The knee is a hinge joint made up of three different compartments:- The patello-femoral compartment (kneecap), the medial compartment (inner chamber of the knee) and the lateral compartment (outer chamber of the knee).

Within the knee are several important structures including:

Ligaments – These provide support to the knee, when it moves. It includes the cruciate ligaments as well as the medial and lateral collateral ligament.

Cartilage – The knee is coated in a smooth bearing surface (articular cartilage) to allow it to glide easily.

Meniscus – Consisting of the medial (inner) and lateral (outer) meniscus these structures help the knee bend and rotate, as well as acting as shock absorbers.

In knee arthritis the bearing surfaces (articular cartilage) between the parts of the joint wears out. This results in friction within the joint, with a loss of the normal gliding action. This can cause stiffness in the joint, knee pain and difficulty walking. When the arthritis becomes severe the ends of the bone rub against each other and can cause a ‘grating’ sensation. As the joint becomes stiffer it can result in pain in other joints.

Simple pain killers can be used to help control your symptoms and allow you to undertake everyday activities. In the early stages of arthritis it is important to keep the knee moving and maintain the strength in the surrounding muscles. A physiotherapist can help direct you to the most appropriate exercises.

Sometimes symptoms can be further improved by modifying the type of activities you do. For example trying cycling and swimming can reduce the forces going through your joint compared to walking and running.

When the pain becomes more severe, affects your quality of life or wakes you at night then this is when knee replacement surgery may be indicated.