Thank you for reaching out to us.
Wound dressings are usually considered to be a
chatzitzah.
Additionally, there are sometimes limitations on getting incisions wet, and medical safety is itself a halachic concern.
Please check in with your surgeon about when it will be safe to remove any dressings currently on the incisions and/or get the leg wet.
Mention as well that, if it could make a medical difference, a single
dunk in the mikveh would suffice and you could arrange to be the first to immerse after the water is treated.
Please don't hesitate to follow up with us.