What Is Bone Graft

Bone grafting is a commonly performed surgical procedure. A bone graft transplants bone tissue. Bone grafts to repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some types of fractures or cancers. Once your body accepts the bone graft, it provides a framework for growth of new, living bone.

Bone has the ability to regenerate completely if provided the space into which to grow. As native bone grows, it  replaces  the graft material completely and results in a fully integrated region of new bone.

Depending upon the source where the graft is taken from, the bone grafts can be autograft or allograft.

Autograft

Also called autologous or autogenous bone graft, this kind of graft is obtained from the same individual receiving the graft. Bone can be harvested from non-essential bones, such as the iliac crest. Iliac crest is most common source of autografts in orthopedic surgery. Other places where graft can be taken from is fibula or metaphyses of long bones.

However very small quantity can be taken from long ends of the bones.

Autogenous bone is the most preferred for the grafting and is deemed as gold standard. There are no risks of graft rejection as the graft originated from the patient’s own body. It is most efficient graft type.

However autografts are associated with an additional surgical procedure and  potential for post-operative pain and complications.

Normally a bone graft is either used in blocks or slivers after being harvested. Sometimes grafts are also harvested especially with their suppying vessel and the blood vessel is reanastomesd to the blood vessel at recipient site.

Such a graft is called vascularized graft.

Vascularized fibulae grats  have been used to restore skeletal integrity to long bones of limbs in which congenital bone defects exist and to replace segments of bone after trauma or malignant tumor invasion. The periosteum and nutrient artery are generally removed with the piece of bone so that the graft will remain alive and grow when transplanted into the new host site. Once the transplanted bone is secured into its new location it generally restores blood supply to the bone in which it has been attached.

Allografts

Allograft bone, like autogenous bone, is derived from humans; the difference is that allograft is harvested from an individual other than the one receiving the graft. Allograft bone is taken from cadavers that have donated their bone so that it can be used for living people who are in need of it; it is typically sourced from a bone bank.

There are three types of bone allograft available.

1. Fresh or fresh-frozen bone
2. Freeze-dried bone allograft
3. Demineralized freeze-dried bone allograft

Xenografts

Xenografts are grafts taken fro species other than humans. Till now xenografts have only historical and experimental significance.

Bone Substitutes

Bone substitutes are synthetic materials that are aimed to replace bone grafts. Partial success has been achieved with these and these are discussed separately.