Will Previous Knee Surgery Affect Liposuction?

I would say if you have recovered uneventfully and if you were one of my patients, I would feel comfortable performing liposuction on the thighs.
Make sure you see a board certified plastic surgeon for your surgical procedure.
Good luck.

As long as the incisions have healed on your knees and you don't have swelling that could be bothered by the compression garment after liposuction you could probably undergo the thigh liposuction with no concerns of it being interefered by the knee surgery. Do check with your orthopedist, though, prior to booking the liposuction.

 If the knee surgery was endoscopic  it should not affect your liposuction and probably not even if it was opened. You can ask your surgeon when he evaluates you.