Broadly speaking, there are two types of arthritis:
- Osteoarthritis – due to mechanical damage
- Inflammatory arthritis, for example, rheumatoid arthritis, psoriatic arthritis.
This is thought to be caused by the process of “wear and tear” of the articular cartilage. It may be predisposed by:
- Fracture of a bone going through the joint
- Articular cartilage damage from any injury
- Abnormal alignment of the leg, for example bow legs, knock knees
- Injury which has led to damage of knee ligament or the meniscus
- Certain sporting activities, for example, prolonged running
- Family history
Damage to the articular cartilage is progressive. Eventually it may become completely worn away in patches exposing bare bones, which then may rub against each other causing pain. Debris of cartilage floating in the joint may also cause irritation and inflammation in the joint lining and this is a second source of pain. One may feel the joint to be ‘grinding’.
X-rays show narrowing of the ‘joint space’ along with other features of arthritis. There is no blood test for osteoarthritis.
RHEUMATOID ARTHRITIS (RA)
This is a systemic disorder, which means that it affects various organs of the body apart from the joints.
The inflammation starts in the lining of the joint (synovium) and eventually destroys the joint cartilage. In this condition the bones become soft. Rheumatoid arthritis affects many joints simultaneously, including the small joints of the hands. There are other variants of rheumatoid arthritis but these are essentially similar in nature.
X-ray changes in RA are similar to osteoarthritis in terms of joint space narrowing but the pattern may be different. There is usually a loss of bone density.
Blood tests for rheumatoid arthritis are not very accurate.
People afflicted by advanced knee arthritis have significant symptoms which may include:
- Constant pain, even at night with disturbance of sleep
- Stiffness of the joint, more pronounced after rest
- Flexion and extension of the joint is often limited
- There may be occasional or constant swelling of the knee
- Medication may relieve some of the pain but does not take it away completely
Partial or Total Knee Replacement depending on the extent of the damage