Anyone with severe pain down their leg, weakness, or numbness and whose MRI and x-rays show a pinched nerve is often a good candidate for surgery. The longer a damaged nerve is left untreated, the smaller the chance that it will get better. For example, one of my patients had bad leg pain and weakness in her ankle. There was a one-month delay before she could have surgery, due to some of her other medical issues, and during just that one month, the weakness turned into a full foot drop. She couldn't lift her ankle at all. That's how quickly nerve damage can progress. She's actually doing well now and the nerve seems to be coming back, but I've seen patients that weren't so lucky getting function back because they waited too long. You don't want to let nerves get too squished and damaged because they may not wake up.
Some patients are not good candidates for surgery. I treated one man who had back pain for five years. He had a couple of degenerated discs, no leg pain or pinched nerves, but he is tired of his back pain. His best option was a better living program: exercise, stretching, cardio, and core strength. Not everyone likes the idea of changing their lifestyle, though. Those patients may find a spine surgeon who will perform a fusion or a disc replacement, but the success rate on those patients is not as good as it is for pinched nerves. I've seen patients that had fusions from very aggressive spine surgeons and their back still hurts. Now they have a stiff back and they aren't happy. You can't fix it at that point. So I personally am not a fan of doing fusions for back pain except under very specific circumstances, like in Marlene's.