I know someone who had surgery for their back. I think it was a laminectomy, but I think they fused his disks together. Not sure. Can’t recall all the details now.
Before surgery he couldn’t walk or use his bladder because of pressure on certain nerves. After surgery he could eventually walk and could urinate again, but he was in terrible pain for the rest of his life. Had to quit work while only middle aged. He went down hill over the next 10-years, and died.