The word 'syndrome' means a group of clinical findings that tend to be associated with one another, and likely to have a common cause.
The plica syndrome is a group of clinical findings in the knee which appear to be related to damage to a rather enigmatic structure called the synovial plica.
The inner walls of the knee joint are lined with a special tissue called the synovium, the cells of which secrete the fluid that lubricates the joint. In many people, but not all, a thin sheet of synovium may stretch from the wall across to the more central structures and this would be called a synovial plica.
