Has alien abduction been fully ruled out? Happened to me once and I have no recollection of 2009

Sorry about your accident! Of course the recovery is painful, but luckily you didn't need surgery.
Could be there was a dog involved? A friend of mine had a nasty fall when a dog crossed in front of him, the dog ran away apparently unharmed.
I had a memory loss similar to yours years ago - I was just riding along the white line, heard a screech, next thing I knew I was on my back looking at trees and sky, didn't know where I was or how I got there. Someone said "Don't move, you were hit by a car, the ambulance is coming". Turns out a zigzagging drunk driver hit me from behind, I flew into the air, was uncounscious for about 5 mins, people thought I was dead at first. Consequencies were comparatively minor, broken scapula, bruises and road rash all over. I never remembered that crash, and I think it's better that way.