I have been told by several docs I can't ever have more than 3 in one
location in a year because more will deteriorate cartilage. I can't have more in lumbar spine, shoulder, etc.
It may be that your pain is coming from a different spot. The nerve pinch may not be at the joint at all, just covered temporariy. If your pain is radiating down your leg, especially if both legs are involved, it's possible a type of spinal or caudal (tailbone) injection will help). Caudal hurts for a few days, but it quiets the huge batch of nerves that exit the bottom of the tail bone just like the hair on a horse's tail.
If your pain is more along the side of your spine you should ask about
a TENS unit. Pinched nerves cause horribly painful muscle spasms that run up one or both sides of the spine. Your pain doc can decide if that would help! Another option for muscle spasm is 1 mg of diazepam (Valium). That's a tiny dose - half the smallest pill, but it is the best muscle relaxant out there. It can make you sleepy until you get used to it. Don't plan to use it forever or increase the dose because it is addicting.