I’ve worked with a lot of people who has had multiple back surgeries. I’ve been through it myself. So I know what you are going through. It’s rough! You need to wait 6 months before going back to the gym to ensure the bone fuses together. You must change the way you workout. I’ve learned what to do and what not to do in general. Back trouble is a very individualistic thing and training adjustments must be made that work for you. If I can be of assistance please ask. You don’t want a 5th surgery. Wishing you the best!