blue717,

You might see a chiropractor. Even if you don't want to be adjusted, you'll get the best anatomy lesson.
Some injections are diagnostic. A botox injection in the piriformis could relax the muscle and alleviate the pain.
Anyway, you could probably get in to see a chiropractor tomorrow, they are less expensive than mds, if you take your MRI they'll be able to read it.
I hope you find relief before you turn 74.