Wow, 10 pounds!
If I give you my 10, will you lose it for me? Pretty please?
I'm pretty cautious. I wouldn't use an exercise program that created joint or back pain. My body only came with one set. Losing excess weight should make your joints more comfortable, not less.
I don't know if this helps, but bicycle seats need to be adjusted so the knee is
almost straight (one inch short? Ask a bike store.) when the pedal is at the bottom. Too low and you are straining your muscles. Too high and the leg never stretches out, and maybe muscles get too short. An elliptical is a lot like a bicycle.
Some ellipticals also have a forward/backwards seat adjustment. Playing with this might make you more comfortable.
Taking rsk8d's advice on getting more exercise variety:
Gentle jogging (or try racewalking) is easier on my knees than biking.
Some kids at a local rink are taught to run up and down stairs for about 15 minutes.
Swimming laps with many different strokes is great.
I recently tried another exercise. Wear a float belt in a pool (if you need the belt to float), then run in place without touching bottom.