What does this mean? l-5 s-1 there is central disc protrusion which contacts the thecal sac and bilateral facet degenerative change thickening flavum

Let me explain: S1 nerve impingement (at the L5 – s1 level) from a herniated disc may cause loss of the ankle reflex and/or weakness in ankle push off (patients cannot do toe rises). Numbness and pain can radiate down to the sole or outside of the foot. In your case the problem will be on both sides.

Arthritis : This means that you have a degenerated disc (l5/s1 disc level) that is bulging in the center. Also states other arthritic changes such as the joint (facet) degeneration, and thickening of the ligamentum flavum (ligament over the nerve sac). All these changes can cause spinal stenosis depending on how severe the changes are. Hope this helps...

Early stenosis: Age appropriate degenerative chanhges at the lowest movable level of your spine these are minimal changes and may be asymptomatic in many people.

Disc & Facet Issues: Looks like by the verbage you gave, your MRI suggests that you have disc herniation at L5/S1. "Central" just means in the middle of the spinal canal,"bilateral facet degenerative change thickening flavum" suggests arthritis of the facet joint and the ligament that protects the spine is thickened due to that arthritis. Protrusion is just another name for a herniation.