Embryology
Plica are remnants of the partition of the embryological knee. Normally, there are thickenings within the synovial layer of the knee.

Symptoms
Intra-articular plicae are a cause of clicking symptoms when bending the knee

Diagnosis
They cause pain and swelling in the front of the knee. They can be felt as a band of tissue running across the inner side of the knee. They produce a clicking noise when the knee is bent

Treatment
I diagnose and treat symptomatic plicae of the knee by  knee arthroscopy. The band is excised arthroscopically.