Answer:
Osteoclasts
Step-by-step explanation:
The osteoclasts are enormous cells, with more than one nucleus, that originate from the bone marrow. Osteoblasts play a significant role in bone remodeling i.e. new bone growth, by helping to break down bone tissues- a process called BONE RESORPTION.
The osteoclasts perform an opposite role to that of osteoblasts (bone-forming cells). They degrade the mineral content of bone tissues and digest the remaining parts intracellularly in their vacuole. Calcium is released into the bloodstream after resorption of bones.
Therefore, according to the question, the fragments of a broken bone will be initially broken down by cells called OSTEOCLASTS before new bone tissue growth can occur.