Hypertrophy of infrapatellar fat pad

**Definition:** This is a hypertrophy of an intracapsular but extrasynovial structure limited by the inferior pole of the patella superiorly, the joint capsule and patellar tendon anteriorly, the proximal tibia and deep infrapatellar bursa inferiorly, and the synovium-lined joint cavity posteriorly. Functionally, the fat pad facilitates joint function by increasing the synovial area and helping to distribute lubricant in the joint. Hypertrophy of the infrapatellar fat pad can lead to pain.