Welcome to HealthcareMagic forum.
From what I understand your grandfather was diagnosed to have multiple slip disc based on Magnetic Resonance Imaging
Yes, both conservative and surgical treatments are available to treat slip discs. Surgical treatment is restricted only to those cases where there are neurological deficits secondary to nerve root compression
and where conservative treatment have failed to relieve the symptoms.
That being said, spine surgeries are definitely associated with risks. There is a small possibility of worsening of the condition. Besides surgical and anesthesia
risk are plenty in elderly patients.
Weighing the benefits and risks, I feel there are plenty of risks involved in operating an 87 year old gentlemen. And the choice to manage him conservatively is right one.
Continue with braces. If the pain is severe a brief course of anti-inflammatory agents / steroid
injections can be used. Discuss with his treating surgeons.
Hope this helps.