*3.2.1 Cancellous autograft*

This is the most common procedure among autografts and has shown success for various purposes majorly nonunions. It starts with hematoma formation resulting in recruitment of mesenchymal stem cells (MSCs), while simultaneously, necrotic graft is eliminated by macrophages [16, 17]. Neovascularization also takes place along with this, and finally, osteoid produced by osteoblasts lining the dead trabeculae forms new bone through mineralization, which takes a period ranging from 6 to 12 months post-operation [18]. The most common donor site is the iliac crest due to large surface of trabecular architecture and availability of growth factors [19, 20]. Recent report showed superior osseous bridging after bilateral tibial tuberosity advancement (TTA) over no graft in dogs [21]. Earlier, bone union was observed in graft harvested from scaphoid nonunion distal radius or iliac crest and headless compression screw to treat scaphoid nonunion [22]. Although being the gold standard, the limitation of the amount and donor site morbidity hinders its use.


**Table 1.** 

*Common advantages and disadvantages associated with an autograft.* 

*Application of Bone Substitutes and Its Future Prospective in Regenerative Medicine DOI: http://dx.doi.org/10.5772/intechopen.85092* 

#### *3.2.2 Cortical autograft*

It shows creeping substitution, that is, deposition of new bone along with slow resorption of the graft. The process provides distinguished structural support. This graft also faces limited supply of osteoblasts and revascularization is impeded too.

#### *3.2.3 Vascularised autograft*

This type of graft promotes fracture healing and minimizes loss of bone strength after post-implantation. However, this graft also faces technical challenges for the preservation of graft's osteocytes and osteoprogenitor cells.
