Stay in India more than a year with green card

I need to go to India for a medical treatment & may stay more than a year. I have recently received green card with my spouse. I would like to know about re entering to usa if I stay outside usa more than a year. Will there be any challenges? Do I need to consider anything before my travel?

If you are staying outside of the US for more than one year but less than two years, you will need reentry permit.
If staying more than two years, you will need to apply for SB-1 immigrant visa to reenter.