You should always consult a dr about this stuff if you can because it's a case by case issue. Knee braces are super helpful for skiing with bad knees, especially if you actually have an injury. However, you shouldn't become reliant on them (unless a Dr says otherwise obviously) because of stress shielding. Stress shielding is where your body gets used to some forces being diverted around your bones and over time, your bone starts to become less dense and strong. This obviously can lead to future problems, so if you just feel some pain, but don't actually have an injury to nurse, you should try to manage without a brace, it's probably better in the long run. Again, every person's pain is a little different and you should just consult a doctor. My physical therapist told me to avoid using my compression brace unless really needed as it will help my recovery be more complete.