Several kinds of supporting and moving parts, including bones, cartilage, muscles, ligaments, and tendons, help the knees do their job (see box âJoint Basicsâ). Each of these structures is subject to disease and injury. When a knee problem affects your ability to do things, it can have a big impact on your life.Knee problems can interfere with many things, from participation in sports to simply getting up from a chair and walking.irtually all of them have the potential to affect the knees in some way; however, the following are the most common. 1  Osteoarthritis. 2  Some people with knee problems have a form of arthritis called osteoarthritis. 3  In this disease, the cartilage gradually wears away and changes occur in the adjacent bone.