I think the confusion lies within what those terms actually mean. You can have an annular tear (a tear in the fibres that coat the disc) without a herniation. Protrusions are when there is a bulge but no herniation. Dessicated means a loss of (for want of a better word) plumpness in the discs, again not a herniation. A herniation is where the annular tear becomes great enough to let fluid out of the disc (imagine squeezing a jelly doughnut). I have had 3 full herniations of L5/S1 (the 1st of which was operated on) and even I'm struggling to get a surgical option as it's just not deemed bad enough. To be honest if I had the choice again I wouldn't have been so quick to have surgery as all back surgery has consequences.

Hope this helps.