Was It The Right Decision? Options

[Grieving in Mich...]

My beloved 8 month old puppy, Jasper, ran out into the road Saturday afternoon and was hit by a truck. We rushed him to MSU Emergency and for a while it looked like he was going to be OK. He had a broken pelvis, bleeding into his abdomen and a rapid heart rate. They also felt he might have some kind of brain trauma that would or would not heal - a big unknown. They stablized him enough to sedate him but the bleeding would not stop so they gave him some drugs to help the blood start clotting. The drug didn't help. At about 8:30 that night we got the call that they needed to do surgery to find out where the bleeding was coming from so they could stop it. But there was a new complication. The team of radiologists looked more closely at his x-rays and found a fracture in one of the growth plates in his lower spine. The doctor told us if they did the surgery, which had to be done with him on his back, he would be paralyzed. With all the trauma and suffering our poor baby already went through, we didn't want him suffering anymore and we made the decision to send him on to God. He was a husky/samoyed/shepard mix - he loved to run. What kind of quality of life would he have if he were paralyzed? I feel so sick just writing this. Did we do the right thing? I'm in agony from all the grief.