Which of the following bones forms the knee joint along with the femur and tibia?

The patella, also known as the kneecap, plays a crucial role in the formation of the knee joint alongside the femur and tibia. The patella is a sesamoid bone located in the quadriceps tendon and acts to increase the leverage of the quadriceps muscle during knee extension. It provides protection to the knee joint and enhances the overall stability and efficiency of movement. The patella fits into a groove at the lower end of the femur, allowing for smooth motion and a more effective mechanical function.

In contrast to the patella, the fibula is a bone that runs parallel to the tibia but is not directly involved in the knee joint's articulation. The maxillae and mandible are bones of the facial skeleton and have no anatomical relevance to the knee joint. Thus, the patella is the only bone listed that correctly complements the femur and tibia in forming the knee joint.