Hoffa's syndrome is pain in the front of the knee associated with irritation or scarring of the infrapatellar fat pad (Hoffa fat pad).
Inflammation of the Hoffa fat pad
The Hoffa fat pad cushions and protects the menisci and cruciate ligaments, but is itself vulnerable to injury from accidents and also from the portals that the knee surgeon creates during keyhole surgery. Bleeding and scarring in the fat pad can cause pain in the front of the knee.
Posterior Hoffa’s fat pad impingement secondary to a thickened infrapatellar plica: a case report and review of the literature. Radu A, Discepola F, Volesky M, Munk PL and Le H. J Radiol Case Rep. 2015 Mar; 9(3): 20–26.