I would see innovation in medicine as very problem based or driven. In the sense of Health and a patient and an illness become a problem to solve. So you can say that, once you have solved the problem, you have innovated.
Innovation would then be anything that improves diagnosis and treatment. This includes reducing side effects, improving healing times, and recovery rates.
Radical innovation in medicine should be circumventing some of the basic premises of healing, like artificial body parts etc. To rewrite the book of health.
See my paper on the types of benefits entrepreneurs build into new products, and see how the types are applicable to surgery.