A non-union is a broken bone that fails to heal. These result from both civilian and military injuries and lead to pain, suffering and loss of dignity. Recent study (Geris et al 2010) suggested that mechanical, chemical and biological factors should all be present at the right time and right place in order for fractures to unite successfully. However, the exact mechanisms which disrupt this process, resulting in non-union, are still largely unknown, especially at the micro and tissue levels. Therefore, understanding the regulatory factors and mechanisms that result in ossification and remodelling of the haematoma/callus at different length-scales following a fracture could help to unlock new strategies to treat non-union. It is well known that mechanical stimuli alter the local stress/strain conditions at the fracture site and affect both angiogenesis and osteogenesis. Yet, the underpinning mechanisms which regulate tissue angiogenesis and the subsequent mineralisation process and how these processes interact to promote, or inhibit tissue ossification are still not known.