Few years ago we had a grey tabby who was an indoor/outdoor cat who came and went his own way.
On Saturday afternoon I was mowing the lawn and saw him lying in the grass near the back fence. He did not move as the mower came close, I checked him out, he could not stand and seemed to be in pain whenever I touched him.
I managed to slide a piece of thin plywood under him and lift him into the back of the station wagon, went to emergency vet.
Vet determined he had broken pelvis but the broken bones were in normal position he had been kicked or hit by a car.
Doc said take him home, lay him down gently with water and food where he could reach it then he said: Ive found if you can get all the parts of a cat together, they will be alright.
Sure enough, he lay there, napping. I gave him water through a bottle with nipple, fed him soft food on a spoon for week, then he was able to raise up enough to drink and eat from a dish. After a month he stood briefly, six weeks was walking short distances.
Lived another ten years, then one day he pawed on the door, let him in, he stretched out on the living room floor, flicked his tail a few times, lay his head down, took a deep breath, and died. We wrapped him in his favorite piece of old blanket, buried him beside some rose bushes. Cried for a week.