Welcome to health care magic. 
1.There is a disc between the 
vertebral bodies helps as a shock absorber effect, the disc contains maximum percentage of water, due to degenerative changes when the water content / hydration is lost the disc slips / bulges.
2.There is 
disc protrusion at different levels T12-L1, L4-L5, the disc at this level seen compressing the 
nerve root.
3. 
Retrolisthesis - is posteriorly moved vertebrae in retain to the vertebrae below it. 
4.Facetal arthro-pathy at different levels - inflammatory condition of the joint at mentioned levels.
5.All these findings are seen as age related changes / excessive joint usage / heavy working nature.
6.Treatment in this case will be initially exercise followed by 
physiotherapy - finally operative / interventional is treatment of choice.
Good luck.
Hope i have answered your query,
any thing to ask ? do not hesitate to ask.
http://doctor.healthcaremagic.com/doctors/dr-ganesh/62888