Osteoarthitis (knee)

What is osteoarthritis?

Osteoarthritis (OA) is a chronic joint disease characterized by degeneration of joint cartilage and adjacent bone. OA may affect any joint containing hyaline cartilage, such as the peripheral joints of the knee, hip cervical and lumbar spine. OA in the lower extremity joints is particularly common. When joint cartilage is damaged, the sensitive bone tissue that is usually protected by the cartilage, becomes stressed causing degenerative changes in the joint. Sometimes the bone around the joint will proliferate and make osteophytes or what are more commonly called bone spurs. These spurs can cause painful irritation to other tissues around the joint thus complicating the already hurtful condition.

OA is classified as primary or secondary. Primary OA is not fully understood, but factors such as sex and aging is contributed to it. In the knee, local factors such as previous knee trauma, fracture and obesity contribute to the degeneration of cartilage, and consequently OA.

The osteoarthritic process is a slow progression of degenerative changes. In the knee, cartilage loss may occur in the medial, lateral and/or patellofemoral compartment. OA may be unicompartmental, occurring in one compartment only, or bicompartmental or tricompartmental OA, with disease pathology occurring in all three compartments of the knee.

Diagnosis of OA

The diagnosis is made by a history of these symptoms and confirmed by physical exam and plain x-rays. Physiotherapist performs a physical examination to assess a person's biomechanical alignment, which helps determine which compartment of the knee is effected. For example, a person that has genu varum alignment, or is commonly referred to as being bow-legged, suggests medial compartment involvement. Genu valgum alignment predisposes a person to lateral compartment osteoarthritis. In the early stages of OA, pathology is not always synchronous with clinical evidence of OA. As the osteoarthritic process progresses, the surface of the knee joint becomes swollen, resulting in sufferers displaying clinical signs of inflammation. Other signs such as crepitus (cracking or grinding) and tenderness at the joint line become more prominent as bony changes occur and cartilage degeneration continues.

As the cartilage loses its elasticity, range of motion in the knee is lost, and sufferers of OA complain of stiffness in the knee. Patients describe knee pain that is diffuse, or specific to the compartment of the knee affected. The pain is typically activity related, made worse with weight bearing and improved with rest. The loss in motion, and chronic pain, makes daily living tasks such as walking and climbing stairs, extremely difficult for people living with OA. For these reasons, osteoarthritis of the knee accounts for more dependency in daily living tasks.

Clinical features

• joint space narrowing
• the presence of osteophytes (bon spur)
• morning stiffness
• pain with activity
• swelling
• muscle weakness
• crack sound heard during movement
• dull toothache like pain, especially with weather changes
• In the later stages, progressive disability and pain increase arise.
• decreased motion in the knee

Treatments

1. Reduce inflammation and pain
   • Ice therapy
   • Ultrasound
   • Interferential treatment
2. Joint mobilization to increase range of motion and reduce stiffness
3. Exercise therapies
   1. Strengthening exercises
   • strengthen the muscles around the knee joints
   • to protect from injury
   • increase muscle endurance
   2. Stretching exercises
      • Improve muscle and joint flexibility
4. Acupuncture
5. Functional treatment
6. Daily activities modification
7. Hydrotherapy
   • make use of water resistant to train and strengthen muscle around knee joint
   • make use of water buoyancy to decrease the impact of knee joint during exercises.

Exercises suitable for OA knee

1. Prevent vigorous exercises such as
• High impact exercise
• High loading to knee joint
2. Tai Chi
3. Walking
4. Swimming

Prevention

• Weight control
• Not to carry heavy objects
• Wear shock absorbing shoes
• Prevent prolonged squatting, walking and kneeling tasks
• Don’t sit on low chair