I got an MRI 8yearsago. Finding are. .. There is mild hypertrophy of l4-l5 and l5-s1 bilaterally. -impression: mild facet arthropathy same spots..

Mild arthritis. Abnormal MRI scans are more the norm, actually. As we age, just like wrinkles of the skin, the disks and joints of the back age and will show signs of arthritis. This does not mean pain. The vast majority of people with abnormal findings, in fact, are asymptomatic. In the absence of pain, really nothing further to do. These findings i would consider fairly normal for age.
Facet. Not sure there is a question but facet arthropathy is a type of arthritis and can produce pain in the low back.