Between our bones are cushions of cartilage, which prevent grinding of the bones. When the layers of cartilage wear out, the bones begin to grind against each other, causing extreme pain. Under normal circumstances, the body replaces cartilage under control of tiny electrical signals. These electrical signals are created inside our body.
Because of diseases such as osteoarthritis, osteoporosis, aging or injury, the normal replacement of cartilage is disturbed, causing pain and inflammation.