 Get started today at Masterdex.com. Masterdex.com. Kurt was a firefighter who retired because of a meniscus tear and osteoarthritis in his knee. Then he had stem cell therapy with Dr. Mark Wagner, MD. Kurt, did stem cell therapy help? It was a life changer for me. I mean, when I retired, I wanted to ski, fish, and play golf, and those are the three things I loved doing, and Mark took care of me. Now, if you retired because of the knee, you must be thinking about signing back up again.