OA is a disease of the joints. It predominantly affects the cartilage that lines the bones of the joint. Cartilage is the dense rubbery tissue that covers the ends of bones in a joint. In healthy people, its surface is smooth and slippery, which allows the bones in a joint to glide over one another easily. Cartilage also absorbs energy, like a shock absorber, from the jolts associated with movements such as walking. In OA, the cartilage of joints affected becomes inflamed and roughened and wears down. As the disease worsens, the cartilage can disappear completely, so that eventually one bone may rub against the next.
OA affects more than just the cartilage between the bones, however: It also affects the muscles, bones, ligaments and lining of the joint. The bones of the affected joint can undergo many changes. For example, small growths of bone, called osteophytes (“bone spurs”), can develop around the joints. These bone growths can lead to a knobby appearance and limit the motion of the joint. Small pieces of bone or cartilage may also break off and float inside the joint space, causing pain and further damaging the surface of the cartilage. If a patient has OA of the spine, the bone spurs can press on nerves and cause numbness, tingling, or weakness in the arms or legs.
Osteophyte
An outgrowth of bone.
The bone that underlies the joint is called subchondral bone. In joints affected by OA, subchondral bone can become hardened and brittle and form cysts. In addition, the bone can lose its normal shape, in a process called bone remodeling. Scientists believe that subchondral bone remodeling plays an important role in the worsening of symptoms and is a common reason for joint replacements. Some new therapies for OA are aimed at inhibiting bone remodeling. For example, investigators are studying how drugs that are currently employed for the treatment of thinning bones (osteoporosis) will affect patients with OA. These drugs could potentially be used as disease-modifying agents in the treatment of OA.
Bone remodeling
A cyclical process by which bone maintains a dynamic steady state through resorption and formation of a small amount of bone at the same site. Bone remodeling can occur as a result of joint disease.
When a joint affected by OA becomes painful, a person may become reluctant to exercise. As a result, the muscles surrounding the joint can become weak and thin from underuse. Without muscular support, the joint becomes less stable. This instability can lead to misalignment and increased wear on the joint, with resultant pain and disability. This cycle of pain, weakness, and worsening disease can be broken by use of pain medication and adherence to a regular exercise plan. If a painful joint keeps you from the activities you enjoy or from the exercise you need, speak to your doctor. He or she can offer a treatment that may help.
When a joint affected by OA becomes painful, a person may become reluctant to exercise. The resulting cycle of pain, weakness, and worsening disease can be broken, however, by use of pain medication and adherence to a regular exercise plan.
My finger, knee, and thumb joints get very stiff and even more uncomfortable in cool damp weather. Simple things like steering a car, opening bottles, and holding things become bothersome. I find that by using treatments like Tylenol, not carrying things that are heavy (over 5 pounds), and putting my luggage on wheels when traveling helps quite a bit. Also hand massages and warm towels on my hands and fingers help alleviate the discomfort.