You can always find examples against. That doesn't necessarily tip the balance.
In my view it is a pretty big risk to load up on a key forward with past knee history, which we'd need to do to get someone like Walker. Yes, some recover, but a lot don't and I'd far rather chase someone without that added risk factor, who would cost basically the same wage.
I accept that it isn't as if we're advocating chasing Menzel, who has now had three, but still.