Infrapatellar fat pad

The infrapatellar fat pad, also known as Hoffa's fat pad, is a cylindrical piece of fat that is situated under and behind the patella bone within the knee.

Potential Problems

The fat pad is a normal structure but it can sometimes become a problem:

-It can become damaged and painful
-It can be deliberately removed at arthroscopic surgery to make it easier for the surgeon to see what they are doing - but this can also lead to scarring and pain.
-It can get very big (hypertrophy) and may become nipped (’impingement’) between the patella and the femoral condyle, causing sharp pain when the leg is extended.
-It can become involved in the process of arthrofibrosis and become scarred (fibrotic) and contracted, pulling the patella down into an abnormally low position.

Sources

• The KNEEguru - educational site packed with knee content with sections on the infrapatellar fat pad