Abstract
Synvisc (hylan G-F 20) is a high molecular weight hyaluronan which is manufactured from chicken combs. It is currently one of the options used in the treatment of severe osteoarthritis of the knee joint. Synvisc is directly injected into the diseased joint, where it provides elasticity and viscosity. Published experience suggests than Synvisc is a safe and well-tolerated material with occasional mild local reactions but no long-term adverse sequelae. This article describes a case of Synvisc-related granulomatous inflammation in the perisynovial adipose tissue. To our knowledge, this is the first histological account of tissue reaction to Synvisc.