Discs and cartilage serve to absorb shock and keep the bones from rubbing against one another. If the ligaments become torn or over-stretched the joint becomes unstable and resultant friction causes the discs or cartilage to become worn down causing a loss of height. The disc and cartilage may also become worn down by repeated motion. This loss of height causes further ligament laxity and thus more instability. The friction of the joint is a stress.
Bones respond to stress by making more bone.
Degenerative disease is merely the body's attempt to stabilize joints as the tendons and ligaments have not been able to heal because of lack of blood supply. If a patient has considerable degenerative arthritis the loss of disc or cartilage height causes a laxity of the supporting ligaments. This causes joint instability. This is the area where the tendon or ligament attaches to the bone. The substance used is sodium morrhuate which comes from cod liver fish oil and a local anesthetic.