I need bilateral total knee replacements. should i have them done at the same time?

Can you walk?: If you are not in a wheelchair, then you should probably have one at a time. Less risks, and easier recovery. Indications for bilateral tka include inability to walk on each leg, severe bilateral flexion contractures, and health issues that make two anesthesias unlikely to be survivable. It is not something that should be done just for convenience, because studies do confirm higher risks.

Possibly: There is a slight increase in risk level to do them together. If you are overweight the risk goes up. If the surgery is complicated the risk level goes up. Of course twice as much pain.