The most common form of arthritis, osteoarthritis (OA) is also known as "wear and tear" arthritis, because it is caused by the slow and steady degeneration and thinning of the smooth articulate cartilage that covers the ends of bones. Healthy cartilage provides joints with a normal, pain-free range of motion and function and allows them to glide smoothly in their sockets, but osteoarthritis breaks down the cartilage and narrows the space in which the joint moves. Symptoms of osteoarthritis range from pain and inflammation to swollen, distorted joints.
Osteoarthritis most often affects the joints in the knee, hip, spine and hand, because those joints are often overused and abused. Increasingly, people who work at computers every day are developing osteoarthritis because of the repetitious nature of keyboard entry for hours at a time. In addition, the joints in the knee, hip and spine have to carry your body weight. That's why people who are overweight or obese are at higher risk for developing osteoarthritis. Osteoarthritis predominantly affects people 45 years of age and older, but it can also occur in young people as a result of a knee injury or overuse in recreational or job-related activities.
The Centers for Disease Control and Prevention (CDC) reports that osteoarthritis affects 27 million American adults. A painful joint disease, osteoarthritis can interfere with your ability to work as well as limit your daily activities and quality of life. The CDC predicts that nearly one in two people may develop symptomatic knee osteoarthritis by age 85.
Osteoarthritis causes the cartilage in your joints to become stiff and lose its elasticity. The stiffness makes the cartilage more susceptible to damage. Over time, the cartilage may wear away in some areas, greatly decreasing its ability to act as a shock absorber. As the cartilage deteriorates, tendons and ligaments stretch, causing pain. If the condition worsens, the bones could rub against each other.
You may experience one or more of these common symptoms of osteoarthritis:
- Joint pain, aching and soreness, especially with movement
- Joint swelling
- Joint tenderness when you apply light pressure to it
- Pain after overuse or after long periods of inactivity
- Joint stiffness, especially after sleeping or inactivity
- Limited joint movement as the disease progresses
- Grinding of joints when moving as the cartilage wears away (in more advanced stages of osteoarthritis)
- Extra bits of bone known as bone spurs, which feel like hard lumps, may form around the affected joint
- Bony enlargements in the middle and end joints of the fingers which may or may not be painful
The symptoms of osteoarthritis may resemble other medical conditions or problems. Always consult your physician for an accurate diagnosis.
There are two classifications for osteoarthritis — primary and secondary. The cause of primary osteoarthritis is unknown. The cause of secondary osteoarthritis is another disease, infection, injury or deformity. Risk factors associated with osteoarthritis include:
- Heredity – Slight joint defects or double-jointedness (laxity) and genetic defects may contribute to the development of osteoarthritis.
- Obesity – Over time, excessive weight can place undue stress on joints such as the knees, hips and spine.
- Injury or overuse – A significant injury to a joint, such as the knee, can later result in osteoarthritis even if your injury was treated properly at the time. Repeated overuse or misuse of a joint may also cause injury.
- Occupation – Certain occupations involving repetitive movements of the joints such as squatting and bending are associated with osteoarthritis.
Nonsurgical treatments for osteoarthritis include:
- Analgesics and pain relievers
- Anti-inflammatory medicines
- Cortisone shots
- Lubrication injections of hyaluronic acid derivatives to provide some cushioning for the joint
- Physical therapy
- Assistive devices such as a cane or walker, splints, braces and shoe inserts help reduce the pain and discomfort of osteoarthritis.
If nonsurgical treatments for osteoarthritis fail to provide substantial relief, your doctor may recommend surgical procedures such as:
- Arthroscopic surgery – A minimally invasive procedure that uses very small incisions and fiber optic technology to see inside a joint and remove debris or repair torn cartilage. An arthroscope is inserted in one incision, and very thin surgical instruments are inserted in one or more of the other incisions. The arthroscope is a small tube, thinner than a pencil, containing a system of lenses, a light and a small video camera. The camera sends large real-time images to a video monitor next to the operating table, thus allowing the surgeon to make precise movements with the special surgical instruments. Thanks to the miniaturized camera, the surgeon can see more detail than could be seen with a larger incision (open surgery) and the naked eye.
- Osteotomy – Osteotomies are performed more frequently for osteoarthritis of the knee or hip. Osteotomy of the knee, for example, is a surgical procedure that involves removing a wedge of bone from one of the leg bones right below or above your knee to improve alignment of the knee joint. This may be done to relieve symptoms of trauma or osteoarthritis of the knee. A tibial osteotomy makes a cut in the shin bone (lower leg), while a femoral osteotomy makes a cut in the thigh bone. According to the National Institutes of Health, arthritis most often affects the inside part of your knee, not the outside part. That's because when you walk and stand, the inside of the knee holds more of your weight than the outside of the knee.
Osteotomy surgery works by shifting the weight away from the damaged part of your knee to the other side of the knee. When your surgeon removes a wedge of your shinbone from underneath the healthy side of your knee, the shinbone and thighbone can then bend away from the damaged cartilage. For the surgery to be successful, the side of the knee where the weight is being shifted should have little or no arthritis.
The benefits of an osteotomy are twofold: you'll be able to stay active as a result of better knee alignment and less painful symptoms of osteoarthritis. Additionally, when you have an osteotomy, you may be able to delay a total knee replacement surgery for up to 10 years.
- Total joint replacement surgery – Knee and hip joints are the most commonly replaced joints, due to their weight-bearing function. During total knee or hip replacement surgery, your orthopaedic surgeon resurfaces your joint by removing the diseased bone and cartilage. These surfaces are replaced with a metal and plastic implant, which mimics natural knee or hip motion and function. Total joint replacement surgery can help put an end to painful osteoarthritis in your knee or hip and enable you to resume a functional and active lifestyle.
- Cartilage grafting – This surgical procedure is an option for some knees or hips that have limited or contained articular cartilage loss from arthritis or trauma. Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints. Healthy cartilage makes it easier for you to move your body and allows your bones to glide over each other with very little friction. When cartilage is damaged by osteoarthritis or injury, cartilage grafts can be used to stimulate the growth of new cartilage. The benefits of cartilage grafting are pain relief and better joint function.