Fantabulous news - my discs are fine. The MRI shows massive swelling in the facet joint between the 4th and 5th lumbar vertebrae and around the two roots of the nerves (forgot their names) that then join to make up the sciatic nerve. The fluid is trapped in the joint because of the swelling. The same thing is true to a much lesser extent on the other side.
The orthopedist said that an injection of cortisone into the joint will make the swelling go down with amazing quickness and within 48-72 hours I will be hopping about good as new and it will be like it never happened and my nerve will function again, undamaged! No more pain, also, no more leg-collapsing! And my career as a ballet dancer, figure skater, and marathon runner can continue!
Unlike if it were actually a torn disc in which case it would be a hideous months-long deal with multiple injections and continuing pain and disability with recovery in a time and galaxy far far away.
It was interesting to see the MRIs. He showed me the normal discs, and the normal joints in which there are some gray blobs that are cartilage and stuff, and then the joint where on the right side there are gray blobs and giant white-hot looking extra bad evil mean yucky blobs that are the fluid and swelling.
It is nice to have a doctor point to a scientific looking chart that has obvious empirical evidence not dependent on some one moving my legs into various positions and waiting for me to say OW and start crying. (As we also did. When I reach OW I tend to try to wrestle the doctor's hand away while with my other hand grabbing the table white-knuckle style and yelling OW and then I start crying and demand a pause in the body-part-moving around diagnostic thing.)
It is even nicer to know that this may very well be finite! Over! Soon! Not something I have to adapt to for more weeks or months! Fixable!
I wish they could do it right now and I didn't have to wait a week. Also I wish someone had referred me immediately to this doctor, think of the pain and horribleness I could have avoided!