There are a several waterproof dressing options that work great and allow you to shower, but clear this with your OS first. Unfortunately the supplies are expensive. My first knee had a two-week dressing called Aquacel ag (I think) that was applied in OR and stayed on until my first post op appointment. Then there's Tegaderm and/or Opsite waterproof barrier films. Both films function similarly, so it doesn't matter which you use. They should be available at larger pharmacies that stock wound care supplies, or from Amazon. Get the largest size. Also buy some Telfa 8" x 3" non-adherent sterile pads, or plan to shingle a few smaller ones. Lastly, buy a box of ChloraPrep Sponge Applicators, or sterile antiseptic swabs.
If you will have a Home Health RN, (s)he should have the above supplies, or something similar, to change your dressing for you, but I'm told they often arrive poorly equipped. I declined the Home RN and changed my own incision dressing every two or three days. My RN friend taught me what to do: 1) Wash hands thoroughly & air dry. 2) Squeeze the plastic wings on a ChloraPrep applicator to rupture the antiseptic vial, then squeeze the handle to moisten the sponge. 3) Gently dab/wipe the incision with the antiseptic-soaked sponge. 4) Air dry. 5) Apply sterile gauze to cover the incision. 6) Apply Tegaderm or Opsite barrier film. 7) Enjoy your shower!
Here is a video:
(it bugs me that she didn't wash her hands!)