This is an old thread, but to answer Nikiib, it can be treated.
First, the ligaments are stretched and/or torn. You have to lessen the pressure on them when you run. The problem is that your kneecap isn't tracking properly.
You are probably pronating. Let me explain. Shortly after your heel hits, the forefoot slams down. The impact force of the forefoot striking is even harder than the heel and it happens very fast. The result is the arch collapses. In turn, the ankle rocks inward and the knee torques inward. This twisting of the knee is a major cause of chondromalacia. If you resolve the pronation, the knee will track more or less properly.
The solution is to eliminate pronation AND lessen the speed of your forefoot impact.
Motion control and stability shoes are not the answer. You need orthotics to correct your particular level of pronation. You can make your own. I do and I've described the process here on LetsRun.
You also need to convert from heel to forefoot strike. Surprisingly, landing on the forefoot slows the impact speed and thus lessens the collapse of the arch. Again, I've done this. Again, it's too long to explain here.
I could not run more than two miles without pain. Then, around 1992, I discovered ChoPat knee straps to help my kneecap track properly. They worked and I ran in them for nearly ten years. Then, to get faster in the mid-distances, I converted to forefoot strike. When I did, the knee problems went away. I describe all this in my book.