Well an osteophyte is more or less a bone spur, it's a small growth that according to your MRI is touching or leaning on one of your nerves causing pain. S1 meaning your sacral or tailbone vertebra. What can you do?
Well, I'm sure your doctor has made some suggestions, maybe see a neurologist, or a chiropractor, my choice personally would be a chiropractor, be sure to do your research as not all chiropractors are created equal! If you do see a chiropractor be sure to show him your MRI a chiropractor may be able to re-align your spine and create more space so that distribute isn't leaning on your nerve.
These are just suggestions you need to discuss with you doctor as nobody here has your medical records or any idea of what your back has been through. Good luck!