Advanced Patella Quiz

Q1. Why does the patella improve the mechanical advantage of the quadriceps?

• It increases the extensor moment arm of the quadriceps mechanism
• It locks the hip joint during extension
• It shortens the quadriceps moment arm to zero
• It transfers quadriceps force directly to the fibula

Q2. Why is lateral patellar dislocation more common than medial dislocation?

• The patellar ligament normally pulls strongly medially
• The patella has no medial stabilizing structures
• Patellar tracking forces commonly favor lateral displacement when medial restraints fail
• The fibula pushes the patella medially during flexion

Q3. How does trochlear engagement change patellar stability during early knee flexion?

• The tibial plateau becomes the primary patellar articulation
• The patella becomes completely detached from the femur
• Bony stability increases as the patella enters the trochlear groove
• Trochlear engagement disappears with flexion

Q4. Why can a transverse patellar fracture disrupt active knee extension?

• It severs the Achilles tendon
• It disrupts the hip abductors
• It isolates the fibular head
• It can interrupt continuity of the knee extensor mechanism

Q5. Why can patellar fractures threaten the articular surface even when the extensor mechanism remains intact?

• They can produce patellofemoral articular incongruity and cartilage injury
• Only the tibial plateau determines patellofemoral mechanics
• The posterior patella is entirely nonarticular
• The patella never contacts the femur

Q6. What is the main source pattern of arterial supply around the patella?

• A single terminal branch of the dorsalis pedis artery
• Only the posterior tibial artery at the ankle
• Only the obturator artery
• A periarticular genicular anastomotic network

Q7. Why can patella alta contribute to instability?

• It eliminates the quadriceps tendon
• It moves the patella into the popliteal fossa
• It delays engagement of the patella with the trochlear groove
• It permanently fuses the patella to the femur

Q8. Why can patella baja alter knee mechanics?

• It alters extensor mechanism geometry and patellofemoral contact
• It converts the patella into a nonarticular bone
• It moves the patella above the quadriceps tendon
• It prevents the femur from articulating with the tibia

Q9. How does patellar contact with the femur generally change as the knee flexes from extension?

• The location and area of patellofemoral contact change progressively with flexion
• Only the patellar apex contacts the femur at every angle
• The patella loses all femoral contact throughout flexion
• The patella begins articulating with the fibula

Q10. Which statement best integrates the anatomy of the patella?

• It is a pelvic bone that forms the acetabulum
• It is a sesamoid component of the extensor mechanism that improves leverage and participates in patellofemoral tracking, stability, and load transmission
• It is a posterior knee bone embedded in the hamstring tendons
• It is a tarsal bone that stabilizes the ankle mortise