Hoffa's test is a clinical test for a damaged or irritated infrapatellar (Hoffa) fat pad in the area behind the patellar tendon.
Side view of the knee joint, showing the situation of the Hoffa fat pad in the space behind the patellar tendon.
Position of the thumbs when performing the Hoffa's test.
How to perform Hoffa's Test
With the patient lying on the coach, and the examiner standing by the patient's knee, the examiner takes up the bent knee, pressing the thumbs of both hands deeply along the sides of the patellar tendon just below the patella. The patient is then instructed to straighten the leg. If there is inflammation of the fat pad, this causes pain in the fat pad region.
What does the Hoffa fat pad do?
The infrapatellar or Hoffa fat pad acts as a flexible cushion within the knee joint inside the capsule where it cushions the important structures of the front of the knee. It contains blood vessels and nerves and is covered by the same layer of cells (synovium) that lines the rest of the capsule and which provides lubrication for the joint. It is intimately related anatomically to the ligamentum mucosum (infrapatellar plica).
Evaluation and treatment of disorders of the infrapatellar fat pad. Dragoo JL, Johnson C, McConnell J. Sports Med. 2012 Jan 1;42(1):51-67. doi: 10.2165/11595680-000000000-00000.
A large infrapatellar fat pad protects against knee pain and lateral tibial cartilage volume loss. Teichtahl AJ, Wulidasari E, Brady SRE, Wang Y, Wluka AE, Ding C, Giles GG and Cicuttini FM. Arthritis Res Ther. 2015; 17: 318.