Question

A. How is the patella stabilized? Describe the articulation of the patella with the femur.

B. How does knee joint angle effect compressive forces at the patella and the contact points of the patella on the femur?

C. Which ligaments are intra-articular and which are extra-articular in the knee?

Answer 1

A. Quadriceps ie, the thigh muscles helps k to keep the patella stable and in place.

The patella articulates with the patellar surface of the femur which prevents rubbing of the muscle tendon against the distal femur.

B. The compression forces of the patellofemoral joint is generally influenced by the quadriceps muscle force and the knee flexion angle.The patella acts like a pulley with quadriceps tendon by attaching to it proximally and the patellar tendon attaching to it distally by transmitting the forces of the knee extensor mechanism and thus the  resultant of the Quadriceps tendon and patellar tendon forces is directed to the intercondylar groove. Generally, the compression force in the patellofemoral joint increases with increasing knee flexion.

C. The intra-articular ligaments are the posterior cruciate ligament, anterior cruciate ligament and posterior meniscofemoral ligament While extra-articular ligaments are medial collateral ligament and lateral collateral ligament.

Hope this helps you. Thank you ?