MRI. How To Read And Understand. There Is A Superior

MRI. How to read and understand.
There is a superior endplate compression ftracture of L1 the intense adjescent bone marrow edema, resulting in approx 50% loss of vertebral body height ad 3.5 mm posterior retropulsion which effaces the thecal sac and contacts the ventral surface of the cord.

My question is: what does posterior retropulsion which effaces the thecal sac and contacts the ventral surface of the cord mean.

Does it mean the spinal cord was compressed by the thecal sac? And what is a thecal sac? What does retropulsion which effaces mean?

It sounds like the spinal cord has been pressed on by part of the vertebrae. Can that mean damage to the spinal cord?

Thanks!