What is knee arthritis?
Knee arthritis occurs when the cartilage of the knee joint gradually erodes. Cartilage is a rubbery tissue that allows bones to glide smoothly over one another. Without the cushioning effect of cartilage, the bones of the knee joint rub together. The knee can't move easily and becomes stiff, swollen and painful.
There are several different types of knee arthritis:
- Osteoarthritis is the most common form. Also called "wear and tear" arthritis, it is a progressive, degenerative disease in which the surface layer of cartilage slowly wears away. Osteoarthritis is especially prevalent among middle-aged and older adults. Obesity and genetics are also contributing factors.
- Rheumatoid arthritis is an inflammatory condition that can destroy joint cartilage. It can occur at any age and generally affects both knees.
- Post-traumatic arthritis can develop after an injury to the knee. It is similar to osteoarthritis and may result from a fracture, ligament injury or meniscus tear.
A healthy knee
An osteoarthitic knee
What are the symptoms of knee arthritis?
Common early symptoms include aching joints after physical activity or stiffness first thing in the morning. The pain may cause a feeling of weakness in the knee, resulting in locking or buckling. Generally, the pain associated with knee arthritis develops gradually. With time, symptoms may occur more often, making it difficult to bend or straighten the knee. It can become harder to walk, climb stairs or get in and out of the car. Worsening knee arthritis can interfere with daily activities and impact your quality of life.
How is knee arthritis diagnosed?
In addition to a physical exam, your doctor can use specific tests, including X-ray and MRI, to diagnose knee arthritis.
Normal joint space between the femur and tibia.
Decreased joint space due to damaged cartilage and bone spurs.
What is the treatment?
There is no cure for knee arthritis, but treatment can help slow its progression, reduce pain and increase function.
Patients are encouraged to try these non-operative options first:
- Weight loss
Simple weight loss can reduce stress on the knee. If you're overweight, losing just five percent of your current weight can improve your arthritis symptoms.
- Exercise/Physical therapy
Low-impact exercise, in addition to weight loss if indicated, is the most effective non-operative method at controlling symptoms related to knee osteoarthritis. Exercise is important to lubricate the knee joint, strengthen surrounding muscles, maintain bone strength and control weight. Non-impact exercises are best. Patients should avoid running and jumping exercises and do more gliding type exercises, such as walking, biking, swimming or using an elliptical trainer. Your doctor or physical therapist can help develop an individualized exercise program that meets your needs and lifestyle.
Acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), and topical creams and sprays can combat pain and inflammation. If over-the-counter medications don't provide relief, your doctor may give you a prescription anti-inflammatory drug or other medication to help ease the pain.
Corticosteroids are powerful anti-inflammatory drugs that can be injected directly into the knee to relive pain and reduce swelling. However, injestcion need to be used in conjuction with weight loss and exercise to optimize the success of non-operative treatment.
Viscosupplementation involves the injection of a gel-like substance called hyaluronate into the knee joint to supplement the properties of synovial fluid and lubricate the area. The injections appear to have pain-relieving properties however it remains unknown scientifically as to why these injections work.
If these non-operative treatments don't work, knee replacement surgery is a good option. It is a safe and effective procedure to relieve pain and help you resume normal activities.
Today, most knee replacement surgeries are minimally invasive, with numerous benefits to the patient. These include smaller incisions, less tissue trauma, bleeding and post-operative pain, shorter hospital stays, faster recovery, and earlier return to work and everyday activities.
Recovery from knee replacement surgery varies by patient. Advancements in minimally invasive approaches, improved implant material and design, and refined surgical techniques have dramatically reduced recovery time. For these patients, the typical recovery period is now weeks rather than months. For patients with isolated arthritis to specific areas of the knee, a partial knee replacement as opposed to a total knee replacement may be an option.