I've got a knee injury from 3 years ago... Snowboarding accident. What's the best course of action?

In addition to investigating the trauma there are homeopathic remedies quite helpful for such injuries. Many are available OTC, but it is best to have a certified homeopath review your specific symptoms and recommend potency and dosing. I also highly recommend having certain homeopathic remedies on hand such as Arnica for injury and trauma. Another thing to keep in mind is that there are wonderful homeopathic remedies for concussion that can be used in conjunction with emergency medical care to speed recovery.

There is a lot you can do, now as a symbolic the knee represents a certain fear of moving forward and taking your step toward embodying your purpose.
Esogetic Colorpuncture has several ways of treating chronic pain, on the level of the brain with pain memeory that is established, on the symptom level and then we can investigate and see what is the background, where does the fear stem from. What kind of experiences have you been through that established a cellular memory of trauma or fear.
Hope this is helpful.
Cornelia