90% of bunions are inherently genetic. 10% is due to footwear - tight, pointy shoes. High heels.
So after bunion surgery, we always quote patients a risk of recurrence of 5-10%. Of course surgical technique is important.
What patients can do to reduce the risk of recurrence would be to wear broader/ open-toe shoes, that are not too tight. Wearing lower heels would also be good advice.
Of course sometimes patients have to attend functions where they might have to wear high heels/ stilettos. This is alright, but I generally advice patients to try cut that down as well.