Areas of new woven bone and cartilage were then traced.
This was accompanied by bone loss and evidence of new woven bone formation.
The strong resorption in treated defects was accompanied by the synthesis of new woven bone and angiogenesis.
The synthesis of new woven bone demonstrates that the implant has induced remodeling and not exclusively osteoclastic resorption.
Histopathology was characterized by new but also partly healed trabecular microfractures, bone demineralization, cysts, metallosis, and abnormal formation of new woven bone.
The increase in the size of new woven bone and callus formation was greater on the concave side than on the convex side at day 7.
Although both subchondral bone resorption and the synthesis of new woven bone were observed, the resorption was definitively stronger during the first three weeks of repair, as evidenced by the larger size of the treated holes compared to acute defects.
In control defects, no signs of bone resorption were present and the subchondral bone contained large blood vessels, low levels of new woven bone, as chondrocytes fused to bone which indicates that endochondral ossification is underway.
Thus, there were equal amounts of new woven bone and callus formation at day 7, complete thickened cortical bridging at day 21, and reduction in cortical size with normal bone architecture at day 35.
Histomorphometric evaluation was performed using the stereological software newCAST (version 3.4.1.0; Visiopharm, Hoersholm, Denmark) in combination with a light microscope (Olympus BX51), and we performed quantitative analysis of surface and volume fractions of new woven bone, lamellar allograft bone, fibrous tissue, and marrow space.
