Ranawat Type II). Intraoperatively, the medial collateral ligament (MCL) is found to be completely incompetent. Which of the following implant constraints is required?

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

Correct Answer & Explanation

. Rotating hinge component

Explanation

In the setting of a completely incompetent or absent medial collateral ligament (MCL), a constrained condylar knee (CCK) design is insufficient because it relies on functional collateral ligaments to prevent coronal plane failure. A linked implant, such as a rotating hinge component, is mandatory to substitute for the global coronal instability.

Question 2042

Topic: 3. Adult Reconstruction (Hip & Knee)

In a cruciate-retaining (CR) total knee arthroplasty, failure to properly balance a tight posterior cruciate ligament (PCL) will most likely result in which of the following kinematic abnormalities?

. Anterior lift-off of the tibial tray during flexion
. Posterior lift-off of the tibial tray during flexion
. Recurvatum instability in full extension
. Medial patellar subluxation
. Symmetric limitation of both flexion and extension

Correct Answer & Explanation

. Anterior lift-off of the tibial tray during flexion

Explanation

An excessively tight PCL in a CR TKA causes exaggerated and premature femoral rollback during flexion. This drives the femoral component off the posterior edge of the tibia, which forces the anterior aspect of the tibial tray to lift off (anterior lift-off), potentially leading to accelerated wear, pain, or component loosening.

Question 2043

Topic: 3. Adult Reconstruction (Hip & Knee)

A patient presents with a painful clunking sensation over the superior pole of the patella when extending the knee from 40 degrees of flexion, 1 year after a posterior-stabilized total knee arthroplasty. What is the pathognomonic cause of 'patellar clunk syndrome'?

. Aseptic loosening of the patellar button
. A fibrous nodule catching in the intercondylar notch of the femoral component
. Rupture of the medial patellofemoral ligament
. Avulsion of the tibial tubercle
. Impingement of a retained posterior cruciate ligament against the tibial spine

Correct Answer & Explanation

. A fibrous nodule catching in the intercondylar notch of the femoral component

Explanation

Patellar clunk syndrome is historically associated with posterior-stabilized (PS) TKA designs. It is caused by the formation of a fibrosynovial nodule on the undersurface of the quadriceps tendon just proximal to the patella. As the knee extends from deep flexion, this nodule catches in the intercondylar box of the femoral component and then forcefully pops out, causing a painful 'clunk'.

Question 2044

Topic: 3. Adult Reconstruction (Hip & Knee)

During a total knee arthroplasty using a standard medial parapatellar arthrotomy, which of the following arteries provides the predominant remaining blood supply to the patella and must be preserved if a lateral retinacular release is performed?

. Supreme geniculate artery
. Medial superior geniculate artery
. Medial inferior geniculate artery
. Superior lateral geniculate artery
. Inferior lateral geniculate artery

Correct Answer & Explanation

. Superior lateral geniculate artery

Explanation

A standard medial parapatellar arthrotomy disrupts the medial blood supply to the patella (supreme, medial superior, and medial inferior geniculate arteries). The superior lateral geniculate artery, located at the superior-lateral pole, becomes the primary blood supply. If a lateral retinacular release is performed, care must be taken to preserve this vessel to avoid patellar avascular necrosis.

Question 2045

Topic: 3. Adult Reconstruction (Hip & Knee)
Which of the following is the most common cause of failure requiring revision for a medial unicompartmental knee arthroplasty (UKA) at long-term follow-up (>10 years)?
. Periprosthetic joint infection
. Progression of osteoarthritis in the unreplaced compartments
. Periprosthetic tibial fracture
. Patellar maltracking and instability
. Catastrophic wear of the metal components

Correct Answer & Explanation

. Progression of osteoarthritis in the unreplaced compartments

Explanation

While aseptic loosening is a common early-to-midterm reason for UKA revision, at long-term follow-up (>10 years), the progression of osteoarthritis in the unreplaced lateral or patellofemoral compartments is the leading cause of late failure requiring conversion to a total knee arthroplasty.

Question 2046

Topic: 3. Adult Reconstruction (Hip & Knee)

During a primary total knee arthroplasty, the surgeon evaluates the ligamentous tension with trial components in place. The extension gap is found to be excessively tight, while the flexion gap demonstrates appropriate tension and stability. What is the most appropriate surgical step to achieve a balanced knee?

. Resect more distal femur
. Downsize the femoral component
. Release the posterior cruciate ligament
. Recut the proximal tibia with more posterior slope
. Upsize the femoral component

Correct Answer & Explanation

. Resect more distal femur

Explanation

Resecting more distal femur increases the extension gap without altering the flexion gap. This effectively addresses a tight extension / balanced flexion mismatch without destabilizing the knee in flexion.

Question 2047

Topic: 3. Adult Reconstruction (Hip & Knee)

A 68-year-old female presents with a feeling of knee instability particularly when standing up from a chair, 1 year after a posterior-stabilized total knee arthroplasty. Examination reveals stability at 0 degrees and 90 degrees, but marked laxity at 30 to 45 degrees of flexion. What is the most likely surgical cause of this complication?

. Undersizing the femoral component
. Failure to restore the native joint line elevation
. Over-resection of the posterior femoral condyles
. Excessive anterior tibial slope
. Asymmetric medial collateral ligament release

Correct Answer & Explanation

. Failure to restore the native joint line elevation

Explanation

Mid-flexion instability in TKA is most commonly caused by elevation of the joint line. This alters the tension of the collateral ligaments in mid-flexion, causing laxity, even if the knee appears balanced in full extension and 90 degrees of flexion.

Question 2048

Topic: 3. Adult Reconstruction (Hip & Knee)

A 65-year-old female complains of a painful "catching" sensation at the anterior aspect of her knee when extending from 45 degrees to 30 degrees of flexion, one year after undergoing a primary total knee arthroplasty. Which prosthetic design feature is most strongly associated with the development of this specific complication?

. Medial pivot bearing design
. Cruciate-retaining design
. Posterior-stabilized design with a high intercondylar box ratio
. Mobile-bearing unresurfaced patella
. Highly cross-linked polyethylene inserts

Correct Answer & Explanation

. Posterior-stabilized design with a high intercondylar box ratio

Explanation

Patellar clunk syndrome is most commonly associated with older posterior-stabilized TKA designs with a high/sharp intercondylar box. A fibrosynovial nodule forms at the superior pole of the patella and catches in the intercondylar notch during active extension.

Question 2049

Topic: 3. Adult Reconstruction (Hip & Knee)

In revision total knee arthroplasty, an Anderson Orthopaedic Research Institute (AORI) Type 3 bone defect of the proximal tibia is identified. The surgeon decides to use a highly porous tantalum metaphyseal cone. What is the primary biomechanical advantage of utilizing a metaphyseal cone in this setting?

. It shifts the joint line distally to increase the extension gap
. It provides rigid diaphyseal fixation independent of stem use
. It provides immediate mechanical stability and allows for long-term biologic osteointegration
. It eliminates the need for any intramedullary stem extension
. It relies exclusively on polymethylmethacrylate (PMMA) for durable fixation

Correct Answer & Explanation

. It provides immediate mechanical stability and allows for long-term biologic osteointegration

Explanation

Porous metaphyseal cones provide excellent initial mechanical stability through structural support and allow for long-term biologic fixation via osteointegration. This makes them ideal for managing severe cavitary and segmental bone loss (AORI Type 2b and 3).

Question 2050

Topic: 3. Adult Reconstruction (Hip & Knee)

According to the 2018 International Consensus Meeting (ICM) criteria for diagnosing periprosthetic joint infection (PJI), which of the following synovial fluid biomarkers carries the highest weight (points) in establishing a definitive diagnosis?

. Synovial fluid leukocyte esterase
. Synovial fluid polymorphonuclear percentage (PMN%)
. Synovial fluid white blood cell (WBC) count
. Synovial fluid alpha-defensin
. Synovial fluid C-reactive protein (CRP)

Correct Answer & Explanation

. Synovial fluid alpha-defensin

Explanation

Under the 2018 ICM scoring criteria for PJI, a positive synovial fluid alpha-defensin test is highly specific and carries a weight of 3 points. This is equivalent to the combined weight of an elevated synovial WBC count and an elevated PMN percentage.

Question 2051

Topic: 3. Adult Reconstruction (Hip & Knee)

A 60-year-old female with an extensively documented history of severe cutaneous hypersensitivity to cheap jewelry is scheduled for a primary total knee arthroplasty. Patch testing confirms a severe systemic allergy to nickel. Which femoral component material is the most appropriate choice to prevent a delayed hypersensitivity reaction?

. Standard Cobalt-Chromium-Molybdenum alloy
. Oxidized Zirconium
. Uncoated Titanium-Aluminum-Vanadium alloy
. Stainless steel
. Porous Tantalum

Correct Answer & Explanation

. Oxidized Zirconium

Explanation

Standard Cobalt-Chromium alloys contain trace amounts of nickel and can elicit metal hypersensitivity. Oxidized zirconium (Oxinium) components lack nickel while providing excellent wear characteristics, making them ideal for patients with documented severe nickel allergies.

Question 2052

Topic: Total Knee Arthroplasty (TKA)

In calipered kinematic alignment total knee arthroplasty, what is the primary surgical goal regarding the placement of the femoral component?

. Aligning the femoral component strictly perpendicular to the mechanical axis of the femur
. Externally rotating the femoral component exactly 3 degrees off the posterior condylar axis
. Co-aligning the transverse axis of the femoral component with the surgical epicondylar axis
. Restoring the pre-arthritic articular surface by matching the native posterior and distal femoral joint lines
. Maximizing the use of intramedullary guides to dictate the distal femoral resection depth

Correct Answer & Explanation

. Restoring the pre-arthritic articular surface by matching the native posterior and distal femoral joint lines

Explanation

The central tenet of kinematic alignment in TKA is restoring the native, pre-arthritic joint lines and kinematic axes of the knee. This is achieved by removing only the precise thickness of bone and cartilage that corresponds to the thickness of the implant.

Question 2053

Topic: 3. Adult Reconstruction (Hip & Knee)

During the proximal tibial resection in a total knee arthroplasty, the popliteal artery is at risk of iatrogenic injury. At the level of the standard tibial cut, where is the popliteal artery most commonly located in relation to the posterior tibial plateau?

. Medial to the posterior cruciate ligament attachment and 10 mm posterior to the capsule
. Directly posterior to the posterolateral corner structures
. Directly posterior to the posterior horn of the lateral meniscus
. Directly posterior to the posterior cruciate ligament insertion
. Lateral to the fibular head and superficial to the soleus muscle

Correct Answer & Explanation

. Directly posterior to the posterior horn of the lateral meniscus

Explanation

At the level of the standard proximal tibial resection, the popliteal artery runs slightly lateral to the midline. It is located directly posterior to the posterior horn of the lateral meniscus, making it particularly vulnerable during lateral plateau resection.

Question 2054

Topic: 3. Adult Reconstruction (Hip & Knee)

In revision total knee arthroplasty with severe bone loss, anatomic landmarks must be utilized to restore the native joint line. Which of the following relationships is the most reliable anatomic guide for re-establishing the distal femoral joint line?

. 10 mm distal to the adductor tubercle
. 15 mm proximal to the tip of the fibular head
. 25 to 30 mm distal to the medial epicondyle
. 10 mm proximal to the inferior pole of the patella
. Level with the proximal tibiofibular joint

Correct Answer & Explanation

. 25 to 30 mm distal to the medial epicondyle

Explanation

The medial epicondyle is a highly reliable landmark for joint line restoration in revision TKA. The native joint line is consistently located approximately 25 to 30 mm distal to the prominence of the medial epicondyle.

Question 2055

Topic: 3. Adult Reconstruction (Hip & Knee)

During a primary total knee arthroplasty (TKA), the surgeon notes the knee is tight in full extension but symmetrically well-balanced at 90 degrees of flexion. Which of the following is the most appropriate surgical step to correct this mismatch?

. Recut the proximal tibia to increase resection depth
. Decrease the posterior slope of the tibial cut
. Resect additional bone from the distal femur
. Anteriorize the femoral component
. Release the posterior cruciate ligament

Correct Answer & Explanation

. Resect additional bone from the distal femur

Explanation

A tight extension gap with a balanced flexion gap is managed by resecting more bone from the distal femur. Altering the tibial resection depth or slope would incorrectly affect the already balanced flexion gap.

Question 2056

Topic: 3. Adult Reconstruction (Hip & Knee)

During a total knee arthroplasty, trial reduction reveals that the joint is tight in flexion but symmetric and well-balanced in extension. Which of the following is the most likely cause of this mismatch?

. Oversized anteroposterior (AP) femoral component
. Excessive distal femoral resection
. Undersized tibial polyethylene insert
. Excessive posterior tibial slope
. Excessive anterior femoral resection

Correct Answer & Explanation

. Oversized anteroposterior (AP) femoral component

Explanation

An oversized AP femoral component tightens the flexion gap by increasing the posterior femoral offset, without affecting the extension gap. Downsizing the femoral component or increasing posterior tibial slope would help loosen the flexion gap.

Question 2057

Topic: 3. Adult Reconstruction (Hip & Knee)

Which of the following surgical steps during a primary total knee arthroplasty carries the highest risk of iatrogenic injury to the popliteal artery?

. Distal femoral cut
. Anterior chamfer cut
. Proximal tibial cut
. Patellar resection
. Trochlear groove preparation

Correct Answer & Explanation

. Proximal tibial cut

Explanation

The popliteal artery is tethered by the soleus arch just distal to the joint line, making it highly vulnerable during the proximal tibial cut. Proper posterior retractor placement is essential to protect the neurovascular bundle during this step.

Question 2058

Topic: 3. Adult Reconstruction (Hip & Knee)

A 72-year-old patient with severe valgus osteoarthritis presents for a total knee arthroplasty. Intraoperative assessment reveals a completely absent and non-reconstructable medial collateral ligament (MCL). Which level of prosthetic constraint is required?

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

Correct Answer & Explanation

. Rotating hinge knee (RHK)

Explanation

Constrained condylar knee (CCK) implants rely on a competent medial collateral ligament for coronal stability. Complete MCL deficiency or severe global instability requires a rotating hinge prosthesis to prevent catastrophic failure.

Question 2059

Topic: 3. Adult Reconstruction (Hip & Knee)

During a total knee arthroplasty, the tibial component is inadvertently placed in excessive internal rotation. Which of the following clinical consequences is most likely to occur?

. Medial patellar subluxation
. Lateral patellar subluxation
. Global joint stiffness
. Excessive external foot progression
. Femoral component loosening

Correct Answer & Explanation

. Lateral patellar subluxation

Explanation

Internal rotation of the tibial component effectively externalizes the tibial tubercle relative to the trochlear groove, thereby increasing the Q-angle. This typically leads to lateral patellar maltracking and potential subluxation.

Question 2060

Topic: Total Knee Arthroplasty (TKA)

A patient presents with a painful popping sensation at the superior aspect of the patella when extending the knee from a flexed position, 8 months after a primary total knee arthroplasty. This complication is most classically associated with which implant design?

. Cruciate-retaining (CR) TKA
. Posterior-stabilized (PS) TKA
. Constrained condylar knee (CCK) TKA
. Rotating hinge knee (RHK) TKA
. Medial unicompartmental knee arthroplasty (UKA)

Correct Answer & Explanation

. Posterior-stabilized (PS) TKA

Explanation

Patellar clunk syndrome is classically associated with posterior-stabilized (PS) TKA designs. It occurs when a fibrous nodule forms at the superior pole of the patella and catches in the femoral intercondylar box during extension.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page