Tough break, Mark. Let's see what the doctors say and what the next few weeks will bring. It may be that there is some diet, lifestyle, or other random factor involved that will tip the risk/benefit balance back in your favor-- or not.
How do we know when the moment has arrived? Well, I think it came for me this year, just not with this sport. I went down to the beach about three weeks ago to go body boarding. I watched the conditions for 10 minutes. Lifeguard on duty, check. Surf two feet or less, check. NO other surfers in the water-- that never used to stop me, I'd still get rides that would get the tourists of their blankets and taking pictures. (I'm only an intermediate, but my specialty was riding crap waves.) Close outs constantly, not good, but not a deal breaker. Close out close to shore, that's much more problematic, but I've managed that in years past, too.
Waves that are impossible to read-- literally. In the 10 minutes I watched, there were two rideable waves, but in all honestly? I could not have picked them. And there were about six waves I probably would have gone for, but that could have been neck-breakers.
The beach was badly eroded, too, so you WILL face-plant if you don't yank the nose of the board up as you get near the sand. Drop off steeper and closer to shore than I had ever seen it.
And I realized: I'm done. Walked back to the parking lot, stared out at the ocean, said a prayer to my higher power, and thanked my homebreak for almost a quarter century of epic rides and great fun. Body boarding made me a different person, changed my life in so many ways I can't even count. I've hit sharks-- seen a dorsal fin go right under my board-- been stung by stingrays, chased by seals, and escorted by dolphins. Got back in my car and cried, yelled, and pounded the steering wheel. I'm on blood thinners. The odds are just not in my favor. And I've been beating them for too many years-- decades really.
Might I go out again? Sure, in Santa Barbara or Kauai, if conditions were right. Could I get another run at my homebreak? Possible, but really unlikely.
But those years when I'd get in 15, 20, 26, or 30 days of riding a season are long behind me. It's not the same if you don't do it all the time, it's always like your first day out. I WILL go again-- somewhere, occasionally. And you may be able to ride again, somewhere, too-- maybe with max assist, maybe only with a buddy, maybe only within ready ambulance range. It will be different, but if it breaks that way, take what you can safely get and no more.
You may get a reprieve, you may not. The uncertainty is terrible, and for me, the decision is never completely final. But for me, a certain peace came with knowing that yeah-- this is probably it. I gave it everything I had, and I didn't get killed or disabled. There's a beauty in that, if it turns out that day has come for you.
Sorry to ramble.