What does L5/1 mean with regards to prolapsed disk?!

It will be L5-S1 which means Lumbar region disk 5 and Sacrum disk 1. They are being specific to the disc that has ruptured. This particular disk is the one that is in-between lumbar 5 and sacral 1.

18 yrs ICU, ER, and Operating Room nursing.

I also think that's what it means, but the use of prolapsed is interesting. Usually they are bulged, herniated or slipped, so prolapsed is an interesting term here. The one thing about having disc problems is that you have to have pinched muscles in the back to mess them up, for I don't know of any other way to get that much pressure on them for an extended period of time to cause the problem to happen. For that reason I would suggest you freeing up your back muscles to get the pressure off the discs and see what kind of pain you have left to decide what to do from there. Here's how to free up your back muscles for that relief:
Back:
(do from a sitting position)
Place your left hand on your left leg next to your body. Place your right hand over your left shoulder, fingers over the back and the palm in the front and firmly pull down on them and hold. After 30 seconds slowly lower your body forward and to the outside of your left leg, keeping your left arm fairly straight as you do. When you reach your lap remain there for another 10 seconds, release the pressure but rest there for another 30 seconds. Then reverse your hand positions and do your right side.
For best results relax your body first by taking a deep breath and exhaling then remain this relaxed.

I have the same thing. So does my husband both shown on mris, straight posture is no go anymore Back pain for the rest of life, and you may feel it down your legs ( sciatica) UNLESS surgery can correct it for you. But listen to the dr. He knows best. I've just been hopeless since my accident and accompanying pain

Personal experience

see an hio method upper cervical specific chiropractor.