Knee Problems:What to do about them and how to prevent them

What Causes Knee Problems?

Knee problems can be the result of disease or injury.

Disease

A number of diseases can affect the knee. The most common is arthritis. Although arthritis technically means “joint inflammation,” the term is used loosely to describe many different diseases that can affect the joints. Some of the most common forms of arthritis and their effects on the knees are described a bit later in this booklet.

Injury

Knee injuries can occur as the result of a direct blow or sudden movements that strain the knee beyond its normal range of motion. Sometimes knees are injured slowly over time. Problems with the hips or feet, for example, can cause you to walk awkwardly, which throw off the alignment of the knees and leads to damage. Knee problems can also be the result of a lifetime of normal wear and tear. Much like the treads on a tire, the joint simply wears out over time. This booklet discusses some of the most common knee injuries, but first describes the structure of the knee joint.

Total Knee Replacement

Total knee replacement is often the answer for people when x rays and other tests show joint damage; when moderate-to-severe, persistent pain does not improve adequately with nonsurgical treatment; and when the limited range of motion in their knee joint diminishes their quality of life.

First made available in the late 1950s, early total knee replacements did a poor job of mimicking the natural motion of the knee. For that reason, these procedures resulted in high failure and complication rates. Advances in total knee replacement technology in the past 10 to 15 years have enhanced the design and fit of knee implants.

The new joint, called a prosthesis, can be made of plastic, metal, or both. It may be cemented into place or uncemented. An uncemented prosthesis is designed so that bones will grow into it.

In the past, patients between 60 and 75 years of age were considered to be the best candidates for total knee replacement. Over the past two decades, however, that age range has broadened to include more patients older than 75, who are likely to have other health issues, and patients younger than 60, who are generally more physically active and whose implants will probably be exposed to greater mechanical stress.

About 90 percent of patients appear to experience rapid and substantial reduction in pain, feel better in general, and enjoy improved joint function. Although most total knee replacement surgeries are successful, failure does occur and revision is sometimes necessary. Risk factors include being younger than 55 years old, being male, being obese, and having osteoarthritis, infection, or other illnesses.

How to prevent knee problems

Some knee problems, such as those resulting from an accident, cannot be foreseen or prevented. However, people can prevent many knee problems by following these suggestions:

• Before exercising or participating in sports, warm up by walking or riding a stationary bicycle, then do stretches. Stretching the muscles in the front of the thigh (quadriceps) and back of the thigh (hamstrings) reduces tension on the tendons and relieves pressure on the knee during activity.
• Strengthen the leg muscles by doing specific exercises (for example, by walking up stairs or hills or by riding a stationary bicycle). A supervised workout with weights is another way to strengthen the leg muscles that support the knee.
• Avoid sudden changes in the intensity of exercise. Increase the force or duration of activity gradually.
• Wear shoes that fit properly and are in good condition. This will help maintain balance and leg alignment when walking or running. Flat feet or overpronated feet (feet that roll inward) can cause knee problems. People can often reduce some of these problems by wearing special shoe inserts (orthotics).
• Maintain a healthy weight to reduce stress on the knee. Obesity increases the risk of osteoarthritis of the knee.

The best types of exercise for people with knee problems

If you already have knee problems, your doctor or physical therapist can help with a plan of exercise that will help the knee(s) without increasing the risk of injury or further damage. As a general rule, you should choose gentle exercises such as swimming, aquatic exercise, or walking rather than jarring exercises such as jogging or high-impact aerobics. Here are three types of exercise that have helped others with knee problems:

• Range-of-motion exercises to help maintain normal joint movement and relieve stiffness.
• Strengthening exercises to help keep or increase muscle strength. Keeping muscles strong with exercises, such as walking up stairs, doing leg lifts or dips, or riding a stationary bicycle, helps support and protect the knee.
• Aerobic or endurance exercises to improve function of the heart and circulation and to help control weight. Weight control can be important to people who have arthritis because extra weight puts pressure on many joints. Some studies show that aerobic exercise can reduce inflammation in some joints.

-- Information from National Institute of Arthritis and Musculoskeletal and Skin Diseases