Non-unions occur mostly due to fracture stability, decrease in blood supply, or both. The cause of non-union is subcategorised into biological and mechanical factors. There are several risk factors for non-union which include -but are not limited to smoking, diabetes mellitus, infection, open or compound fractures, senility, inadequate nutrition and some drugs like NSAIDs. Mechanical factors include the application of electric fields, physical stimulation and ultrasound. The biological materials include osteoconductive agents such as tricalcium phosphate (TCP), hydroxyapatite (HA) preferably with added Osteoinductive agents, which enhance migration, proliferation and differentiation of cells to promote fracture healing. Such agents as Platelets rich plasma (PRP), Bone marrow aspirate concentrate (BMAC), and Bone morphogenetic protein (BMP).
Keywords: Bone defects, Bone Marrow Aspirate Concentrate (BMAC), Delayed union, Expanded stem cells, Fracture, Malunion, MSCs, Non-union.