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Knee Sports MCQs

Practice Set 23 of 102

This practice set contains high-yield board review questions covering key concepts in Knee Sports. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 441

Topic: Knee Sports
During medial patellofemoral ligament (MPFL) reconstruction, identifying the anatomical femoral attachment is critical to avoid graft anisometry. Where is the normal femoral origin of the MPFL located?
. Anterior to the medial epicondyle and distal to the adductor tubercle
. Posterior to the medial epicondyle and proximal to the adductor tubercle
. Between the medial epicondyle and the adductor tubercle
. Distal to the medial collateral ligament origin
. Directly on the gastrocnemius tubercle

Correct Answer & Explanation

. Between the medial epicondyle and the adductor tubercle

Explanation

The MPFL originates in a saddle-like groove situated between the medial epicondyle and the adductor tubercle on the medial femur (Schöttle's point). Non-anatomic femoral tunnel placement is a primary cause of postoperative MPFL graft failure.

Question 442

Topic: Knee Sports

A 21-year-old female presents with recurrent lateral patellar instability. Imaging demonstrates a tibial tubercle-trochlear groove (TT-TG) distance of 24 mm and a Caton-Deschamps index of 1.0. Trochlear depth is normal. What is the most appropriate surgical intervention?

. Isolated MPFL reconstruction
. MPFL reconstruction with medializing tibial tubercle osteotomy
. MPFL reconstruction with distalizing tibial tubercle osteotomy
. Sulcus-deepening trochleoplasty
. Lateral retinacular release

Correct Answer & Explanation

. MPFL reconstruction with medializing tibial tubercle osteotomy

Explanation

A TT-TG distance > 20 mm is an indication for a medializing tibial tubercle osteotomy (Fulkerson procedure) to correct the abnormal lateral extensor mechanism vector. MPFL reconstruction is performed concurrently to restore the torn primary medial soft-tissue restraint.

Question 443

Topic: Knee Sports

The medial patellofemoral ligament (MPFL) provides the primary soft-tissue restraint to lateral patellar translation at which of the following knee flexion angles?

. 0 to 30 degrees
. 45 to 60 degrees
. 60 to 90 degrees
. 90 to 120 degrees
. Beyond 120 degrees

Correct Answer & Explanation

. 0 to 30 degrees

Explanation

The MPFL is the primary restraint to lateral patellar translation in early flexion (0 to 30 degrees). Beyond 30 degrees of flexion, the patella engages the trochlea, and the bony architecture becomes the primary stabilizer.

Question 444

Topic: Knee Sports

A lateral radiograph of the knee in a patient with patellar instability demonstrates a "crossing sign" and a "supratrochlear spur", but no "double contour" sign. According to the Dejour classification, what type of trochlear dysplasia does this represent?

. Type A
. Type B
. Type C
. Type D
. Type E

Correct Answer & Explanation

. Type B

Explanation

Dejour Type B trochlear dysplasia is characterized by a flat trochlea, presenting as a "crossing sign" and a "supratrochlear spur" on a true lateral radiograph. Type C exhibits a crossing sign and double contour, while Type D has all three signs.

Question 445

Topic: Knee Sports

During a medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar instability, the surgeon must be careful when tensioning the graft. Which of the following describes the optimal position and tensioning technique to avoid iatrogenic complications?

. Tensioning the graft in full extension to prevent terminal lateral subluxation
. Tensioning the graft in 90 degrees of flexion to ensure maximum stability
. Tensioning the graft in 20 to 30 degrees of flexion with the patella centralized
. Over-tensioning the graft in 60 degrees of flexion to compensate for future stretching
. Tensioning the graft in full extension with a lateral stabilizing force applied

Correct Answer & Explanation

. Tensioning the graft in 20 to 30 degrees of flexion with the patella centralized

Explanation

The MPFL provides maximum restraint to lateral patellar translation at 0 to 30 degrees of flexion. The graft should be tensioned at 20-30 degrees of flexion just enough to restore normal tracking; over-tensioning leads to medial cartilage overload and loss of knee flexion.

Question 446

Topic: Knee Sports

A 22-year-old female presents with recurrent patellar dislocations. Advanced imaging reveals a tibial tubercle-trochlear groove (TT-TG) distance of 24 mm and a normal Caton-Deschamps index. Which of the following surgical interventions is MOST appropriate?

. Isolated Medial Patellofemoral Ligament (MPFL) reconstruction
. Lateral retinacular release
. Anteromedial tibial tubercle osteotomy (Fulkerson procedure)
. Medial tibial tubercle transfer and MPFL reconstruction
. Distalization of the tibial tubercle

Correct Answer & Explanation

. Medial tibial tubercle transfer and MPFL reconstruction

Explanation

A TT-TG distance > 20 mm is a primary indication for a medializing tibial tubercle osteotomy to correct the lateralized extensor mechanism. It is typically combined with MPFL reconstruction to restore the primary medial soft-tissue restraint.

Question 447

Topic: Knee Sports

A 45-year-old active male with medial compartment knee osteoarthritis and genu varum undergoes a medial opening wedge high tibial osteotomy (HTO). Which of the following is a common biomechanical consequence if the posterior gap is not appropriately larger than the anterior gap?

. Increase in posterior tibial slope, which increases tension on the Anterior Cruciate Ligament (ACL)
. Decrease in posterior tibial slope, which increases tension on the Posterior Cruciate Ligament (PCL)
. Patella baja due to significant distalization of the tibial tubercle
. Excessive internal rotation of the distal tibial segment
. Medialization of the mechanical axis beyond the lateral tibial spine

Correct Answer & Explanation

. Increase in posterior tibial slope, which increases tension on the Anterior Cruciate Ligament (ACL)

Explanation

In a medial opening wedge HTO, the posterior tibial cortex is naturally wider than the anterior cortex. Failing to open the posterior gap more than the anterior gap (typically a 2:1 ratio) inadvertently increases the posterior tibial slope, increasing strain on the ACL.

Question 448

Topic: Knee Sports

When evaluating a patient with recurrent patellar instability, a lateral radiograph demonstrates the "crossing sign" and a "supratrochlear spur." According to the Dejour classification for trochlear dysplasia, which type does this represent?

. Type A
. Type B
. Type C
. Type D
. Type E

Correct Answer & Explanation

. Type B

Explanation

In the Dejour classification of trochlear dysplasia, Type B is characterized by a flat trochlea, the presence of a "crossing sign" (the trochlear floor crosses the anterior border of the condyles), and a supratrochlear spur.

Question 449

Topic: Knee Sports
An orthopaedic surgeon is identifying the femoral footprint of the medial patellofemoral ligament (MPFL) using fluoroscopy (Schöttle's point). Anatomically, where is the MPFL attachment located relative to the local bony landmarks?
. Anterior to the adductor tubercle and proximal to the medial epicondyle
. In the saddle area distal to the adductor tubercle and proximal/posterior to the medial epicondyle
. Distal to the medial epicondyle and anterior to the medial collateral ligament (MCL) origin
. Directly on the medial epicondyle, blending with the superficial MCL
. Proximal to the adductor tubercle along the medial supracondylar ridge

Correct Answer & Explanation

. In the saddle area distal to the adductor tubercle and proximal/posterior to the medial epicondyle

Explanation

The anatomic femoral origin of the MPFL lies in a small saddle or groove situated slightly distal to the adductor tubercle and proximal/posterior to the medial epicondyle.

Question 450

Topic: Knee Sports

During the physical examination of a patient with anterior knee pain and instability, the examiner observes a positive "J-sign." What is the pathomechanics underlying this clinical finding?

. The patella suddenly translates medially as the knee is flexed past 30 degrees.
. The patella translates laterally in terminal knee extension as it exits the trochlear groove.
. The patella subluxates posteriorly when a posterior force is applied to the proximal tibia.
. The patella completely dislocates laterally when the knee is maintained in 90 degrees of flexion.
. The patella clicks superiorly due to a tight patellar tendon during active extension.

Correct Answer & Explanation

. The patella translates laterally in terminal knee extension as it exits the trochlear groove.

Explanation

The J-sign describes the sudden lateral deviation (in an inverted 'J' shape) of the patella during terminal knee extension. It occurs because the patella loses the bony restraint of the trochlear groove, often exacerbated by patella alta or excessive TT-TG distance.

Question 451

Topic: Knee Sports
During a medial patellofemoral ligament (MPFL) reconstruction, identifying the correct femoral attachment is critical to prevent graft anisometry. According to Schöttle's point, where is the anatomic femoral origin of the MPFL located?
. Anterior and distal to the medial epicondyle
. Proximal and posterior to the medial epicondyle, and distal to the adductor tubercle
. Distal to the medial epicondyle and anterior to the adductor tubercle
. Directly on the tip of the adductor tubercle
. Proximal and anterior to the adductor tubercle

Correct Answer & Explanation

. Proximal and posterior to the medial epicondyle, and distal to the adductor tubercle

Explanation

The MPFL femoral footprint is located within a saddle-like sulcus posterior and proximal to the medial epicondyle, and distal to the adductor tubercle. Schöttle's point radiographically defines this origin just anterior to the posterior femoral cortex line and distal to Blumensaat's line.

Question 452

Topic: Knee Sports

In evaluating a patient with recurrent patellar dislocations, a computed tomography (CT) scan is obtained. At what tibial tubercle-trochlear groove (TT-TG) distance is a tibial tubercle medialization osteotomy generally considered an absolute indication when treating patellar instability?

. Greater than 10 mm
. Greater than 15 mm
. Greater than 20 mm
. Greater than 25 mm
. Greater than 30 mm

Correct Answer & Explanation

. Greater than 20 mm

Explanation

A TT-TG distance > 20 mm is considered pathologic and represents an indication for a medializing tibial tubercle osteotomy (e.g., Elmslie-Trillat or Fulkerson) in the setting of recurrent patellar instability. Normal values are typically 9-13 mm.

Question 453

Topic: Knee Sports

A true lateral radiograph of the knee in a patient with patellar instability demonstrates a "crossing sign" and a prominent "supratrochlear spur," but no double contour sign. According to the Dejour classification of trochlear dysplasia, what type does this represent?

. Type A
. Type B
. Type C
. Type D
. Type E

Correct Answer & Explanation

. Type B

Explanation

Dejour Type B dysplasia is characterized by a flat trochlea, marked radiographically by a crossing sign and a supratrochlear spur. Type A has a shallow groove (crossing sign only), Type C has a convex lateral facet (crossing sign + double contour), and Type D has a cliff pattern.

Question 454

Topic: Knee Sports

When performing an isolated medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar instability, at what knee flexion angle and tension should the graft be fixed to the femur to prevent medial patellar overload?

. Full extension with 10 N tension
. 30 degrees of flexion with minimal tension to restore normal patellar glide
. 60 degrees of flexion with tight tension
. 90 degrees of flexion with 20 N tension
. Full extension with maximum manual tension

Correct Answer & Explanation

. 30 degrees of flexion with minimal tension to restore normal patellar glide

Explanation

MPFL grafts should be fixed at approximately 30 degrees of knee flexion with minimal tension (just enough to eliminate slack). Over-tensioning can lead to medial patellofemoral compartment overload, anterior knee pain, and restricted flexion.

Question 455

Topic: Knee Sports

A 22-year-old female presents with recurrent patellar instability. MRI demonstrates a tibial tubercle-trochlear groove (TT-TG) distance of 24 mm and a Caton-Deschamps index of 1.1. No significant trochlear dysplasia is noted. What is the most appropriate surgical intervention?

. Isolated MPFL reconstruction
. MPFL reconstruction with tibial tubercle anteromedialization
. Lateral retinacular release
. MPFL reconstruction with tibial tubercle distalization
. Sulcus-deepening trochleoplasty

Correct Answer & Explanation

. MPFL reconstruction with tibial tubercle anteromedialization

Explanation

A TT-TG distance greater than 20 mm is a standard indication for a medializing tibial tubercle osteotomy (TTO). Combined anteromedialization (Fulkerson osteotomy) addresses the lateralized vector and unloads the patellofemoral joint, typically coupled with an MPFL reconstruction.

Question 456

Topic: Knee Sports

A 10-year-old skeletally immature female with open physes requires surgical stabilization for recurrent patellar dislocations. To minimize the risk of iatrogenic growth arrest, the femoral attachment of an MPFL reconstruction should ideally be placed in relation to the distal femoral physis in which location?

. Directly on the physis
. Distal to the physis
. Proximal to the physis
. On the lateral condyle
. The MPFL cannot be reconstructed in skeletally immature patients

Correct Answer & Explanation

. Distal to the physis

Explanation

In skeletally immature patients, the anatomic femoral origin of the MPFL is typically located just distal to the distal femoral physis. Care must be taken to utilize soft tissue techniques or place fixation distal to the growth plate to prevent angular deformity or growth arrest.

Question 457

Topic: Knee Sports

During an anatomic medial patellofemoral ligament (MPFL) reconstruction, identifying the correct femoral footprint is critical. Radiographically, Schottle's point represents this attachment. What are the landmarks for Schottle's point on a true lateral radiograph?

. Anterior to the posterior femoral cortical line, proximal to Blumensaat's line
. Posterior to the posterior femoral cortical line, distal to Blumensaat's line
. Anterior to the posterior femoral cortical line, distal to Blumensaat's line
. 1 mm anterior to the posterior femoral cortical line, 2.5 mm distal to the posterior border of Blumensaat's line
. 1 mm anterior to the posterior femoral cortical line, 2.5 mm proximal to the posterior border of Blumensaat's line

Correct Answer & Explanation

. 1 mm anterior to the posterior femoral cortical line, 2.5 mm proximal to the posterior border of Blumensaat's line

Explanation

Schottle's point is located 1 mm anterior to the posterior femoral cortical line and 2.5 mm proximal to the posterior border of Blumensaat's line. It serves as a reliable and reproducible radiographic landmark for the anatomic femoral origin of the MPFL.

Question 458

Topic: Knee Sports

Following the diagnosis of aseptic loosening, the candidate expresses concern about the state of the collateral ligaments, particularly the MCL, and the extensive bone loss. The patient is planned for revision surgery.

. PCL Retaining (CR)
. PCL Substituting (PS)
. Unlinked Constrained Condylar (VVC)
. Linked, Constrained Condylar (RHK)
. Rotating Platform (RP)

Correct Answer & Explanation

. Unlinked Constrained Condylar (VVC)

Explanation

Correct Answer: CThe case explicitly states, "The collateral ligaments are likely to be dysfunctional and especially the MCL therefore a constrained knee replacement may be required." The constraint ladder for knee implants progresses from PCL retaining (CR) to PCL substituting (PS), then to unlinked constrained condylar (VVC), and finally to linked, constrained condylar (RHK). A VVC implant, such as an LCCK or TC3, is specifically designed to provide anteroposterior and varus-valgus stability, substituting for deficient collateral ligaments. While an RHK (Linked, Constrained Condylar) is used for global instability or severe bone loss/fracture, the primary concern highlighted is dysfunctional collateral ligaments, making VVC the most appropriate initial step up in constraint for this specific issue. CR and PS designs do not adequately address significant collateral ligament insufficiency.

Question 459

Topic: Knee Sports

The examiner asks about the advantages of PCL substituting (PS) over PCL retaining (CR) designs.

. Requires less bone resection, preserving more bone stock.
. Offers a more natural kinematic motion due to PCL preservation.
. Provides a degree of varus-valgus constraint and improved anterior-posterior stability via the cam-post mechanism.
. Has a lower risk of patellofemoral complications.
. Is technically more challenging, requiring specialized surgical expertise.

Correct Answer & Explanation

. Provides a degree of varus-valgus constraint and improved anterior-posterior stability via the cam-post mechanism.

Explanation

Correct Answer: CThe case explicitly lists several advantages of PCL substituting (PS) designs over PCL retaining (CR) designs. These include: conforming surfaces allowing roll-back, no component slide, providing a degree of VVC (varus-valgus constraint), and the cam-post mechanism improving anterior-posterior stability. PS designs also facilitate deformity correction, use more congruent joint surfaces (reducing wear), offer better range of motion, and are often considered technically easier and more reproducible. Options A and B are generally associated with CR designs (PCL preservation potentially leading to less bone resection and more natural kinematics), while options D and E are not recognized advantages of PS designs; in fact, PS designs can sometimes have specific patellofemoral issues related to the box cut, and are generally considered technically simpler than CR in terms of balancing.

Question 460

Topic: Knee Sports

A 68-year-old patient with a history of rheumatoid arthritis presents with a progressive, painful knee flexion deformity. Radiographs show normal bony alignment with a PDFA of 83° and a PPTA of 81°. Clinically, the patient has a fixed 25-degree flexion contracture. Which of the following structures is most likely contributing to this patient's inability to achieve full knee extension?

. Anterior cruciate ligament
. Patellar tendon
. Posterior joint capsule and hamstring tendons
. Quadriceps femoris muscle
. Medial collateral ligament

Correct Answer & Explanation

. Posterior joint capsule and hamstring tendons

Explanation

Correct Answer: CThe case clearly distinguishes between bony deformity and soft tissue contracture. The patient's normal PDFA (83°) and PPTA (81°) indicate normal bony geometry, ruling out a procurvatum deformity. Therefore, the 25-degree fixed flexion contracture is due to a soft tissue restriction. The text specifically identifies the posterior structures of the knee—theposterior joint capsule, the hamstring tendons (semitendinosus, semimembranosus, biceps femoris), and the origins of the medial and lateral gastrocnemius heads—as becoming shortened, fibrotic, and non-compliant, acting as a rigid tether that blocks extension. This is frequently seen in inflammatory arthropathies like rheumatoid arthritis.Option A (Anterior cruciate ligament) is incorrect. The ACL primarily prevents anterior translation of the tibia and rotational instability; it does not directly restrict knee extension in a fixed flexion deformity.Option B (Patellar tendon) is incorrect. The patellar tendon connects the patella to the tibial tubercle and is involved in quadriceps function, but its shortening is not a primary cause of fixed knee flexion deformity. Patella alta (high-riding patella) can be associated with crouch gait, but the tendon itself doesn't cause the flexion contracture.Option D (Quadriceps femoris muscle) is incorrect. The quadriceps are the primary extensors of the knee. In FFD, they are often overstretched and fatigued, not contracted in a way that prevents extension. Their weakness or inability to overcome the flexion moment is a consequence, not a cause, of the FFD.Option E (Medial collateral ligament) is incorrect. The MCL provides valgus stability to the knee and does not primarily restrict sagittal plane extension.

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