I had surgery for my partially torn ACL. I went in to have a meniscus tear repaired, but it turned out not to be the meniscus but rather the ACL. The Dr removed the portion of the ACL that had detached from the femur and that was that.
He removed roughly 1/3 of the ACL as it was getting in the way of the joint functioning normally. Basically, it was getting hung up in the joint.
I am about 95% percent right now and still trying to get the rest of my strength back. I went waterskiing this weekend and although I did not push it very hard at all, I still thought it felt pretty good. I am looking forward to playing another season of flag football starting in July.
I am not planning on having it reconstructed unless it fails completely.
That said, 80% is substantial. Do you feel any laxity? Does your knee give out?