What is knee arthritis?
Arthritis is characterized by damage to the surfaces of the joint where they make contact with one another. In the knee, arthritis impacts the ends of the femur (thigh bone) and tibia (shin bone) and the patella (kneecap). In healthy knees, the surfaces of the knee joint are surrounded by a protective covering of cartilage. When cartilage breaks down due to injury, aging, normal wear and tear, or other conditions, the bones can begin to rub directly together. The normal joint space between the bones narrows, and bone spurs (osteophytes) and cysts can form. Invariably, the menisci are also damaged and become torn as a part of the arthritic process, and when the damage to the joint becomes severe the ligaments around the knee can be affected too.
Knee arthritis causes joint pain, stiffness, and immobility. With very severe arthritis, the leg may develop bowing ( also known as a “varus” deformity) or become “knock kneed” (also known as a “valgus” deformity), and patients may feel the knee is unstable once the ligaments are damaged.
There are several different types of knee arthritis that can all lead to destruction and deformity of the knee joint.
What are the different types of knee arthritis?
Though the symptoms associated with arthritis in the knee may be similar regardless of the type of arthritis, the reasons for developing the disease can range. In general, arthritis can be divided into primary arthritis and secondary arthritis. Primary arthritis includes osteoarthritis and inflammatory arthritides, such as rheumatoid arthritis. Secondary arthritis results from other disorders of the knee, such as prior trauma.
Osteoarthritis of the Knee
Osteoarthritis (OA) of the knee is a common condition, characterized by degeneration of the cartilage in one or both knee joints due to wear and tear over time. Osteoarthritis usually develops slowly, resulting in eventual bone-on-bone friction, knee pain, stiffness and bone spurs in some cases. Osteoarthritis may be limited to only one “compartment” of the knee. Most commonly, the medial compartment is affected in isolation. When only one compartment is severely arthritic, a partial knee replacement is a consideration for treatment. When two or more compartments are severely arthritic, a total knee replacement is usually the best treatment option.
Inflammatory Arthritis of the Knee
Inflammatory arthritis is a group of autoimmune diseases. These forms of arthritis occur as a result of one’s own immune cells attacking the joint. These diseases may affect multiple or all joints in the body. Types of inflammatory arthritis include:
- Rheumatoid arthritis
- Psoriatic arthritis
- Ankylosing spondylitis
- Juvenile idiopathic arthritis
- Systemic lupus erythematosus
In some patients with these conditions, they develop osteonecrosis of the knee and eventual secondary arthritis as a side effect of disease treatment with chronic and/or high-dose steroids.
Learn more about inflammatory arthritis from hss.edu or arthritis.org
Secondary Arthritis of the Knee
Secondary arthritis of the knee is a form of arthritis that’s caused by another disease or health condition. Secondary arthritis in the knee may result from:
- Post-traumatic knee arthritis (following a knee injury)
- Skeletal dysplasia
- Knee infection
What causes knee arthritis?
The following conditions can contribute to the onset of knee arthritis:
- Normal aging
- Overuse due to active lifestyle
- Past injury involving the knee joint, such as a meniscus tear, ligament tear, or bone fracture
- Improper joint formation (for example, skeletal dysplasia)
- Malalignment of the leg
- Genetic defects affecting bone or cartilage
- Excess weight
- Other illnesses, causing secondary arthritis
- Metabolic disorders
- Prior knee joint infection
What are the signs and symptoms of knee arthritis?
Arthritis of the knee can manifest in different ways, depending on the individual. If you’re experiencing any of the following symptoms, a consultation with an orthopedic knee specialist is recommended:
- Stiffness in the knee, particularly in the morning or after sitting for long periods
- Pain that increases with activity or prolonged standing
- Pain in the knee going up or down stairs
- Pain in front of the knee with kneeling
- Inability to move the knee joint with full range of motion
- Difficulty doing common tasks, such as standing up or bending down
- Pain, soreness, or inflammation/swelling in the knee
- The feeling of bone rubbing against bone (sometimes accompanied by a “crunching” sound or feeling)
- Warmth in the knee that does not go away
- Pain in the knee that wakes you up at night
How is knee arthritis diagnosed?
Dr. McLawhorn will start by asking you a series of questions to better understand your current bone and joint health and your history pertaining to your knee. In addition to a medical history, a thorough physical evaluation will be performed, during which he will assess your walking, range of motion, and strength around the knee. X-rays are important part of your evaluation to look at the status of your knee joint. X-rays of other relevant areas, such as the pelvis, may be ordered if necessary for an accurate diagnosis. MRI is useful when there is further question about the health of the bone, cartilage, menisci, or muscles around the knee. CT is ordered selectively for patients requiring certain types of knee surgery. Blood work or injections into the knee may be necessary for diagnosis in some circumstances.
How is knee arthritis treated?
Knee arthritis is a progressive condition and the earlier that it is diagnosed and treated, the more likely it is that you can lessen its impact on your life. In some cases, knee arthritis pain can be well controlled with nonsurgical treatments. Dr. McLawhorn is committed to personalized care for all of his patients, using evidence-based methods and nonsurgical treatment options whenever possible. Nonsurgical treatments for knee arthritis may include:
- Avoiding high impact activities
- Losing weight
- Physical therapy
- Anti-inflammatory medications
- Joint injections
- Using devices to assist in walking, such as a cane
- Knee bracing
When knee arthritis is severe or is not responding well to nonsurgical measures, a surgical procedure may be necessary. Procedures recommended to relieve knee arthritis may include:
- Knee arthroscopy is a type of less invasive knee surgery that may be used to treat a torn meniscus in cases where osteoarthritis is occurring in conjunction with a symptomatic, degenerative meniscal tear that causes significant mechanical symptoms, such as painful clicking, catching, or popping in the knee.
- Knee osteotomy is a type of surgery for very young patients with pain and limited arthritis in either the medial or lateral compartment of the knee. In this surgery, the femur (thigh bone) or tibia (shin bone) are surgically broken and the joint surface reoriented to improve alignment of the leg so that the body’s weight is distributed across normal cartilage in the knee. Dr. McLawhorn does not perform this surgery. However, in the rare circumstance that it is required, he will refer patients to a trusted colleague to perform the procedure.
- Partial knee replacement is a surgical procedure involving the removal of the damaged bone and cartilage in one section of the knee joint and positioning new artificial components to restore knee function. Examples are medial and lateral unicondylar knee replacement and patellofemoral joint replacement.
- Total knee replacement is a surgical procedure involving complete replacement of all three compartments of the knee joint with an artificial joint.
If you believe you may be suffering from knee arthritis, it is important to seek advice from an orthopedic knee specialist to accurately diagnose and treat your condition. Dr. McLawhorn is a hip and knee specialist at Hospital for Special Surgery serving patients in New York City, and Stamford, Connecticut, with extensive training in diagnosing and treating knee arthritis. To learn more, call 203-705-2113 (CT) / 212-606-1065 (NYC) today or schedule an appointment by using the form on this page.