Knee Surgery 101: Is This a Farewell or A Welcome Aboard?

THE OLD KNEES, DANCING IN THE NIGHT  (IF NOT THE NIGHT AWAY), WITH MY THEN 7 or 8 YEAR OLD SON SPENCER (WHO WILL LAUGH, I HOPE, AT MY POSTING THIS PIC)

This perplexes me: not unlike a bon voyage or the welcoming of a new baby, I wonder how to treat the knees as they approach replacement. Should I host a party to say good-bye, or a shower to welcome the new arrival, or arrivals? (At this point not sure if a solo birth or twins, though even if not immediate twins there will eventually be a sibling). They have served me well. What's coming has a tough act to follow. 

In my gut there is a sense that attention should be paid -- either way or both ways. Coming, going. The knee that's going away has been with me through quite a lot of adventure, turmoil and calm, who knows how many cartwheels, leg crossing this way and that way, polite ankle crossing, slapped in the joy of laughter, swimming countless laps, running a hundred miles, jumping jacks and squats, climbing hills and mountains, up boat ladders and grandly descending elegant  stairs, slumber and passion, frenzy and repose, kept me upright in countless pairs of stilettos, danced the night away so many nights, got banged and bumped, and the "boo boo" kissed sweetly by a parent as a child, and been complimented as an adult by husband just for how it/they looked. Now not politically correct, if it ever was, I recall a silver haired, pin-striped Time-Life VP who, after I passed him in a hallway on the 46th floor, said over his shoulder, "great gams." I was 21 and at the time had no idea what he was talking about.  Gams? "Mad Men" wised me up. 

Bumped, banged, bruised, buoyant, loved, adored, patted, WHATEVER.... they are my knees. I'm emotional. Sentimental. They were made in my mother's womb. They are part of my skeleton. They've been with me THAT LONG. They will be cut away from me and replaced with something manmade, possibly coming out of the assembly line as I write this, and def not womb made. How do I feel about that? How do I wrap my head around that? And how do I go on without the old and welcome and find comfort with the new?  

Leaning toward the welcoming party, but what are the appropriate gifts for new knees? Red lizard stilettos? I don't think so.