Plica is Latin for fold. The knee is enclosed by a large envelope of tissue. This tissue can form folds. Some happen with growth; some happen after injury.

These plicae can rub against the bones in the knee and cause discomfort and snapping, especially in the 10–16-year-old with no knee injury. Unfortunately, they don’t show up well on x-rays or MRI. Therefore, the diagnosis is usually made by history and physical exam.

I have several young patients that have done well after removal of plica by knee arthroscopy.

Walker Wynkoop MD a resident of Los Banos, and a Board-Certified Orthopedic Surgeon with 30 years of experience. He works at Surgical Affiliates of California. His email is