Knee Osteoarthritis

**Knee Osteoarthritis (OA)** is a chronic disease caused by the deterioration of the cartilage in the knee joint, which functions to allow smooth joint movement. When the cartilage deteriorates, it causes the bones in the joint to rub against each other, resulting in **pain, swelling, and joint stiffness**. This condition is commonly found in older adults but can also occur in middle-aged or younger people in certain cases.

Who is at Risk?

• Older Adults: OA is common in people aged **50 and over** as bones and joints naturally deteriorate with age.
• Female Gender: Women have a higher risk than men due to **hormonal factors** and changes after menopause.
• Overweight or Obese Individuals: Excess body weight increases the **pressure on the knee joint**, leading to faster joint deterioration.
• History of Knee Injury: Injuries from sports, accidents, or previous knee surgery can contribute to the development of knee OA.
• Prolonged Heavy Knee Use: Work or activities that heavily use the knee, such as heavy lifting, squatting, or frequent climbing of stairs, are significant risk factors.

Causes of Knee Deterioration

• Excessive Use: Continuous or overuse of the knee joint without rest causes cartilage deterioration.
• Increasing Age: As people age, the cartilage and surrounding joint tissues naturally degrade.
• Injury: Injuries to the knee joint or surrounding bones can accelerate knee deterioration.
• Other Arthritic Diseases: Rheumatoid arthritis and Gout may also lead to knee OA.

Signs and Symptoms of Knee Osteoarthritis

• Knee Joint Pain: Pain occurs when walking or standing for long periods. The pain often improves with rest.
• Joint Stiffness: Feeling that the knee joint is stiff or difficult to move, especially after waking up or sitting for a long time.
• Swelling and Inflammation: Knee joint swelling due to the accumulation of fluid in the joint and inflammation.
• Grinding Sound (Crepitus) in the Joint: A "กรอบแกรบ" (grop-graeb) sound may be heard when moving the knee joint.
• Limited Movement: Walking, climbing stairs, or standing up may become difficult due to pain and stiffness.

When to See a Doctor

• When there is **continuous or severe knee pain** that prevents daily activities.
• Knee joint swelling is constant and does not improve with rest.
• Feeling of knee instability or leg weakness.
• Limited knee movement; inability to fully straighten or bend the knee joint.

Treatment

1. Medication:

   • Non-steroidal anti-inflammatory drugs (**NSAIDs**) such as Ibuprofen help reduce inflammation and relieve pain.
   • Paracetamol (Acetaminophen) can be used when the pain is not severe.
   • In some cases, a doctor may inject **corticosteroids** directly into the knee joint to reduce inflammation.

2. Physical Therapy:

   • Physical therapy helps **strengthen the muscles** around the knee joint, which reduces pressure on the joint and relieves pain.
   • Appropriate exercise, such as walking, swimming, or light stretching, can help reduce symptoms and prevent the condition from worsening.

3. Weight Reduction:

   • For those who are overweight, **losing weight** can help reduce the pressure on the knee joint and slow down its deterioration.

4. Surgical Treatment:

   Surgical treatment for knee OA is an option used when other methods, such as medication and physical therapy, do not provide sufficient results. Surgery can be divided into several types, depending on the severity of the symptoms and the condition of the patient's knee joint. The details of each method are as follows:

   • Knee Arthroscopy

     Arthroscopy is a surgical procedure that uses a small camera and specialized instruments to view the knee joint through 2-3 small incisions around the knee. This allows the surgeon to inspect internal damage and repair damaged tissue, such as torn cartilage or damaged ligament tissue.

     When to Perform Knee Arthroscopy:

     • Severe Pain: For patients with continuous knee joint pain where other treatments, such as medication or physical therapy, do not improve symptoms.
     • Damage to Tissue around the Knee Joint: For patients with cartilage fragments or loose bone pieces inside the joint, causing friction and inflammation.
     • Sports Injuries: Such as tears in the cartilage or menisci, where arthroscopy can precisely fix the damage with less pain.

     Advantages of Knee Arthroscopy:

     • Small Incisions: Arthroscopy involves small incisions, leading to faster patient recovery and reduced risk of infection.
     • Short Recovery Time: Patients can return to daily activities sooner compared to open surgery.
     • Reduced Risk of Complications: Due to the small incision size and high precision of the instruments.

     Limitations of Knee Arthroscopy:

     • Arthroscopy is suitable for patients with mild deterioration or minor tissue damage. It cannot fix severely damaged knee OA.

   • Total Knee Replacement (TKR)

     Total Knee Replacement (TKR) is the **final stage of treatment** used for patients with severe knee OA where the cartilage is completely destroyed and bone-on-bone friction occurs, resulting in severe pain and inability to walk or use the knee normally.

     When to Perform Total Knee Replacement:

     • Severe OA: When the knee cartilage is completely worn out or bones rub together, and the patient cannot walk or perform daily activities normally.
     • Chronic Pain: For patients with long-term knee joint pain that cannot be alleviated by other treatments.
     • Severely Limited Mobility: When injury or deterioration severely restricts knee movement, affecting daily life.

     Advantages of Total Knee Replacement:

     • Pain Relief: This surgery significantly reduces pain, allowing patients to return to walking and daily routines.
     • Improved Mobility: The artificial knee helps restore movement closer to normal, making walking, climbing stairs, and other activities easier.
     • Better Quality of Life: Patients experience a significantly improved quality of life after full recovery, enabling them to live efficiently.

     Limitations and Complications of Total Knee Replacement:

     • Long Recovery Period: Although highly effective, patients require a period of rest and strict physical therapy, which may take several months to return to normal activities.
     • Surgical Complications: Such as infection, blood clots, or issues with the artificial knee not fitting the patient's bone correctly.
     • Lifespan of the Implant: Artificial knees generally last about **15–20 years**, after which replacement surgery may be necessary.

   • Post-Surgical Care

     • Physical Therapy: After surgery, physical therapy is vital for strengthening the knee joint and speeding up recovery. Strictly follow the advice of the doctor and physical therapist.
     • Use of Crutches or Walker: Immediately after surgery, the doctor may recommend using crutches or a walker to aid walking and prevent the knee joint from bearing excessive weight.
     • Avoid Excessive Bending or Squatting: After surgery, avoid excessive knee bending, squatting, or sitting on low chairs to prevent further injury to the knee joint.
     • Weight Management: Maintain a normal body weight to reduce pressure on the new knee joint.

The treatment of knee osteoarthritis requires a variety of methods depending on the severity of the symptoms. With appropriate treatment and adjustment of knee usage behavior, patients can achieve a better quality of life.