It seems to me that the scar tissue, which I have alot of in the glutes, is only as deep as the needle is long. Beyond that point, there should be no scar tissue... where the actual depot of oil is. I'm not sure about this, but it just makes sense to me. That's why I don't worry about oil being injected into scar tissue.
But let's say you've been using nothing but 1 1/2" needles for years, then you start using 1" needles in that same site. That would be something I would NOT do, because then you would be injecting INTO the scar tissue.
Someone correct me if I'm wrong, or inaccurate.
KB