KNEE ARTHRITIS
Arthritis is a general term used where a joint surface or cartilage wears out. The joint surface is normally covered by a smooth articular surface that allows pain free movement in the joint. This surface can wear out for a number of reasons; often the definite cause is not known.
When the articular cartilage wears out the joint becomes mildly inflamed and subsequently deformed, both causing pain. This condition is referred to as Osteoarthritis or “wear and tear” and often occurs with aging. It is the most common type of arthritis.
- Causes of Arthritis
- Symptoms, signs and investigations
There are numerous conditions that can predispose to osteoarthritis arthritis but often the exact cause is never known. In general, but not always, it affects people as they get older. Predisposing factors include:
- Trauma to the joint itself. This may be from fracture or ligament tear (eg ACL tear).
- Severe malalignment of the limb (from developmental disease or previous fracture elsewhere in the limb)
- Systemic inflammatory disorders like Rheumatoid Arthritis
- Increased stress from obesity
- Infection in the joint
Knee Arthritis causes pain, swelling, stiffness, and in the later stages a deformity of the knee joint may become apparent. Typically there is pain when weight bearing, sometimes even when walking on flat ground. Later in the process there may be night pain after any activity. The diagnosis is usually confirmed by examination, especially in the advanced cases.
In the arthritic knee the cartilage loss is often best revealed on simple X-rays, which can be taken whilst in the standing position. In earlier stages of the condition, MRI may detect milder damage to the cartilage surfaces, although this is only available in the lying position.
