Osteoarthritis is the most common type of arthritis. It is often referred to as ‘wear and tear’ arthritis and occurs when the protective articular cartilage that cushions the ends of the bones wears down over time, although it is actually more complicated than this.
Whilst the risk of osteoarthritis increases as we get older, it is not inevitable.
The knee is one of the joints that is most commonly affected by osteoarthritis. There can be a strong genetic component to osteoarthritis, with arthritis running in families. It can also develop if you have had previous knee injuries such as fractures, meniscal tears, articular cartilage injury or ligaments injuries. Being overweight also puts extra load on weight-bearing joints and can increase the risk of severe osteoarthritis.
Rheumatoid arthritis is an entirely different inflammatory auto-immune disease but can also result in secondary damage to the joint.
The usual symptoms of osteoarthritis include pain, swelling and stiffness which is often aggravated by activities. Mechanical symptoms of catching, locking or giving way are common, especially if there are any loose or torn pieces of cartilage. You may also experience crepitus or a grating noise from the joint. Most people with osteoarthritis find they have good days and bad days.
The diagnosis of osteoarthritis does not need any special tests. Usually, the history and examination are supported by X-rays which confirm the diagnosis. Sometimes a MRI is useful.