Hi Ryan,
1. CORRECT DIAGNOSIS
I'm sure you've seen the best specialists that can confirm if you really have AVN (Avascular Necrosis). On my first MRI scan the imaging consultant suggested AVN but the hip surgeons later told me it was 'just' arthritis.
2. BEST TREATMENT FOR YOU
Once that's confirmed, over time you would have discussed with your doctor the possible options: Medication (NSAIDs, osteoporosis drugs...), Therapy (Rest, Exercises -it seems contradictory but it's not-), and finally Surgical procedures (Core decompression, bone transplant, osteotomy, joint replacement).
Depending on each case -we are all different- some (or most) of the treatments are not an option for you, others might have been tried and didn't work.
For example, not sure if Core decompression, Osteotomy etc would apply to your case at all.
Again, Dr. Gross and other specialists you've seen would have discussed that with you. He surely is well qualified, one of the best, this is reassuring. Note that, from what I read, he also does THRs and Revisions, that's important.
So, it seems Hip Replacement is your best option in their opinion. Then you had to choose between THR and HR. And you leaned towards HR.
In the end, it's always the patient's choice. It's hard to take a decision when you dive into the unknown.
3. THE FEAR
There is never 100% guarantee it will work perfectly. But this is a given, the best way to minimize the risks is to be thorough while you walk through steps 1. and 2.
You haven't mentioned it but I guess one of your overriding thoughts is to wait, as some better alternative could come up in the not distant future.
That was my hope too. Later I came to the realization that any alternatives to hip replacement are not there yet, and even if there are they won't become mainstream for a good few years, because hip replacement (THR or HR) has a proven record with good outcome worldwide, and they last longer than before (even if placed earlier in life, when we are more active). And there are revisions now available (which were difficult not long ago), so there is a prospect of decent lifestyle for many years for patients that need surgery younger than usual.
But the real reason why many of us dreaded surgery is hidden behind that thought of "something new will come up", and it is a more powerful one: once you commit to do it, there is no way back. You get a piece of metal and the old (or young) hip is gone for good.
Life is full of irreversible processes, that's the 2nd law of Thermodynamics anyway, and hip replacement is just one of them!
4. HOPE
This is not a jail sentence, it's a solution to a very serious problem, you should be grateful there is a solution!
Once you've gone through steps 1, 2, 3 and the surgery is scheduled, you need to think positive and embrace it.
The homework is done, it's time to get ready (mentally, physically and logistically) and trust the professionals.
Think back 28 years and HR didn't exist (properly), THR was there but the materials weren't as good as now and expected lifespan for those joints was 10-15 years, Revision was in its infancy.
Doctors wouldn't be sure if you had AVN or something else until they cut you open, as MRI scans weren't there, and keyhole surgery was just about starting.
They would be afraid to operate on a young patient like you, you would have to wait until you couldn't bear the pain and miseries anymore.
Nowadays, still most of the population wouldn't have a chance for HR and many tests and procedures.
You are lucky. We are.
5. OUTCOME
Nobody can guarantee.
For me I had a few, incremental goals. Some of them I'll have to wait and see, as I'm only 14 weeks post-surgery.
1. Get through surgery and post-surgery without major complications. DONE.
2. Joint pain disappears. DONE.
3. I can walk without limping, and stand for as long as I want. DONE.
4. No more pain sitting, or with certain movements. DONE.
5. Get back to regular, pain-free, exercise. IN PROGRESS.
6. Get back on my bike. I WILL.
7. Jog. I WILL TRY IN TIME.
8. Run. I HOPE.
9. Run faster. WHY NOT.
10. Triathlon. I WILL (if I can't run, just walk).
11. Ironman. I DREAM.
12. The implant lasts longer than me. WE'LL SEE.
...