I have a bad knee, but not so bad that I'm dependent on a cane. I walk fine without it, but I walk further and have less pain that night if I use one.
My favorite is a Leki Wanderfreund. Because I'm not dependent on it, I forget to bring it on trips, so I've bought a couple at the camp store at my destination. I have 3 now. I left one on the trail once, and someone found it and mailed it to me, since I put a name and address sticker on most of my gear.
My first one had a shock absorber, but I find that doesn't make much difference, even though I put a lot of weight on it.