Motocross accident as a teenager tore up his knee. The meniscus cartilage was removed. 3 orthopedic surgeons told him to slow down because he was too young for a knee replacement. In 1997 came to Stone Clinic for Articular paste graft - after 2 months he was pain free for the first time in years. Later had a meniscus replacement. 5 years of heavy sports, snowboarding, riding bike. Another accident, fixed again with an articular cartilage paste graft. Later again, another accident, tore his meniscus, (chasing nephew)Fixed again. Now 10 years later and all is going well.