Perichondriet

Perichondriet, more commonly known in English as the perichondrium, is a dense layer of connective tissue that envelops most cartilage, including hyaline and elastic cartilage. It is absent from the articular surfaces of synovial joints and from fibrocartilage. The perichondrium serves as a protective envelope and a source of nutritional support for the cartilage it surrounds.

The perichondrium consists of two distinct layers. The outer fibrous layer is rich in collagen fibers and provides mechanical protection and structural support. The inner chondrogenic (or cellular) layer contains progenitor cells capable of differentiating into chondroblasts and, subsequently, chondrocytes. This cellular compartment is the source of new cartilage cells during growth and repair. The outer layer is typically more vascularized than the cartilage itself, allowing nutrients to diffuse through to the avascular cartilage tissue.

Functionally, the perichondrium supplies nutrients to cartilage via diffusion from its vascular network, facilitates growth by appositional means (adding new cartilage to the surface), and participates in repair by providing chondroprogenitor cells. It also plays a role in the response to injury and in the apposition of cells during development and skeletal remodeling.

Clinical relevance includes its involvement in cartilage repair strategies, where perichondrial or periosteal tissue can contribute progenitor cells for regeneration. Damage or degeneration of the perichondrium can impair cartilage growth and repair, underscoring its importance in musculoskeletal biology.