L4-5 loss of disc signal central disc protrusion ind. thecal sac. mild facet disease & central stenosis. l5-s1 loss of disc signal & shallow disc protrusion ind. thecal sac. mild central stenosis. is surgery only option?

Try Non-operative : First treatment option would always be physical therapy/rehab to strengthen core muscles groups. If that fails then epidural and or/facet injections using either steroid or plasma rich platelets. If that all fails then surgery would be last resort.

Back surgery: Most neurologists would say not to do back surgery unless there is progressive and unrelenting pain, and/or increasing weakness, muscle atrophy, and ongoing urinary or bowel symptoms. NB: nowadays, we have amazing non-surgical physical therapies and rehab. Furthermore, many radiology studies show ruptured discs can dry out and shrink over 7-10 months.