A disease is defined as impairment of the normal state or functioning of the body as a whole or of any of its parts. Therefore the term diseased spine refers to an abnormal state or functioning of one or more parts of the spine resulting from various causes, such as abnormal physical stress placed upon tissue of the spine, infection, inflammation, genetic defects, and environmental stress.  The diseased spine is characterized by an identifiable group of signs and/or symptoms attributable to an abnormal process.   Some diseases are acute, producing severe symptoms that terminate after a short time whereas others such as arthritis may be more insidious in their development and become chronic.