What is "djd" of thoracic spine?

Some kind of: Arthritis, the common type of arthritis effect the bod, usually wear and tear process, some get more than other have many factors involved in it.

Age related change: DJD is a poorly constructed phrase which improperly indicates that someone has a disease. This is not actually the case. Age related degeneration of the spine is part of the aging process. When these changes affect the mid-back (Thoracic spine), it can possibly (but uncommonly) cause disc, facet joint, and/or narrowing changes affecting the neural structures.