Can arthritis tear your knee cartilage?

Unfortunately, yes.

Depending on where the tear is on your meniscus, it may heal by itself or you may need to have surgery.

Healing by itself will reduce the likelihood of Arthritis but surgery is different. If the tear is small but not receiving blood flow, your doctor may suggest leaving it be or shaving the cartilage down to reduce the chance of more tearing (this was the case in my situation). If the tear is large, you may need to have your meniscus replaced instead. Whether you let it be, shave it down, or get it replaced, there is a chance of arthritis. The way to look at it is whether or not you are suffering from the damaged meniscus now. If you are, your doctor would likely recommend undergoing surgery to improve your quality of life and deal with the possibility of arthritis later because there is no guarantee that you won't have it when you get older anyways if you left it alone.

In any case, the best option would be to speak to your doctor about it. He or she will be able to answer any further questions you have an guide you in the right direction.