In reading in MRI report what does the below sentence really mean? Degenerative change in the thoracic spine. No obvious spondylolysis or listhesis.

Wear and tear. Degenerative change implies that the discs are drying out a bit, and there may be some bony changes, such as small spurs, but the report suggests normal alignment and lack of need for invasive procedures such as surgery. Indeed might be consistent with your age. Talk to radiologist more if you need a visual explanation.