A physician surgeon friend enlightened me about the story I posted last week. I was not 100% accurate in what I wrote. I always appreciate feedback about my blog posts, especially if it highlights an error on my part. The following is what he said.

John,
I’ve been meaning to respond to the e-mail from you that I saw Saturday. It’s the one on the artificial meniscus. I do not know much about it but I think your message was not entirely correct. Menisci are cartilage but they are fibrocartilage and when a young person (usually athlete) “tears their cartilage” it is the meniscus and this usually leads to a partial removal or repair. In the ‘old days’ we use to just remove them. Damaging a meniscus does increase ones chances of subsequently developing degenerative arthritis but degenerative arthritis is the results of damage to the articular cartilage and when related to a torn meniscus develops years later. Most cases of degenerative arthritis are due to the ‘wearing out’ of the articular cartilage for reasons not fully understood and not actually related to meniscal damage. Add to this that fibrocartilage ages (like all collagens in our body) and most of us over the age of 50 have some degree of meniscal damage. That contribution to subsequent degenerative arthritis is not understood.
Having an artificial meniscus to replace a damaged meniscus is likely to be a wonderful thing but I suspect it will be used almost exclusively for the young athlete and not have a major or even significant impact on older adults incidence of degenerative arthritis.