Will I be limited because of painful chondromalacia?

I am a 13 year old extreme athlete and about 6 monts ago I noticed a little pain in my knee. Now it's at the point where walking is painful. I don't want to give up my workout regimen but it's hard to do it. My podiatrist diagnosed chondromalacia but my P. T said that he didn't think that was it. I am seeing a podiatrist because of my painful flat feet. I have three questions: When would arthroscopic surgery be required? Who should I believe? Will I need to stop my activities and use crutches to rest it or what? Any info is greatly appreciated! Thanks!

First see an orthopedist. Flat feet can cause chondromalacia. They may also cause shin splints, subluxing patella, patellar tendinitis, or osgood schalater disease.
Second, don't even think about surgeyr until you get a diagnosis. Most likely this is an overuse injury. With an overuse injury you need to correct the improper biomechanics. If it is chondromalacia a solid knee brace to help realign the patella will help. Again, you should not listen to either the PT or the Podiatrist. Go see an orthopedist. They will determine the next course of action. Possibly an MRI.

Keep going to physical therapy and ask all of these questions of the therapist. Condromalacia is not a terribly specific diagnosis (I believe it means "pain in the joint") so your PT will probably develop a more specific idea of what contributed to your condition and how to treat it.

Ask the PT what sort of physical activities are least likely to cause you knee pain. You'll need to adapt, at least until you're out of pain. You might be able to swim or to use an upper body ergometer. Use the injury as a way of learning about your body, how to use it more efficiently, and how to use other parts of it to get a workout.

I was a professional dancer and I experienced many injuries during my career, including condromalacia. I've worked with a great many physical therapists, and learned an enormous amount in the process.

Chondromalacia is a cartlidge problem on the inside of your kneecap. Usually your knee glides back & forth. If the cartlidge inside becomes rough, it catches & causes pain. I know. My son had arthroscopy surgery to remove the pieces. Sometimes pieces come loose & float inside the joint, which is also painful. My sons knee ached, was quite painful sometimes. Other times it would catch, lock or give away. You should go see an Orthopedic Specialist to confirm.