There are more important things to do before surgery
than one's nails.
If you smoke, quit doing that. Take oral iron and multivitamins to ensure that you have a normal hemoglobin. It would help to improve your stamina through exercise so that you can get ambulatory sooner, following surgery. https://www.asahq.org/whensecondscount/preparing-for-surgery/prep/preparing-for-surgery-checklist/