The word arthritis actually means joint inflammation of one or more joints in your body. As a load-bearing joint the knee joint is commonly affected. Knee arthritis can make everyday activities such as walking or climbing stairs troublesome. It is a major cause of absence from work and a serious disability for many people.
- Osteoarthritis is the most common type and affects everyone to a greater or lesser extent, depending on age and prolonged and regular activity.
- The other type is called Rheumatoid arthritis of which there are 100 different types.
- While arthritis is mainly an adult disease, some forms affect children.
- Typically, these conditions are characterized by pain and stiffness in and around one or more joints. The symptoms can develop gradually or suddenly. Certain rheumatic conditions can also involve the immune system and various internal organs of the body.
- Although there is no cure for arthritis, there are many treatment options available to help manage pain and keep people staying active.
A normal looking knee joint
- The knee is the largest and strongest joint in your body.
- It is made up of the lower end of the femur (thigh bone), the upper end of the tibia (shin bone), and the patella (kneecap).
- Where these bones meet, they are covered with a kind of smooth, slippery substance that protects and cushions the bones as you bend and straighten your knee. This is called as the articular / hyaline cartilage.
- Within the knee there are two rings of a different type of cartilage that act as a shock absorbers between the end of thigh bone (femur) and the beginning of shinbone (Tibia). These are called the lateral meniscus and the medial meniscus.
- The whole of the joint is surrounded by a capsule which has the synovial membrane on its inside surface. This membrane releases a fluid that lubricates the cartilage and reduces friction.
Arthritis – the Major types
The major types of arthritis that affect the knee are osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis
- Osteoarthritis is the most common form of arthritis in the knee. It is a degenerative, "wear-and-tear" type of arthritis that occurs most often in people 50 years of age and older, but may occur in younger people, too.
- In osteoarthritis, the cartilage in the knee joint gradually dries out, cracks and wears away. As the cartilage wears away, it becomes frayed and rough, and the protective space between the bones decreases. This can result in bone rubbing on bone, and produce painful bone spurs. Osteoarthritis develops slowly and the pain it causes worsens over time.
- This must not be confused with osteoarthritis. RA (Rheumatoid Arthritis) affects multiple joints and it is symmetrical in nature, meaning it usually affects same joint on both sides of the body.
- RA is an autoimmune disorder, which means that our immune system attacks its own tissues and damages the cartilage and ligaments leading to arthritic changes at the joint.
- Post-traumatic arthritis is a form of arthritis that develops after an injury to the knee. This may happen after a broken bone which alters the normal movement in the joint.
- This may result in undue friction stress at the knee joint affecting mobility. Over time this undue stress may result in increased wear an tear leading to arthritis.
- This may also be caused by damage to the meniscus and the ligaments, which over time may result in increased wear and tear leading to arthritis at the joint.
What are the symptoms of knee OA?
- A knee joint affected by arthritis may be painful and inflamed.
- The pain develops gradually over time, although sudden onset is also possible.
- The joint may become stiff and swollen, making it difficult to bend and straighten the knee.
- Pain and swelling may be worse in the morning, or after sitting or resting.
- Vigorous activity may cause pain to flare up.
- Loose fragments of cartilage and other tissue can interfere with the smooth motion of joints. The knee may "lock" or "stick" during movement. It may creak, click, snap or make a grinding noise (crepitus).
- Pain may cause a feeling of weakness or buckling in the knee.
- Many people with arthritis note increased joint pain with rainy weather.
When you see a specialist they will be looking for the following:
- Joint swelling, warmth, or redness & tenderness about the knee
- Range of passive (assisted) and active (self-directed) motion
- Instability of the joint
- Crepitus (a grating sensation inside the joint) with movement
- Pain when weight is placed on the knee
- Problems with your gait (the way you walk)
- Any signs of injury to the muscles, tendons, and ligaments surrounding the knee
- Involvement of other joints (an indication of rheumatoid arthritis)
- X-rays. These imaging tests create detailed pictures of dense structures, like bone. They can help distinguish between various forms of arthritis. X-rays of an arthritic knee may show a narrowing of the joint space, changes in the bone and the formation of bone spurs (osteophytes).
- Other tests. Occasionally, a magnetic resonance imaging (MRI) scan, a computed tomography (CT) scan, or a bone scan may be needed to determine the condition of the bone and soft tissues of your knee.
- Laboratory Tests: Your doctor may also recommend blood tests to determine which type of arthritis you have. With some types of arthritis, including rheumatoid arthritis, blood tests will help with a proper diagnosis.
(Left) In this x-ray of a normal knee, the space between the bones indicates healthy cartilage (arrows). (Right) This x-ray of an arthritic knee shows severe loss of joint space.
What are the Treatments available for Knee OA?
There is no cure for arthritis but there are a number of treatments that may help relieve the pain and disability it can cause.
Nonsurgical Treatment : As with other arthritic conditions, the initial treatment of arthritis of the knee is nonsurgical. Your doctor may recommend a range of treatment options.
- Some changes in your daily life can protect your knee joint and slow the progress of arthritis.
- Minimize activities that aggravate the condition, such as climbing stairs.
- Switching from high impact activities (like jogging or tennis) to lower impact activities (like swimming or cycling) will put less stress on your knee.
- Losing weight can reduce stress on the knee joint, resulting in less pain and increased function.
- It's very important to keep your joints moving. You need to find the right balance between rest and exercise – little and often is usually the best approach. There are two types of exercise that you'll need to do:
- Aerobic exercise: Exercise that increases your pulse rate and makes you short of breath helps you sleep better, is good for your general health and can reduce pain.
- Strengthening exercises: These improve the strength and tone of the muscles that control your knee and help to stabilise and protect your knee joint. They can reduce pain can and stop your knee giving way and so reduce your risk of falling.
- A physiotherapist can advise you on the best exercises to do, but you'll need to build them into your daily routine to get the most benefit from them.
- Swimming is very good for people with osteoarthritis because the water supports your weight, so you won't put a lot of strain on your joints. Hydrotherapy (exercises in a warm water) can help get muscles and joints working, and it can be very relaxing.
- If you know you're going to be more active than usual, try taking a painkiller before you start to avoid increased pain later.
- Using devices such as a cane, wearing shock-absorbing shoes or inserts, or wearing a brace or knee sleeve can be helpful.
- A brace assists with stability and function, and may be especially helpful if the arthritis is centered on one side of the knee.
- There are two types of braces that are often used for knee arthritis: An "unloader" brace shifts weight away from the affected portion of the knee, while a "support" brace helps support the entire knee load.
Applying heat or ice, using pain-relieving ointments or creams, or wearing elastic bandages to provide support to the knee may provide some relief from pain.
Several types of drugs are useful in treating arthritis of the knee. Because people respond differently to medications, your doctor will work closely with you to determine the medications and dosages that are safe and effective for you.
- Simple pain relievers such as paracetamol are usually the first choice of therapy for arthritis of the knee. These over-the-counter pain reliever that can be effective in reducing arthritis pain. Like all medications, over-the-counter pain relievers can cause side effects and interact with other medications you are taking. Be sure to discuss potential side effects with your chemist.
- Non-steroidal anti-inflammatory drugs or NSAIDs areanother type of pain reliever, such as ibuprofen and naproxen, and are available both over-the-counter and by prescription.
- Corticosteroids (also known as cortisone) are powerful anti-inflammatory agents that can be injected into the joint. These injections provide pain relief and reduce inflammation; however, the effects do not last indefinitely. Usually these injections are limited to 3 per year to a joint, due to possible side effects. In some cases, pain and swelling may "flare" immediately after the injection, and the potential exists for long-term joint damage or infection. With frequent repeated injections, or injections over an extended period of time, joint damage can actually increase rather than decrease.
- Disease-modifying anti-rheumatic drugs (DMARDs) are used to slow the progression of rheumatoid arthritis. Drugs like methotrexate, sulfasalazine, and hydroxychloroquine are commonly prescribed. In addition, biologic DMARDs like etanercept (Embril) and adalimumab (Humira) may reduce the body's overactive immune response. Because there are many different drugs today for rheumatoid arthritis, a rheumatology specialist is often required to effectively manage medications.
- Hyaluronan injections. Hyaluronan injections are used to treat osteoarthritis.
- Glucosamine and chondroitin sulfate, substances found naturally in joint cartilage, can be taken as dietary supplements. Although patient reports indicate that these supplements may relieve pain, there is no evidence to support the use of glucosamine and chondroitin sulfate to decrease or reverse the progression of arthritis.
- Many alternative forms of therapy are unproven, but may be helpful to try, provided you find a qualified practitioner and keep your GP informed of your decision. These include the use of acupuncture and magnetic pulse therapy.
- Acupuncture uses fine needles to stimulate specific body areas to relieve pain or temporarily numb an area. Although it is used in many parts of the world and evidence suggests that it can help ease the pain of arthritis, there are few scientific studies of its effectiveness. Be sure your acupuncturist is certified, and do not hesitate to ask about his or her sterilization practices. In the NHS Acupuncture is practiced by many physiotherapists, doctors and other health care professionals. Please ask your health care provider for more details.
Your specialist doctor or Physiotherapist may recommend for surgery if your pain from arthritis causes disability and is not relieved with nonsurgical treatment. As with all surgeries, there are some risks and possible complications with different knee procedures. Your surgeon will discuss the possible complications with you before your operation.
- Arthroscopy: During arthroscopy, surgeons use small incisions and thin instruments to diagnose and treat joint problems. Arthroscopic surgery is not frequently used to treat arthritis of the knee. In cases where osteoarthritis is accompanied by a degenerative cartilage tear, arthroscopic surgery may be recommended to treat the torn meniscus.
- Cartilage grafting: Normal, healthy cartilage tissue may be taken from another part of the knee or from a tissue bank to fill a hole in the articular cartilage. This procedure is typically considered only for younger patients who have small areas of cartilage damage.
- Synovectomy: The joint lining damaged by rheumatoid arthritis is removed to reduce pain and swelling.
- Osteotomy: In a knee osteotomy, either the tibia (shinbone) or femur (thighbone) is cut and then reshaped to relieve pressure on the knee joint. Knee osteotomy is used when you have early-stage osteoarthritis that has damaged just one side of the knee joint. By shifting your weight off the damaged side of the joint, an osteotomy can relieve pain and significantly improve function in your arthritic knee.
- Total or partial knee replacement (arthroplasty): Your doctor will remove the damaged cartilage and bone, and then position new metal or plastic joint surfaces to restore the function of your knee.
(Left) A partial knee replacement is an option when damage is limited to just one part of the knee. (Right) A total knee replacement prosthesis.
- After any type of surgery for arthritis of the knee, there is a period of recovery. Recovery time and rehabilitation depends on the type of surgery performed.
- Your doctor may recommend physiotherapy to help you regain strength in your knee and to restore range of motion.
- Depending upon your procedure, you may need to wear a knee brace, or use crutches or a cane for a time.
- In most cases, surgery relieves pain and makes it possible to perform daily activities more easily.