Knee pain is a common reason that people visit their doctors' offices or the emergency room. Often, knee pain is the result of an injury, such as a ruptured ligament or torn cartilage. But some medical conditions can also bring you to your knees, including arthritis, gout and infections.
Depending on the type and severity of damage, knee pain can be a minor annoyance, causing an occasional twinge when you kneel down or exercise strenuously. Or knee pain can lead to severe discomfort and disability.
Many relatively minor instances of knee pain respond well to self-care measures. More serious injuries, such as a ruptured ligament or tendon, may require surgical repair.
Although every knee problem can't be prevented — especially if you're active — you can take certain steps to reduce the risk of injury or diseaseThe key to treating many types of knee pain is to break the cycle of inflammation that begins right after an injury. Even minor trauma causes your body to release substances that lead to inflammation. The inflammation itself causes further damage, which in turn triggers more inflammation, and so on. But a few simple self-care measures can be remarkably effective in ending this cycle. For best results, start treating your injury right away and continue for at least 48 hours.
Commonly referred to by the acronym P.R.I.C.E., self-care measures for an injured knee include:
Protection. The best way to protect your knee from further damage depends on the type and severity of your injury. For most minor injuries, a compression wrap is usually sufficient. More serious injuries, such as a torn ACL or high-grade collateral ligament sprain usually require crutches and sometimes also a brace to help stabilize the joint with weight bearing.
Rest. Taking a break from your normal activities reduces repetitive strain on your knee, gives the injury time to heal and helps prevent further damage. Minor injuries may require only a day or two of rest, but severe damage is likely to need a longer recovery time.
Ice. A staple for most acute injuries, ice reduces both pain and inflammation. Some doctors recommend applying ice to your injured knee for 15 to 20 minutes three times a day. A bag of frozen peas works well because it covers your whole knee. You can also use an ice pack wrapped in thin fabric to protect your skin. Although ice therapy is generally safe and effective, don't leave ice on longer than recommended because of the risk of damage to your nerves and skin. After two days, you might try switching to heat to relax your muscles and increase blood flow.
Compression. This helps prevent fluid buildup (edema) in damaged tissues and maintains knee alignment and stability. Look for a compression bandage that's lightweight, breathable and self-adhesive. It should be tight enough to support your knee without interfering with circulation.
Elevation. Because gravity drains away fluids that might otherwise accumulate after an injury, elevating your knee can help reduce swelling. Try propping your injured leg on pillows or sitting in a recliner.
Anti-inflammatory medications
Nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, ibuprofen (Advil, Motrin, others) and naproxen sodium (Aleve, Naprosyn), can help relieve pain. But if taken immediately after an injury, they may actually increase swelling. What's more, NSAIDs can have side effects, especially if you take them for long periods or in amounts greater than the recommended dosage. Even small doses may cause nausea, stomach pain, stomach bleeding or ulcers; and large doses can lead to kidney problems and fluid retention.
NSAIDs also have a ceiling effect, which means there's a limit to how much pain they can control. If you have moderate to severe pain, exceeding the dosage limit probably won't relieve your symptoms. Taking two different NSAIDs at the same time also won't provide more relief and may increase your risk of side effects.
When self-care measures aren't enough to control pain and swelling and promote healing in an injured knee, your doctor may recommend other options, including:
Physical therapy
Normally, the goal of physical therapy is to strengthen the muscles around your knee and help you regain knee stability. Depending on your injury, training is likely to focus on the muscles in the back of your thigh (hamstrings), the muscles on the front of your thigh (quadriceps), and your calf, hip and ankle. You can do some exercises at home. Others require the use of weight machines, exercise bicycles or treadmills, which may mean visits to an athletic club, fitness center or clinic.
In the early stages of rehabilitation, you work on re-establishing full range of motion in your knee. You then progress to knee-, hip- and ankle-strengthening exercises combined with training to improve your stability and balance. Finally, you work on training specific to your sport or work activities, including exercises to help you prevent further injury.
Depending on the type of injury, you can expect to be back to your normal daily activities in as little as two to four weeks. But to maintain maximum knee stability, you'll need to follow an exercise program for your legs two to three days a week.
Surgical options
There's no single best way to treat most knee injuries. Whether surgical treatment is right for you depends on many factors, including:
The type of injury and amount of damage to your knee
The risk of future injury or damage if you don't have surgery
Your lifestyle, including which sports you play
Your willingness to modify your activities and sports
Your motivation to work through rehabilitation to strengthen your knee after surgery
If you have an injury that may require surgery, it's usually not necessary to have the operation immediately. In most cases, you'll do better if you wait until the swelling goes down and you regain strength and full range of motion in your knee.
Before making any decision, consider the pros and cons of both nonsurgical rehabilitation and surgical reconstruction in relation to what's most important to you. Nonsurgical treatment isn't an option if you have cartilage damage that interferes with your range of motion (locked knee) or if the blood supply to your knee is severely compromised.
If you choose to have surgery, your options may include:
Arthroscopic surgery. Depending on the nature of your injury, your doctor may be able to examine and repair your joint damage using an arthroscopic technique (arthroscopy) that requires just a few small incisions. Arthroscopy may be used to remove loose bodies from your knee joint, repair torn or damaged cartilage, reconstruct torn ligaments and occasionally correct damage from degenerative joint diseases such as arthritis.
The advantage of the procedure is that you're likely to recover more quickly and with less discomfort than you would with open surgery. Even so, recovery from ligament and meniscus surgery is often slow and requires a strong commitment to physical therapy.
Partial knee replacement surgery. If you have considerable knee damage from degenerative arthritis but still retain some healthy cartilage, and conservative measures such as lifestyle changes, medication and physical therapy fail to help your symptoms, you may be a candidate for a partial knee replacement.
In this procedure (unicompartmental arthroplasty), your surgeon replaces only the most damaged portion of your knee with a prosthesis made of metal and plastic. The surgery can usually be performed with a small incision, and your hospital stay is typically just one night. You're also likely to heal more quickly than you are with surgery to replace your entire knee. Unfortunately, many people who opt for knee replacement surgery have damage too extensive for unicompartmental arthroplasty. In addition, long-term results may not be as good as they are with a total knee replacement.
Total knee replacement. In this procedure (total knee arthroplasty), your surgeon cuts away damaged bone and cartilage from your thighbone, shinbone and kneecap, and replaces it with an artificial joint (prostheses) made of metal alloys, high-grade plastics and polymers. Total knee arthroplasty can improve knee problems associated with osteoarthritis, rheumatoid arthritis and other degenerative conditions such as osteonecrosis — a condition in which obstructed blood flow causes your bone tissue to die.
You may be a candidate for total knee replacement if you have a severely damaged, arthritic knee that limits your mobility and function, you're older than 55 and in generally good health, and conservative measures fail to improve your symptoms.
Other options
In recent years, a number of nonsurgical treatments for knee pain that results from arthritis have been investigated or become available. Some are in the experimental stage, and others are used fairly routinely to control pain and inflammation. They include:
Orthotics and bracing. Arch supports, sometimes with wedges on the inner or outer aspect of the heel, can help to shift pressure away from the side of the knee most affected by osteoarthritis. A brace called an "unloader" brace also may be used to help ease the pressure on the most arthritic side of the knee.
Glucosamine and chondroitin. These substances, found naturally in cartilage, are also available as over-the-counter dietary supplements. Both may help relieve the pain of osteoarthritis of the knee. Unlike traditional anti-inflammatory drugs, which simply reduce inflammation, glucosamine appears to decrease the rate of cartilage destruction. A major, federally sponsored study of these substances is under way.
Corticosteroid injections. Injections of a corticosteroid drug into your knee joint may help reduce the symptoms of an arthritis flare and provide pain relief that lasts a few months. You usually must wait at least four months between injections. The injections aren't effective in all cases and cause some of the same side effects that oral steroid medications do, including an increased risk of infection, water retention and elevated blood sugar levels.
Hyaluronic acid. This thick fluid is normally found in healthy joints, and injecting it into damaged ones may ease pain and provide lubrication. Injected hyaluronic acid, which is derived from rooster combs, was first used in the 1970s to treat arthritis in racehorses. The Food and Drug Administration (FDA) approved it for human use in 1997. Experts aren't quite sure how hyaluronic acid works, but it may reduce inflammation. Relief from a series of shots may last as long as six months.
Topical painkillers. Applying certain ointments to your skin may help relieve the pain and stiffness of osteoarthritis. A study published in the April 2004 issue of "Rheumatology" reported that a cream called Celadrin, which contains cetylated fatty acids, greatly improved mobility and function in people with osteoarthritis of the knee. The effects were apparent within 30 minutes of applying the cream. In another study, a lidocaine patch applied to arthritic knees provided significant pain relief. Neither treatment has been approved for treating knee pain, however. But the FDA has approved another over-the-counter product, capsaicin, for the temporary relief of arthritis pain. It's sold under several names, and many pharmacies also carry their own brands.
In countries other than the United States, doctors often prescribe topical NSAIDs for relief of chronic musculoskeletal conditions such as arthritis and tendinitis. A systematic review of treatment with NSAID creams found that they were as effective as oral medications but without the serious side effects.