Do you remember exactly what they did? I just searched for "spinal decompression surgery" and it appears that there are different types (for example, corpectomy, discectomy, foraminotomy, laminectomy, laminoplasty, laminotomy, osteophyte removal, and spinal fusion).

I don't know if we're allowed to put links in a post, but here's where I found the description:
https://www.healthgrades.com/right-care/spine-surgery/spinal-decompression-surgery