Table 2.
Zones of fibrocartilaginous entheses.
| Composition | Significance | |
|---|---|---|
| Zone 1 | Fibroblasts | Linearly arranged collagen with mechanical properties similar to mid-substance tendon (1,8,10,11) |
| Pure Dense Fibrous | Type I Collagen | |
| Connective Tissue | Type III Collagen (1,8,10,11) | |
|
| ||
| Zone 2 | Fibrochondrocytes | Dissipates bending of collagen fibers in tendon (2) |
| Uncalcified Fibrocartilage | Proteoglycan aggrecan with Collagen (Types I–III) (1,2,8,10–14) | |
|
| ||
| Tidemark | Basophilic demarcation between uncalcified and calcified fibrocartilage representing the boundary between soft and hard tissues (8) | |
|
| ||
| Zone 3 | Fibrochondrocytes | Irregularity of attachments into bone give mechanical integrity of enthesis (2) |
| Calcified Fibrocartilage | Type II Collagen (Predominant) | |
| Type I Collagen | ||
| Type X Collagen (1,2,3,10–14) | ||
|
| ||
| Zone 4 | Osteocytes | Provides sites of attachment for the tendon |
| Bone | Osteoblasts | |
| Osteoclasts (1,8) | ||
| Type I Collagen | ||