There's also the stigma against defiling the dead to learn about anatomy, so surgical knowledge is probably limited
Actually it looks like that is being practiced in Tamriel.
In Cyrodiil, a few Necromancers who have served the Empire are given the corpses of criminals and traitors to use legally. This provides those who have acquired such a post with a fresh supply of corpses, most of them young, strong, and intact.
(...)
Summerset Isle is even worse in some ways. Some Altmer born into the most respected noble and scholarly families are actually allowed to study the dead in the open. Their research, however, seems to be centered on finding ways to extend their lives even further rather than the more practical uses of our Art. A Necromancer of any other race caught in Summerset Isle can expect the worst possible punishments.
- http://www.imperial-library.info/mwbooks/corpse_preparation.shtml
But there is probebly also a reason why that book didn't show up in Oblivion.