1 year out, bad knees.

I am One year out and have lost 140 lbs but my knees have gone out on me and I am now facing knee replacement. I am 61 years old and need to know what type of exercises I can do now that will not hurt my knees at this point in the game before I have to have them replaced?? I bought a cardio glider after my gastric bypass but am afraid to use it now as it used to hurt my knees before they gave out on me, now I'm afraid to use it as I do not want to hurt them further. Any suggestions would be a help. Thanks.

 Water aerobics is a great workout and low impact on your knees.
Shallow Water aerobics is low impact and Deep water aerobics is zero impact.

how are your knees with a stationary or spin bike?  i find that when i have knee issues, it doesn't crop up as much on the bike.

I'm sure your doc or physical therapist has given you exercises you can do with weights or resistance bands.  Strengthening is always good.  I would assume some weight-bearing exercise like walking is still important.  I also agree with the bike and water suggestions.  Maintaining/building strength is one of the most valuable things you can do for yourself - especially with impending surgery.

Linn