Tingling/Numbness in Legs

In March 2015 because of Spondylolisthesis and DDD I had a fusion of the S-1 thru L-4. I was a runner, long distance cyclist, cross country skier...so I was in excellent physical condition and I became a walker and worked my way back. After 18 months PO I became a Certified SPIN Instructor. At about 2 years PO I had some leg numbness and tingling. I went back to my surgeon who took X-Rays and couldn't see anything and offered to refer me to a good Neurologist. I declined and the condition went away.

Being a man and not thinking much...I would forget I ever had surgery and engage in some lifting, bending, etc. Well back in about April I have been experiencing on and off numbness, burning, and tingling in both lower legs, ankles, and toes. It is happening pretty frequently. I went to my PMC physician (my surgeon's office said I am considered a new patient because I haven't seen him in a year and he isn't accepting new patients) and she ordered an MRI which I will get next week. The only plus is I do not have leg pain like I did before my surgery. Has anyone else had similar issues, and if so, what was the outcome? I never had the spinal injections and they scare me to death. I know that they were not approved by the FDA but many insurance companies require them before attempting surgery. Fortunately they wouldn't have helped me before surgery.