The First Cut is the Deepest?

Scientist have opined, on the basis of animal studies with human growth hormone preparations, that contaminating proteins on surgical instruments may 'seed' the brain, in neurosurgical procedures, with factors implicated in Alzheimer's disease (https://www.theguardian.com/science/2018/dec/13/neurosurgery-could-spread-protein-linked-to-alzheimers-study-finds). Their advice is that surgeons should take more care when sterilising their instruments. I seem to remember, however, that earlier studies with prions (highly resistant proteins implicated in CJD), suggested that there was no such thing as a completely safely re-utilisable (after sterilisation) surgical instrument?