Key Takeaways
- Knee arthritis can seriously affect mobility and quality of life.
- There are three types of knee arthritis: osteoarthritis, rheumatoid arthritis and post-traumatic arthritis.
- Activity modification and medicines can help ease the pain and swelling of knee arthritis.
- Surgery is the last option for the treatment of knee arthritis.
Sixty-nine-year-old Mary Anne Laporte was diagnosed with knee arthritis 15 years ago. For years, she kept the pain under control with steroid injections and physical therapy, but when she began to barely be able to walk, she knew it was time for knee replacement surgery.
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Under the care of Dr. Lucas Nikkel, assistant professor of orthopedic surgery at Johns Hopkins School of Medicine in Baltimore, Laporte has undergone surgeries on each of her knees, both in the last year.
“I’ve had the easiest surgical experience of anyone I know because I prepared myself well with physical therapy and was given the proper information needed for a quick and successful recovery,” she says. “Now, I can again do the things I haven’t been able to for a long time.”
Here's what you need to know about knee arthritis, including signs and symptoms, risk factors, diagnosis and treatment options.
Your knees are the largest and strongest joints in the body and one of the most common joints to be affected by arthritis.
They’re made up of the lower end of the thighbone (femur), the upper end of the shinbone (tibia) and the kneecap (patella). The ends of these three bones form the knee joints that are covered with cartilage, a smooth slippery substance that protects and cushions the bones as you bend or straighten your legs.
There are three main kinds of knee arthritis:
- Degenerative (osteoarthritis). Osteoarthritis is the most common form of knee arthritis. According to Dr. Matthew Hepinstall, associate professor of orthopedic surgery at NYU Langone Health in New York, well over 90% of knee arthritis is osteoarthritis.
- Inflammatory (rheumatoid arthritis). Also common, rheumatoid arthritis is a chronic autoimmune disease that causes pain, swelling and stiffness.
- Post-traumatic arthritis. This is inflammation of the joint that forms after a trauma to the knee.
Knee arthritis usually develops slowly, with pain increasing over time, but it can occasionally progress more rapidly when the cartilage between the bones wears away. When the condition advances, bones rub against bones, which causes pain, stiffness, swelling, inflammation and limited motion.
As damage to the knee progresses, knee arthritis can seriously affect mobility and quality of life and can make daily activities and movement – like walking and climbing stairs – difficult.
Although the exact cause of knee arthritis is unknown, there are certain risk factors that could increase your chances of developing the condition, including:
- Age. Although knee arthritis can occur at any age, it becomes more common as people get older, especially over the age of 50.
- Bone anomalies or deformities. If the lower limbs are crooked (bow-legged or knock-kneed), the risk for knee arthritis is higher.
- Injury. Certain injuries, like ACL or meniscus tears, can eventually lead to knee arthritis.
- Stress on the knee. Running, playing sports or working a physically demanding job may increase risk, but this is controversial.
- Weight. Carrying excess weight can put stress on the knees. Fat cells also make proteins that cause inflammation in and around joints.
- Genetics. A family history of knee arthritis is a risk factor. Experts have identified genes associated with arthritis risk.
- Gender. Women are more likely than men to develop arthritis.
- Metabolic diseases. Some diseases – like diabetes and hemochromatosis, a condition in which the blood has too much iron – have been linked to arthritis.
Because knee arthritis is a progressive condition, people become symptomatic at different times and experience varying levels of pain.
"Some may be in little or no pain, while others may experience a tremendous amount of pain," Nikkel says.
- Pain. Knee arthritis pain can be exacerbated by certain movements and may make it difficult to bend or straighten the knee. When knee arthritis is severe, loading the knee joints with walking long distances, standing for long periods of time and climbing stairs can make the pain worse. Change of weather can also increase or reduce pain. At its most severe, knee arthritis pain can be felt even when just sitting or lying down.
- Stiffness and swelling. Knee and joint stiffness make it difficult to bend or straighten the knee.
- Catching and locking. Loose fragments of cartilage and other tissue can interfere with smooth movement of the knee, causing these joints to catch and lock.
- Crepitus. Cracking, crunching, clicking and snapping sounds can be heard when moving an arthritic knee.
- Weakness. Knee arthritis may reduce movement, making joints weaker and worsening symptoms.
When knee pain interferes with your daily activities, it may be time to talk to your primary care doctor or see a specialist such as an orthopedist or rheumatologist.
If you’ve had an injury to your knee or you’re experiencing knee pain, swelling, tenderness or difficulty in moving your knee, you should make an appointment to see an orthopedist, a type of doctor who specializes in injuries of the musculoskeletal system.
Some orthopedists specialize exclusively in the knees and the diagnosis and treatment of its bones, muscles and joints.
- Physical exam. An orthopedist will ask about previous injuries or surgeries to the knee. To determine the joint’s flexibility, range of motion and to listen for popping noises, the doctor will move the knee. He may put pressure on it to test for tenderness and may examine the hip joints by asking you to walk.
- Blood tests. While there are no blood tests for osteoarthritis, they can help rule out other forms of arthritis, such as rheumatoid arthritis.
- Joint aspiration. A needle may be used to draw fluid from the knee to be tested for inflammation to determine whether pain is caused by gout or an infection and not arthritis,
- X-ray. An x-ray will show detailed images of the knee joint. A healthy knee joint shows a gap between the bones where the cartilage serves as cushion between the femur and tibia. When the gap between the bones in the knee is narrowed, it’s evidence of arthritis. The less cartilage between the bones, the more pain will be felt. An x-ray may also show bone spurs caused by the joint damage linked to arthritis.
Other diagnostic imaging tests, such as MRI and CT scans, are normally not needed to make a diagnosis.
Treatment for knee arthritis depends on the types and stages of the condition, as well as the patient’s age and severity of pain. Although cartilage loss can’t be reversed, doctors can help reduce or manage pain and prevent further damage.
Surgery is reserved for relatively advanced cases and is typically the last treatment option.
Lifestyle modifications and management
Experts often encourage patients to first incorporate lifestyle modifications and supportive activities to manage and alleviate pain from knee arthritis before exploring pharmacological and surgical options.
“No treatment has been proven to cure or delay progression of knee arthritis, but physical therapy and lifestyle changes – such as decreasing weight and impact on the knees – can help our patients live well with the condition,” Hepinstall says.
- Activity modification. Exercise can help people keep physically active and manage symptoms of knee arthritis. The best exercises for osteoarthritis are low impact – like swimming and cycling – instead of high-impact activities, like running, jumping or playing tennis. In addition to keeping pressure off the knees, physical therapy can help strengthen muscles and improve range of motion and flexibility. The Arthritis Foundation recommends 150 minutes of exercise a week.
- Follow a healthy diet. Certain foods – such as simple carbs and foods high in saturated fat, sugar and sodium – have been shown to worsen inflammation and chronic pain from arthritis. Knowing what foods to avoid with arthritis is just as important as knowing what foods to eat more of. In fact, research shows that the Mediterranean diet – which emphasizes fruits, vegetables, whole grains, beans, fish and healthy fats – can significantly reduce symptoms of arthritis.
- Lose any extra weight. Carrying extra weight puts pressure on the joints. To reduce stress on the joints, be sure to maintain a healthy weight.
- Apply heat or ice. Heat may relieve aches and stiffness, while cold may ease swelling and pain.
- Assistive devices. Canes, knee sleeves and braces can help with support for the knee.
Medications
If lifestyle changes aren’t giving enough relief from pain and discomfort, certain drugs – including over-the-counter arthritis pain relievers – may be the next step to help patients reduce pain and inflammation enough so that they can incorporate lifestyle changes into their routines.
- Nonsteroidal anti-inflammatory drugs (NSAIDs). OTC NSAIDs – like aspirin, ibuprofen (Advil, Aleve and Motrin) and naproxen (Aleve) – are usually the first choice for medication treatment for knee arthritis. These drugs may also come in more potent prescription forms.
- Acetaminophen. These are simple OTC painkillers – like Tylenol and Excedrin – that can reduce arthritis pain, especially for people who can’t take NSAIDs.
- COX-2 inhibitor. This is a type of NSAID that treats the pain and inflammation of arthritis but causes fewer stomach and intestinal problems than other NSAIDs. Celecoxib (Celebrex) is the only COX-2 inhibitor available in the United States and is available by prescription only.
- Corticosteroids (cortisone). This is a powerful anti-inflammatory drug that comes in cream or can be injected into the knee joints to provide pain relief and reduce inflammation. A doctor may order an injection three to four times a year, but it can’t be used indefinitely. Pain and swelling may flare after injection.
- Disease modifying antirheumatoid drugs (DMARDs). These drugs may be used to slow the progression of rheumatoid arthritis in the knee. They reduce pain and inflammation, reduce tissue damage and slow disease. Methotrexate is usually the first of this group of drugs prescribed by physicians.
- Glucosamine and chondroitin sulfate. These are substances that can be found naturally in joint cartilages and can be taken as a dietary supplement to reduce pain. Be aware that the Food and Drug Administration does not test dietary supplements, and studies have not definitively shown clear evidence to support any benefit of using glucosamine and chondroitin sulfate as joint supplements.
- Alternative treatments. Acupuncture, magnetic pulse therapy, platelet-rich plasma, stem cell, hyaluronic acid injections and other alternative treatments may be helpful, but they have not been proven to be effective for knee arthritis.
Because medications can have negative effects, such as fatigue, and may have negative interactions, never take any drug without consulting with your doctor.
Surgical treatments
If knee arthritis isn’t responding well to lifestyle modifications and medications, doctors can perform surgery to restore function, mobility and quality of life.
- Total knee replacement. This common orthopedic surgical procedure is the gold standard for treating knee arthritis with surgery. The ends of the bones of the knee are removed and replaced with a combination of metal and plastic. Total knee replacement provides 90% to 95% pain relief and has only a 1% to 2% complication rate, according to the Association of Hip and Knee Surgeons. Advances in knee replacement surgery have gotten better, allowing replacement knees to typically last for 20 years or more. For most people with severe arthritis, they can last a lifetime.
- Partial knee replacement. When arthritis is confined to one part of the knee and there is still good knee motion, a surgeon can replace only the part of the knee that’s worn out. This may either be the inner part of the joint between the femur and shinbone, the outer part of the joint or the joint between the kneecap and the femur. Compared to total knee replacement, potential benefits include a faster recovery and a more normal-feeling knee. However, the durability is not as long as a total knee replacement, and it’s relatively common to need more surgery within an average of 15 years. Additionally, experts say that fewer than 15% of patients who need knee replacement are typically considered to be candidates for partial replacements.
- Osteotomy. This procedure involves cutting the bone and reorienting the knee alignment. This isn’t the best treatment for patients with knee arthritis. It’s typically reserved for younger patients with significant deformity and less severe arthritis.
- Cartilage restoration. Attempts to harvest cartilage cells and replace them in the knee are appealing in theory, but these surgeries don’t work in cases of severe arthritis. They’re reserved for specific situations with relatively small cartilage defects. Outcomes are not as reliable or durable as they are with knee replacement surgery.
- Arthroscopy. In this procedure, a surgeon makes small incisions in the knee, inserts a camera to look inside the knee and uses small instruments to clean it out or remove loose pieces of cartilage. However, while arthroscopy is sometimes performed to address meniscus or other cartilage tears in patients with mild arthritis, this procedure is no longer recommended for advanced arthritis. According to the Arthritis Foundation, studies have shown that arthroscopy only provides short-term relief or no relief at all.
Recovery from knee replacement surgery and other surgical treatments for knee arthritis can be long and arduous. During the first and second months, your condition may feel worse before it gets better, Hepinstall says. However, by the third and fourth months, many patients note significant improvement in pain and function.
“You will do well with this surgery if you follow a structured recovery program working with your doctor and a physical therapist, but you must understand that recovery takes a few months and your knee may take up to a full year to be as good as it can get,” Hepinstall says.
