Osteoarthritis does not travel in bones; osteoarthritis is a health problem that affects the boney portion of joints, or those places where two bones come together to assist movement of the skeleton. It is not a problem of bone tissue as much as it is a problem of the cartilage that covers the bones within a joint. Osteoarthritis primarily takes place in those joints bear weight and are involved in the upright posture, such as all levels of the spine, hips, knees and feet.
There are two basic reasons that the cartilage of a joint wears down or becomes thinner to begin the degenerative changes that will eventually become osteoarthritis:
- Excessive physical stress to a joint from overuse or abuse - lifting weight that is too heavy for the individual; accidents and falls; being overweight; poor posture; working or walking on uneven surfaces
- Genetic abnormality that causes the cartilage to be weak and defective
Once the cartilage of a joint begins to offer less protection to the bone that is below the cartilage, the bone will be stimulated to protect itself from further harm. The body will deposit additional calcium in the areas of bone, as well as begin formation of bone spurs (osteophytes) that help to reinforce the abused bone tissue, as well as limit movement of the joint.
None of this process involves a process or a chemical that passes through bone; it is essentially a process that takes place locally at the site of the joint abuse.