Osteoarthritis of the Knee
Osteoarthritis is the most common form of arthritis that affects the knee joint. It progresses gradually, and in stages. In the first stage, symptoms can be very mild, but a person suffering from the fourth stage of osteoarthritis may need surgery.
Osteoarthritis of the Knee Anatomy
Osteoarthritis affects the bones, cartilage, and synovium of the knee.
Cartilage is a slippery tissue that provides a cushion between bones and facilitates smooth joint movement. Synovium is a soft tissue that lines the joints and produces a fluid called synovial fluid for lubrication.
Osteoarthritis occurs when the synovium and cartilage break down or become rough. This leads to an overgrowth of the bone undernearth and results in pain, swelling, and difficulty moving the joint.
Osteoarthritis of the Knee Causes
The most common cause of osteoarthritis in the knee is simple: age. Though this condition can affect anyone, it is incredibly common in adults over the age of 50.
There are risk factors other than age associated with the development of OA, including:
- Previous joint injury
- Overuse of the joint
- Weak thigh muscles
- Genetic predisposition
People who already have rheumatoid arthritis are also likely to develop OA. Certain conditions like hemochromatosis and acromegaly are also associated with OA.
Osteoarthritis of the Knee Symptoms
Osteoarthritis progresses in stages, and each stage has different symptoms. There are four stages associated with osteoarthritis:
These symptoms are typically very minor or nonexistent. Though the bone has begun to grow and cartilage may be slightly damaged, the joint will appear normal on an X-ray. People with stage 1 OA very rarely experience any pain or discomfort.
This is the stage in which many people begin to notice symptoms. Symptoms that characterize this stage are chiefly stiffness and joint pain.
People with stage 3 OA in their knees will likely experience pain while engaging in regular daily activities like walking and kneeling. There may also be increased swelling due to an overproduction of synovial fluid produced when the tissue becomes inflamed.
This is the most severe stage of OA in the knee. There will be extreme pain and discomfort when moving, as well as constant swelling and stiffness.
Osteoarthritis of the Knee Diagnosis
When diagnosing OA, your doctor will ask for a family medical history as well as a history of your current symptoms. They will also likely question you about your daily activity level, and the types of medications you take.
Your doctor will also conduct a full examination of your joints to assess any places where they may be tender, painful, or swollen.
MRI scans and joint fluid tests can also reveal signs of OA. X-rays will show growth and changes in the bone.
Blood tests can be helpful in ruling out other diseases such as gout or rheumatoid arthritis.
Osteoarthritis of the Knee Treatment
Treatment will depend on the stage your OA has reached, and also how quickly it is progressing.
Over the counter pain medications are typically enough to relieve any symptoms that occur in this stage.
Performing certain exercises and stretches to improve strength and mobility can also help check the progress of OA in your knee.
The most common treatments include:
- Taking pain relievers
- Physical therapy
- A knee brace to relieve pressure on the joint
- Shoe inserts that relieve stress on the knee
Making a change to your daily activities is the most efficient way to avoid pain in this stage.
Treatments for this stage of OA can include:
- Taking over the counter pain relievers
- Taking prescription pain relievers
- Receiving corticosteroid injections directly in the knee
A doctor can administer up to 5 injections of hyaluronic acid over the course of a few weeks. Though this treatment is controversial, it can provide relief for up to 6 months after being administered.
At this stage, surgery is likely the only option. Orthopedic surgery can be performed to completely replace the knee joint, or to realign the joint.
Osteoarthritis of the Knee Prevention
There are several changes you can make to your lifestyle that may help prevent OA from developing, or keep it from advancing further. Some of these lifestyle changes include:
- Maintaining a healthful weight. Excess weight places extra pressure on the knees. Extra fat in the body can also prompt it to produce a type of protein called cytokines. This can affect the cartilage and lead to widespread inflammation.
- Controlling blood sugar. High glucose levels can affect the structure of cartilage.
- Exercising regularly. Moderate exercise helps the joints stay flexible and strengthens the muscles that support the joints.
- Reducing the risk of injury. Any cartilage that has suffered damage is more likely to develop arthritis later. Using protective gear when you play sports and wearing shoes that fit can help reduce the risk of injuring the cartilage in your knee.
- Undergoing posture and bone alignment tests. Doctors have tests that can assess the alignment of your bones, and your posture as it relates to the way you walk. A better understanding of these functions of your body can help your doctors prevent OA from progressing.
- Avoiding overuse. People who regularly lift more than 55 pounds have an increased risk of OA. Varying activities that involve heavy lifting or involve repetitive motions of the knee joint can help keep OA from progressing.