I'm confused, what exactly was the surgeon doing during the arthroscopy, was he asleep? Shouldn't he have seen the arthritis while actually in the hip with a camera? The MRA didn't show anything wrong with my hip, but they found arthritis during the HA. I have photos of the inside of my hip and it's very clear, after it was pointed out even I with an untrained eye can see the arthritis damage. Did you ever get any more information about the operation? Can you ask to see the notes?
Well, anyway, what you are describing, the sharp pains, that's what I had before the op and for a while after, although gradually over the last few months it's lessened considerably (I had microfractures to try and help with it). I do still get it, but only a few times a week now, and mostly because I've moved awkwardly, twisting through the hip most times. I also had frequent really bad lower back pains and SI joint area pains and soreness, either caused by the limping, or partly defered from the hip joint itself. I think in my case the microfracrures are doing their job now, so although it's not any comfort to you, I'm feeling in really good shape at the moment.
I feel so sorry that your HA didn't work out well. To be honest, I'd be inclined to start asking questions about who did the surgery, what was their experience in this procedure, and why weren't you told about the arthritis afterwards (they really must have seen it). There can be a fairly high conversion to THR within 2 years after arthroscopy if arthritis is found (my surgeon told me that), so I'd keep asking for help with the pain and if it's still too much after the injections, bang on doors and ask to be refered back to the surgeons.
I really do hope things do turn around for you.
How's your husband?