What constitutes a “special or unusual risk” for medical malpractice?

He explained that “special or unusual risks … go beyond those that are probable in respect of the surgery or therapy involved in a particular case and could relate to serious consequences in the particular instance even if the risk be a mere possibility.” He explained further in Reibl at p. 884: The Court in Hopp v. Lepp, …, also pointed out that even if a certain risk is a mere possibility which ordinarily need not be disclosed, yet if its occurrence carries serious consequences, as for example, paralysis or even death, it should be regarded as a material risk requiring disclosure.