Okay, but for various sharps, blades and other cutting tools, keep in mind that repeatedly heating and cooling innately dulls them. Taking metal through temperature ranges that result in expansion and contraction mess with the honed edge. Think about metal as if it were a malleable wax candle.
Not to mention that mere pressure against skin on a cutting edge effectively bends and dents the edge until it becomes dull. That's what happens to IV needles, just the pressure to pierce skin alone ruins the point. How many times do you get to re-use a safety razor after shaving your beard or legs/armpits? Was the activity really very stressful on the blade?
And yet, maybe you'll get 5 passes (with a multi-blade razor on a thick beard) before it's pulling at the hair and skin, and you notice it's painful to shave with.
So too with surgical tools. After so many cycles of cutting, then heating and cleaning, you're pressing a dull butter knife against skin and whatever else you're cutting, relying more on cutting by sheer pressure than using the sharp edge to separate the tissue.
And then you can't stop the bleeding because the cut was wrong, the patient dies, you get sued (you DO get sued), and maybe you lose your license, reputation, time and money. So balance it against, just buying a $900 object brand-new.
But, yeah, how about sharpening them again? But with what? An angle grinder plugged into an extension cord? A stone wheel down in the metal shop? Not quite... I really don't know all that much about cutlery, but getting a blade perfectly sterile after sharpening it is probably something that is best done by automated factory machines, at which point the blade may as well be new anyway.
Why are they $900 in the first place? Seems like about an order of magnitude more than any reasonable cost. It's not like it's that rare of an item, there are ~100k of these surgeries performed annually just in the US.