Signs of getting old?

Well, my knee issue seems to be getting a little worse. Today my left knee felt a little fatigued after my 30 mile trainer session last night and the clicking is still audible. I did some sleuthing around on the net and found some interesting possibilities on my geriatric situation.

What is plica syndrome in athletes? 

Plica syndrome is often characterized by anterior knee pain, which is most commonly found along the superomedial aspect of the knee. The “plica” is due to remnant embryological tissue that compartmentalizes the knee during fetal development. The plica is considered a “vestigial” structure, which means that it has lost its ability to function over time and does not functionally affect an individual whether it is present or absent. It has been likened to the appendix, which can be a source of pain but lacks significant important function.

Dont know for sure, but this seems to be it. I guess a doctors visit is in order.