Most people would highlight a medical issue due to a grade loss.
Sure, you can write an essay about dedication and this is an example.
On the flipside, might it scare them away, like you may have an issue they won’t want to deal with?
In the end, does mentioning it add to your candidacy ? If so, write an essay.
But mention it - no. Why ? You did not struggle because of it.
Personally, I’d write about something else but if you can weave an essay to highlight yourself, to show your personality, drive etc or how you fit there, then sure.