Endocytes

Endost cells are flat cells and cover 80-95% of the surface of the bone. A descent from inactive osteoblasts is assumed.

They form a protective layer and a functional monitoring unit together with the canal system of the osteocytes. Endost cells also participate in the bone remodeling cycle. They remove fragments of bone collagen (remnants of osteoclasts activity), thus cleaning the bone surface of resorption remnants and initiating subsequent bone formation.

https://en.wikipedia.org/wiki/Endocyte