Related Experiment Video
Updated: Jul 19, 2026

Establishment and Evaluation of a Sheep Model of Full-thickness Osteochondral Defect
Published on: April 14, 2026
Articular cartilage collagen: an irreplaceable framework?
1University of Washington, Dept. of Orthopaedics and Sports Medicine, Box 356500, Seattle, WA 98195-6500, USA. deyre@u.washington.edu
Abstract:
Adult articular cartilage by dry weight is two-thirds collagen. The collagen has a unique molecular phenotype. The nascent type II collagen fibril is a heteropolymer, with collagen IX molecules covalently linked to the surface and collagen XI forming the filamentous template of the fibril as a whole. The functions of collagens IX and XI in the heteropolymer are far from clear but, evidently, they are critically important since mutations in COLIX and COLXI genes can result in chondrodysplasia syndromes. Here we review what is known of the collagen assembly and present new evidence that collagen type III becomes covalently added to the polymeric fabric of adult human articular cartilage, perhaps as part of a matrix repair or remodelling process.
Related Concept Videos
Collagens are the Major Structural Proteins of ECM
Connective tissue proper includes loose...
Growth of Cartilage and Bone Tissue
Structural Joints: Cartilaginous Joints
There are two types of cartilaginous joints:
Synchondrosis
A synchondrosis ("joined by cartilage") is a cartilaginous joint where bones are connected by hyaline cartilage. Synchondrosis may be temporary or...
Structural Joints: Synovial Joints
The Bone Matrix
Bone as Supporting Connective Tissue
Bone Matrix
Bone, or osseous tissue, is a connective tissue that has a large amount of two different types of matrix material. The organic matrix is similar to the matrix material found in other connective tissues, including some amount of collagen and elastic fibers. This gives strength and flexibility to the tissue. The inorganic matrix consists of mineral salts— mostly calcium salts— that give the...

