The knee joint is the largest joint in the body. It is made up of 3 main bones – the femur (thigh bone), the tibia (shin bone), and the patella (kneecap). The end of each is covered in smooth articular cartilage. It has some detailed and complex movements but basically it can be viewed as a hinge type of joint.

Aside from the bones, it is held together by two strong cruciate ligaments that are so called because they cross over in the middle of the knee.  There are also ligaments that run down both sides of the joint to help keep it stable, these are called collateral ligaments.  Between the femur and tibia are two complex ‘shock absorbers’ called menisci or cartilages.  Finally the knee is lined with a membrane called synovium (as in the hip) which produces the fluid that acts as a lubricant.

Any of these parts can be damaged by injury or disease and cause problems or symptoms.  These can include clicking, giving way, locking (getting the knee stuck in a bent position) or pain which can range from an ache to a severe pain that keeps you awake at night.

Your doctor can work out what the problem is by careful history and examination, followed by X-Rays or scans.  Surgical treatment ranges from day case arthroscopic knee surgery (key-hole) to joint replacement, but targeted physiotherapy can be effective in simpler cases.