How do bone cells get nutrients and oxygen through the blood vessels?

Bone is vascularized. Since bone tissue is hard it requires canals or tunnels to get the nutrients to the cells inside it (osteocytes) These cells have long protrusions of their cytoplasm within these tunnels that touch other osteocytes, they are joined at the same unions and can transport nutrients etc to eachother.
Because bone tissue is hard, certain cells act as canals for the nutrients. These cells have long protrusions that touch the other cells within to send the nutrients from the outer of the bone inward.