Ducts

A synovial duct is a structure similar to a pulley, which envelops the tendon in part, and which secretes a fluid to prevent friction and to guide the tendon in its activity of bending or extension. Some pathologies (Dupuytren’s contracture) thicken tendons or ducts, and occasionally, these will be cut to release the tendon and allow it to perform its normal movement (e.g. trigger finger pathology).