Osteoarthritis occurs as a consequence of wear and tear on the knee joint over the years. It tends to affect people more as they get older although some lucky people never suffer from any significant joint pains. Others might be unfortunate and develop symptoms of arthritis at a younger age possibly following an injury.

In the knee, the end of the thigh bone (femur), the top of the shin bone (tibia) and the underside of the kneecap (patella) are all covered in smooth joint cartilage. This allows our joints to move freely without excess friction or pain. This knee joint cartilage is protected by the meniscus cartilages which act as shock absorbers. It is the wearing away of this joint cartilage that produces the pain and swelling of osteoarthritis.

The most common symptom is pain. This tends to get gradually worse and start to impact sports, daily activities, and even sleeping.

The knee can feel stiff and look very swollen. This is sometimes from excessive fluid and commonly from the knee growing an extra bone (osteophyte) to cope with the stress placed on it.

The loss of cartilage changes how straight your leg looks when standing – you may see this when looking in a mirror. A bow-legged deformity (varus) is most common, but it can also look knock-kneed (valgus).

Other symptoms can include the knee catching, clicking, locking, or giving way.

Your GP or physiotherapist will usually diagnose your knee osteoarthritisby asking about your symptoms and examining your knee. The diganosis can be confirmed in most cases with simple x-rays of both knees when standing.

MRI or CT scans can be ordered if the x-rays are not conclusive, or if anther knee condition is suspected. Ultrasound scans are rarely useful.