Question

What role does the Patella play in the patellofemoral joint complex and why is it important?

Answer 1

The patellofemoral joint is a diarthrodial plane joint that consists of the posterior surface of the patella and the trochlear surface of the distal anterior femur. The patella is the largest sesamoid bone in the body.

The patella lies within the quadriceps tendon and thereby increases the mechanical advantage of the quadriceps mechanism. Not only does the patella increase the force of knee extension by 50%, but it also provides stability to the patellar tendon and minimizes the forces placed on the femoral condyles.

The patella functions primarily as an anatomic pulley for the quadriceps muscle. Interposing the patella between the quadriceps tendon and the femoral condyles also reduces friction as the femoral condyles contact the hyaline cartilage-covered posterior surface of the patella rather than the quadriceps tendon.

Importance of Patella :

Function. The primary functional role of the patella is knee extension. The patella increases the leverage that the quadriceps tendon can exert on the femur by increasing the angle at which it acts. The patella is attached to the tendon of the quadriceps femoris muscle, which contracts to extend/straighten the knee.