Articular Cartilage - Role in Canine Arthritis

The main functions of articular cartilage are to facilitate the movement of one bone against another and to act as a ‘shock abosorber’. It has a very low friction co-efficient and has properties that make it able to withstand enormous forces. It is a smooth, white with a bluish tinge, glistening tissue and is also commonly known as hyaline cartilage.


The glassy appearance of articular cartilage is due to two factors:

1. the high water content (70% in adults and up to 90% in newborns)

2. the fine structure of its collagen fibril network, which is made up of the following:

* Collagen – 50%
* Proteoglycans – 35%
* Glycoproteins – 10%
* Minerals – 3%
* Lipids – 1%
* Chondrocytes – 1-2%


Most (85-90%) of the collagen in articular cartilage is type II collagen and this provides the tensile stiffness. There are also small amounts of types VI, IX, XI, XII and XIV. Type IX collagen is linked to type II and is important in stabilising the three-dimensional organisation of the matrix.