Which structure separates the patellar tendon from the joint capsule?

The infrapatellar fat pad plays a crucial role in the knee joint's anatomy by serving as a cushion that separates the patellar tendon from the joint capsule. This fatty tissue not only provides cushioning and protection for the underlying structures but also helps reduce friction during knee movements, allowing for smoother articulation between the tendon and surrounding tissues. By acting as a buffer, the infrapatellar fat pad is significant in maintaining joint integrity and facilitating movement.

In contrast, other structures listed are anatomy-related but do not serve this specific function of separating the patellar tendon from the joint capsule. While the suprapatellar bursa is located superior to the patella, the deep infrapatellar bursa is found underneath the patellar tendon but does not create the separation from the joint capsule itself. The prepatellar bursa, located over the kneecap, provides a different protective mechanism but is not involved in the separation of the tendon from the capsule. Thus, the infrapatellar fat pad is the primary structure that fulfills the role of separation in this context.