how to protect your joints from diseases

The knee is the largest joint in your body.

It is made up of four main things: bones, ligaments, cartilage and tendons.

Bones
Your knee joint is formed where three bones meet. These are your:

thighbone, which is also known as the femur
shinbone, which is also known as the tibia
kneecap, which is also known as the patella.
Ligaments
These join bones to other bones. There are four main ligaments in your knee. They act like strong ropes to hold your bones together and keep your knee in place.

These ligaments in your knee are:

Collateral ligaments – which are found on the sides of your knee. One is on the inside and one is on the outside. They control the sideways movement of your knee.
Cruciate ligaments – which are found inside your knee joint. They cross each other to form an X shape. These ligaments control how your knee moves backwards and forwards.
Cartilage
There are two types of cartilage in your knee:

Articular cartilage
This covers the ends of your thighbone and shinbone, and the back of the kneecap. This is a slippery substance that helps your knee bones glide smoothly across each other as you bend or straighten your leg.

Meniscal cartilage (meniscus)
These are two wedge-shaped pieces that act as shock absorbers between your shinbone and thighbone.

The medial meniscus is on the inner side of the knee joint.

The lateral meniscus is on the outer side of the knee.

The meniscus helps to cushion and stabilise the joint, which is why they are tough and rubbery. When people say they have torn cartilage in the knee, they are usually talking about torn meniscus.