Cartilage 101 – What Is Cartilage and What Does It Do?

Dr. Bryan M. Saltzman, MD

We often hear about the importance of cartilage to protect our joint health. But what exactly is cartilage, and how does it keep our joints healthy?

Dr. Bryan Saltzman, MD, breaks down the basics is part one of Cartilage 101. Dr. Saltzman specializes in cartilage restoration, adolescent and adults sports medicine, shoulder & elbow and knee.

What is cartilage?

Cartilage is the main type of connective tissue seen throughout the body. It serves a variety of structural and functional purposes and exists in different types throughout our joints, bones, spine, lungs, ears and nose.

What is cartilage made of?

Cartilage a strong and smooth substance made up of “chondrocytes,” or specialized cartilage cells, that produce a matrix of collagen, proteoglycans (a special type of protein) and other non-collagenous proteins. These materials help cartilage attract water and give it its shape and specific properties.

What are the different types of cartilage?

There are three main types of cartilage: elastic cartilage, fibrocartilage and hyaline cartilage. These types vary in their make-up of the substances listed above.

Elastic Cartilage

Elastic cartilage is present in the ear, nose and parts of the lungs. It is a highly flexible formulation of cartilage.

Fibrocartilage

Fibrocartilage is found in the menisci of the knee and the discs of the spine. It is far less flexible than elastic cartilage.

Hyaline Cartilage

Hyaline cartilage is found at the ends of bones – lining the joints of the body – as well as the septum of the nose and part of the breathing tube.

Why do we need JOINT cartilage?

Hyaline, or articular, cartilage covers the ends of bones to create a low-friction environment and cushion at the joint surface. When cartilage in the joint is healthy, it effectively allows fluid bending/straightening motions and protects the joint against weight-bearing stresses.

What happens when joint cartilage is damaged or unhealthy?

If the cartilage begins to degenerate with age, or if it were to become damaged from an injury, the joint loses some of that protective cushion and exposes underlying bone ends. This damage can lead to excess stress of those areas of bone that are ill-equipped to handle strong forces.