Fig 5. 4-layered tendon-bone interface of ISP enthesis: tendon, nonmineralized fibrocartilage (*), mineralized fibrocartilage (▲) (▲), and bone. (↑) indicates the tidemark.

In the Control and OVX-PTH groups, well-organized ISP enthesis could be observed with a clear tidemark (A, D). Arrangement of nonmineralized fibrocartilage aligned well, nonmineralized and mineralized fibrocartilage were stained deeply and with abundant cells (B, E). In the OVX-PTH group, the nonmineralized and mineralized fibrocartilage were thicker with a more compact structure (E, F). In OVX-Saline group, a relative thinner tendon-bone interface was observed, as well as a less clear tidemark in the enthesis (G). The cell deposition in the area was less compared to the other groups, and osteoclast number and bone lacuna in the mineralized fibrocartilage seemed to have increased compared to both Control and OVX-PTH groups (H, I).