After more than 30 yrs of wanting to learn a Martial Art, I have finally started at 41. I have chosen Shotokan Karate due to being good friends with a Shotokan teacher....that and it fits my budget. I have had one lesson. My friend/teacher is aware that I had knee surgery 6 yrs ago and said we can work around it. He is also in his high 50's so can sympathize w/ my age. I am healthy, still athletic, fast, flexible and agile. Working towards a simple self-reliant life, I'm still worried about my knee though. I can not afford to become prematurely crippled. And with 25% of my meniscus removed, my chances of developing arthritis in that knee have significantly increased...not taking undue stress into account...like Karate, perhaps.?..? Is there anyone out there in a similar situation of knee injury and or age that can offer their experiences in the Martial Arts? All advise/wisdom/experience welcomed and appreciated. Thanks!