About Your Knees

The knee is the largest joint in the body and, although it looks simple enough in diagrams, it is one of the most complex in the human body and the most prone to injury as it’s used so much.

Although the knee joint is only made up of four bones, it is more complex than it seems because these are all  are connected by muscles, ligaments (tough bands of fibrous tissue that connect bone and cartilage, a protective layer that covers the end of bones) and tendons (fibrous bands of tissue which join muscles to bones). All of these can be injured and strained. The knee joint not only flexes and bends but also has a slight rotational component and this is partly the reason why it’s so prone to injury.


What can go wrong with your knees?

The causes of knee joint problems fall into two broad categories:


The most common reason for a knee replacement operation is osteoarthritis – this is where cartilage (tissue which covers the bone ends in the joint) becomes damaged and thins causing a stiff joint which is painful to move and come sometimes be inflamed. Symptoms include pain, stiffness, a grinding sensation and soft and hard swellings. In some cases the cartilage breaks away, causing bones to rub against each other.

You’re more prone to it if you’re over 40, a woman, overweight, have had a previous injury, your parents have had it or your joints have been damaged by other diseases including gout, haemophilia (which causes bleeding into the joints) and rheumatoid arthritis. Joints can also be damaged by rheumatoid arthritis, a chronic disabling and progressive auto-immune disease which can affect the whole body causing swelling and damaging cartilage and the bone around the joint.


The knee  is one of the hardest working frequently used  joints in the body, so strains, tears and sometimes fractures can occur either from playing sports including football and rugby and running, or random falls, accidents and awkward movements. Sometimes serious ligaments and tendon injuries can occur from everyday movements.

Click here to find out about types of surgery for knee problems