I have grade 2 spondy at L5/S1. I've had this condition for most of my adult life (I'm 43)...but the pain didn't start to get really bad until roughly a year ago. At that point, I had an MRI...which confirmed what I already knew, but also indicated some other issues such as DDD, and severe bilateral foraminal stenosis. All of which was causing some severe right leg pain (sciatica). I was referred to a neurosurgeon, who basically laid out my options - physical therapy, epidural injections, or surgery. I opted for PT...did a 6-week course of it...unfortunately, it didn't help. I'm guessing the PT didn't work, because I am already very active (I'm a triathlete) and exercise daily and was doing most (if not all) of the prescribed exercises already in my daily routine. I was not willing to go the surgery route, and I wasn't convinced enough of the success rate of injections, so that option was out too. I also didn't want to rely on pain killers for the rest of my life, although I did get a prescription for Tramadol and used it for about 6 months, before I decided to kick that habit. I basically took matters into my own hanRAB back in January 2008, and bought myself an inversion table to use at home. I had done some reading up on them and it seemed like a worthwhile option to try at the time. I started using it daily for about 4-5 minutes, first thing out of bed (after my in-bed stretches). I guess I'm one of the lucky ones, because it worked for me. My leg pain is completely gone. I'd say it took somewhere between 2-3 solid months of using the table daily, before I started to feel the pain diminish. I still use the table every single morning and usually again after a long bike ride (I'm an avid cyclist and often do 100-mile rides).
Inversion tables aren't for everyone and I'm sure there are plenty of people who will argue that they don't work or are even dangerous. But it worked for me and I've been happy with the results. Do I still have lower back pain? Sure I do, and that probably won't ever go away entirely due to the nature of this condition. But it's at a tolerable level that I can deal with, which is all that matters to me. That and the fact that my leg pain is gone...makes me one happy camper.
I'm proof that you can live and enjoy life with Spondylolisthesis and not have surgery in order to do it. Exhaust all of the conservative options first, before making a decision on surgery. Surgery should always be the last resort.