Grade 2 anterolisthesis l5 on s1 with severe loss of disk height. moderate loss of disk height at l3-4 and l4-5. pars defect at l5. right leg goes numb after standing still for 5 min or more. surgery?

Probably: You need to be evaluated by a neurosurgeon if you have not. The neurologic symptoms you describe are worthy of aggressive treatment.

Really can't : Tell a spine surgeon needs to take your history, examine you and personally look at the films. At least there is no mention of spinal stenosis . That would be bad. Does not sound too bad just hearing it.

Spinal pain: It certainly time to consider advanced treatments, diagnosis, and possibly surgery. You have a bad spine with multiple pathologies. It's important to figure out if you have active ongoing nerve damage. An EMG will give you the information that you need. If you don't have active nerve damage try everything else (injections, decompression, chiro, pt) before surgery as many can avoid surgery.

Spondy: Usually try pt and injections first. Surgery if conservative treatment fails or there is significant neurological deficits.

Depends: The decision for surgery is not based solely on imaging findings - rather, surgery is usually reserved for cases in which the pain/symptoms are debilitating, and nonoperative treatment has failed. If those criteria apply to you, then surgery would be an option, particularly if there is anatomic pathology which corresponds to your neurologic symptoms.