There may also be a snapping sensation as the knee is bent. This is due to the rubbing of the thickened plica over the round edge of the medial femoral condyle. There is usually tenderness over the area where the plica is located. In thin people, the tissue that forms the plica may be actually be felt as a tender band underneath the skin. If the irritation from the plica is particularly bad, there may be swelling in the entire knee.
Diagnosis begins with a history and physical .
The examination will try to determine where the pain is located and whether or not the band of tissue can be felt. X-rays will not show a plica. X-rays are mainly useful to determine if other conditions are present if there is not a clear cut diagnosis. If there is a uncertainty in the diagnosis following the history and physical examination, or if other injuries in addition to the plica syndrome are suspected, a MRI scan may be suggested. Usually, this test is done to look for injuries, such as tears in the menisci or ligaments of the knee.