The tip of your nose and the firm tissue in your ear are both made of cartilage. On joint surfaces the cartilage serves many functions, but primarily it provides a smooth gliding surface which allows for efficient joint motion. When one smooth cartilage surface glides against another, the amount of friction between the surfaces is five times less than the friction of ice on ice . Individuals who suffer from osteoarthritis , the most common type of arthritis, experience a loss of this cartilaginous surface . As the cartilage degenerates, the bone becomes exposed, and the unprotected joint surfaces rub against each other.
Patients typically experience symptoms as the joint becomes painful and stiff.
Treatment has focused on controlling pain, strengthening the muscles around the joint, and ultimately, joint replacement surgery. New research has focused on attempting to reverse the arthritic process to restore the normal joint. Unfortunately for those who have arthritis, cartilage does not regenerate well in the human body. Unlike a damaged bone, which if protected will heal with new bone, cartilage does not simply heal with time. Scientists are unsure exactly why cartilage does not tend to heal well, but there are several theories.