To be honest I don't think anyone has a good explanation for all my symptoms. I've asked a few experts (as in leading scientists in the field) and they have different opinions. If you're interested in the details, read on.
What I do know is that when my surgeon opened my ear on suspicion of otosclerosis, he did confirm the diagnosis visually (it is actually visible to the naked eye - you just have to push the ear drum to the side to see it), and there were 4 doctors present during surgery so I think I can trust the report.
However, I really don't fit the mold: otosclerosis is normally a slow progressing disease. It takes years if not decades to degrade your hearing to the point that you start thinking about hearing aids or surgery. In my case, a few weeks is all it took to create a 50 dB air bone gap. My initial SNHL was sudden, overnight. In addition to this, nobody in my family has this (it is supposed to be hereditary), and also I'm a male (it is supposed to hit females twice as much).
The other part of the puzzle is that I originally showed symptoms of sensorineural losses, which then progressed to mixed losses (sensorineural + conductive). Mixed loss are typically indicative of problems with both the middle ear and the inner ear. I also suffered from bad hyperacusis at that point.
I did the surgery and H went away almost completely. My air bone gap closed and I'm now left with sensorineural losses in the high frequencies.
If my problem was only in the middle ear, I should not have sensorineural losses.
When I try to make sense of all the info from the various doctors and neurotologists, I think that what may have happened to me is that a pathological focus (i.e. a bone remodeling site) started damaging the area where the middle ear and the inner ear connect, which is around the stapes bone (it's the most common area where damage starts in otosclerosis). This, unfortunately, created damage on both sides of the "border", creating the mixed loss. The middle ear side was fixed with surgery: no more conductive losses and H. The inner ear side did not get fixed and may actually have been hurt a bit more during surgery: it is not uncommon to have high frequencies take a toll after a stapedotomy. The area where the prosthesis gets inserted is where the footplate of the stapes is which is at the base of the cochlea. That is where the high frequency hearing apparatus resides.
My guess is that the disease hasn't progressed into the inner ear far enough to be clearly visible in a CT scan, but it is doing enough damage at the periphery of the cochlea to impact the high frequencies.
So to go back to your question, I think there was (and still is) a component of my issue that is related to the inner ear, even though the most common cases of otosclerosis are pure middle-ear issues.
What do you mean by "a 50 db air bone gap"?