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Why is articular cartilage both deformable and elastic?

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Medical illustration of a human knee joint in a parasagittal section just lateral to the midline, labeling ligaments, cartilage, meniscus, patella, synovial structures, and surrounding muscles and fat pads. — joint The ligaments and cartilage in a knee joint.

Articular cartilage is a type of hyaline cartilage that covers the ends of bones in free-moving joints. Its unique ability to be both deformable and elastic is essential for its function, as it allows the tissue to absorb compressive shock and recover its shape quickly once the stress is removed.12

The physical properties of this tissue are primarily due to its specialized extracellular matrix. This matrix is a gel-like substance containing collagen fibrils and highly organized proteoglycans. These proteoglycans are large, acidic molecules that bind an extraordinarily large amount of water, which provides the cartilage with its characteristic firmness and resiliency.13

Because of this composition, the cartilage can undergo mutual deformation to improve the fit between articulating bone surfaces, while its elasticity ensures it returns to its original form, protecting the joint from the impact of movement.2