T-11-12 Significant disc space height loss and moderate disc bulge.
There is significant disc degeneration here, causing a "flattening" of the disc, and bulging of the disc. This probably doesn't mean too much, however.
Moderate to severe bilateral facet joint hypertrophy.
Severe arthritis in the joints of the spine, both on the right and left. This could cause back pain.
Severe bilateral facet joint hypertrophy.
This is a repeat of what was just said.
Moderate to severe left neural foraminal narrowing.
This refers to narrowing of the area where the nerves exit the spine, so the left nerve here could be getting "pinched". This can cause symptoms of pain that shoot into the left hip, or thigh, or down the leg (depending on the level of the spine). If you are referring to T11-12 with this statement, then this can cause pain that radiates around into the lower abdominal area.