Fig. 1.

Multiscale structures of the tendon-to-bone enthesis. At the macroscale (left), the tendon attaches to the bone with a splayed geometry leading to a large insertion area. The microscale interface (right) is characterized by gradients in cell geometry (open circles, ovals, and diamonds), mineralization (high mineralization is gray and unmineralized is white), collagen orientation (thin lines) and composition. Of interest to this study is the gradient in mineralization between the mineralized and unmineralized fibrocartilage as well as the waviness of this interface.