Arthritis causes inflammation in joints, leading to pain, swelling, and stiffness. It is especially common in the knee and can make everyday tasks like walking or climbing stairs difficult. Arthritis is a leading cause of disability and lost work time.
The most common types are osteoarthritis and rheumatoid arthritis, though over 100 forms exist. While typically an adult disease, some forms can affect children. Although arthritis has no cure, treatments can manage pain and help maintain an active lifestyle.
Anatomy of the Knee
The knee is the body’s largest joint, formed by the thighbone (femur), shinbone (tibia), and kneecap (patella). These bones are covered with smooth articular cartilage, which cushions and protects them during movement. The menisci, two rubbery cartilage wedges, act as shock absorbers and provide joint stability. The synovial membrane surrounds the joint, releasing fluid to lubricate and reduce friction.
Types of Knee Arthritis
The main types of arthritis affecting the knee are osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis.
Osteoarthritis: The most common form, osteoarthritis, is a degenerative condition often seen in people over 50, though it can affect younger individuals. It occurs when cartilage in the knee joint gradually wears down, becoming rough and frayed. As the protective space between bones decreases, painful bone rubbing and bone spurs can develop. Osteoarthritis progresses slowly, with worsening pain over time.
Rheumatoid Arthritis: Rheumatoid arthritis is a chronic, autoimmune disease that targets multiple joints, including the knees, often symmetrically. It causes swelling in the synovial membrane, leading to pain and stiffness. The immune system attacks healthy tissue, damaging cartilage, ligaments, and bone.
Posttraumatic Arthritis: This type develops after a knee injury, such as a fracture, meniscal tear, or ligament damage. These injuries can destabilize the joint and cause additional wear, leading to arthritis over time.
Symptoms
Arthritis in the knee may cause pain and inflammation, often developing gradually but sometimes suddenly. Common symptoms include:
- Stiffness and swelling, making it hard to bend or straighten the knee.
- Pain and swelling worse in the morning or after resting.
- Flare-ups from vigorous activity.
- Loose cartilage fragments causing the knee to lock, stick, or grind (crepitus).
- Weakness or buckling of the knee.
- Increased pain with weather changes.
Diagnosis of Knee Arthritis
Your doctor will review your symptoms, medical history, and conduct a physical exam. Diagnostic tests, such as X-rays or blood tests, may also be ordered.
Physical Examination
Dr. Avino will check for:
- Swelling, warmth, or redness
- Tenderness around the knee
- Range of motion (assisted and self-directed)
- Joint instability or crepitus (grating sensation)
- Pain when weight-bearing
- Gait issues or surrounding muscle, tendon, and ligament injuries
- Signs of other joint involvement (possible rheumatoid arthritis)
Imaging Tests
- X-rays: Show joint space narrowing, bone changes, or bone spurs.
- Other Tests: MRI or CT scans may assess bone and soft tissue conditions.
Laboratory Tests
Blood tests may help identify the type of arthritis, particularly rheumatoid arthritis, aiding in accurate diagnosis.
Treatment of Knee Arthritis
While there is no cure for arthritis, various treatments can help alleviate pain and improve function.
Nonsurgical Treatments
Initial treatments focus on managing symptoms through lifestyle changes, physical therapy, and medication:
Lifestyle Modifications: Reduce activities that worsen pain, switch to low-impact exercises, and lose weight to ease joint strain.
Physical Therapy: Tailored exercises can improve mobility, flexibility, and strength.
Assistive Devices: Braces, canes, or knee sleeves may improve stability and function.
Medications:
- Over-the-counter pain relievers like acetaminophen and NSAIDs may reduce pain and inflammation.
- Topical NSAIDs are recommended for localized pain relief.
- Corticosteroid injections may provide temporary relief but should be limited due to potential risks.
- Disease-modifying drugs, like DMARDs or biologics, may slow rheumatoid arthritis progression.
- Supplements like glucosamine lack strong evidence of effectiveness and should be used cautiously.
Alternative Therapies: Options include acupuncture, magnetic pulse therapy, PRP, and stem cell injections, though their efficacy requires further study.
Surgical Treatments
Surgery may be necessary for severe cases unresponsive to other treatments:
Arthroscopy: Rarely used for arthritis unless addressing a meniscal tear.
Cartilage Grafting: Healthy cartilage is used to repair small areas of damage, mainly in younger patients.
Synovectomy: Removes inflamed joint lining in rheumatoid arthritis.
Osteotomy: Reshapes the shinbone or thighbone to shift weight off the damaged joint area.
Knee Replacement: Partial or total knee replacement involves replacing damaged cartilage and bone with prosthetic components to restore joint function.
Recovery after Knee Surgery:
Recovery after knee surgery for arthritis varies depending on the procedure. Physical therapy is often recommended to restore strength and range of motion. You may need a knee brace, crutches, or a cane during this period. Surgery typically reduces pain and improves daily function.
