That's a strategy but there are issues with immune rejection since that's a xenograft. I think there are some products based off of this concept for other areas (skin grafts) after removing all xeno-cells from the tissue, but articular cartilage is more difficult to remove/replace xeno-cells with autologous or allogenic cells.

I think cadavers are the typical source. Since there's no blood vessels in it, tissue rejection isn't as much of a concern.