Oh Pono...I want to tell you "Dont worry, be happy"...but it won't help calm fears no matter what any of us say.
Play this as you read the rest of my post here....
will put a smile on your face! I promise!

http://www.youtube.com/watch?v=yjnvSQuv-H4

Anytime "The powers that be" loom over us, no one can help but worry.
But worrying about this will NEVER change the outcome,
it won't change anything but your feeling icky over this till its done.

Your job will be is to gather your records and make sure all is current and correct. See what THEY will be reading about what your doctors think.

Take time to carefully read thru all of your records and if needing clarifications or changes make sure this gets done well before your reveiw.

You can call and ask them what these reviews entail.
Can do this annonomassly or give them your info.
They won't bite,... much!
This might help calm your fears a bit.

I've no doubt after reveiwing your records they will see that your case is same or worse than when first approved.
Perhaps this reveiw they will commute yours over to permanant status, then won't have to worry again.
Keep in mind, you're now much older, have had more surgeries and still unable to work and now under pain management.
I'd find it hard to beleive they'd take away what they'd approved years before, especially now under pain management with declining health issues.

Think you'd have to have gotten much improved AND your medical records state this as well....
Don't think they'd have you under pain management if you weren't very ill!
Takes an act of God to get into pain management for most people.

Never mistake feeling "better" while under pain management which can give you a little better quality of "life"...is why they give you pain meds, so you WILL have improvment, even if only just a bit,
make it where you can at least function on somewhat human level!
Worrying won't change any thing, will only bring you upset and greif!

You've got many others here in these forums who'll pray for you as well!
So not to worry!...Give your worries to me! LoL!
I worry about everything! and I too get fear struck anytime the mail contains a letter from Social security.
I've even worked part time too!
They've encouraged me to and has been zero problems, as long as I stay under a certain amount, make less than $650 month, all is well!
They don't take away a cent out of my SSDI checks unless I make much more for nearly a year.
They now have "Ticket to Work" program where you can work and continue recieving full payments with ZERO hassel by them.
They know if they were to cause problem with anyone trying to work,
word would get around then NO one would try to work.
The pay sucks, $10 per hour, but is something to do from your bed!
You can log onto their web site, read all you need about your upcoming reveiw.
I've had numerous reveiws and every 7 years I think is full reveiw and lots of paperwork to fill out.
But I doubt they even look into my case as my medical record is over 4 inches thick! I've had so much go wrong with me after being awarded SSDI.
I think, once they award you, is hard to "Kick" you off it.
You'd have to be dancing and running marathons before they'd pull the rug out from under you!
Don't worry, be happy man!
Now...really, don't ya worry!
Be happy!