I injured my lower back when 40. Now at 65 is considerably worse. The discs for all practical purposes are gone. What can he done at this late stage?

Depends. Non operatively you may need therapy and bracing, such as an abdominal binder, operatively you may need multiple level fusion. It depends on your health and activity level otherwise.
Therapy/Pain Control. The discs in everyone's back are degenerating or wearing out over time. This can be associated with pain episodically throughout our lives starting at age 16 or 17. Standard options include avoiding bending, twisting or lifting more than 20 lbs. The next level is physical therapy for back strengthening. Stopping smoking can help also. Trying lumbar injections 1-2 times a year can help.