title: Inflammation of the infrapatellar fat pad.
abstract: The infrapatellar fat pad (IFP) of Hoffa's fat pad is the main adipose structure within the knee joint. It is located between the joint capsule and the synovial membrane, which lines its posterior aspect. The IFP is composed chiefly of adipocytes and receives an abundant supply of blood vessels and nerves. Immune cells can infiltrate the IFP, which can become a major source of numerous proinflammatory mediators (cytokines and adipokines). The physiological role for the IFP remains unclear but may involve shock absorption and the protection of adjacent tissues. Hoffa's disease is characterized by inflammation, hypertrophy, and fibrosis of the pad in response to repetitive trauma. Anterior knee pain is the most common symptom. In advanced forms, metaplasia of the IFP may result in the development of a sometimes sizable osteochondroma. The IFP may also contribute to the pathophysiology of knee osteoarthritis, in particular via procatabolic and proinflammatory effects on its synovial lining. Finally, in patients with knee osteoarthritis, inflammation of the IFP may be a source of pain.
authors.affiliation: Service de rhumatologie, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94000 Créteil, France. Electronic address: florent.eymard@hmn.aphp.fr.
authors.forename: Florent
authors.initials: F
authors.lastname: Eymard
authors.affiliation: Service de rhumatologie, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94000 Créteil, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Chevalier
mesh_terms: D000273:Adipose Tissue / Q000503:physiopathology*; D018771:Arthralgia / Q000000981:diagnostic imaging / Q000453:epidemiology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D007719:Knee Joint / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D010147:Pain Measurement; D010329:Patella / Q000503:physiopathology*; D011379:Prognosis; D018570:Risk Assessment
keywords: Adipokines; Hoffa's disease; Inflammation; Infrapatellar fat pad; Knee osteoarthritis