There are many factors that can affect allograft materials. The bone is harvested from the donor after death. The ability to cause bone growth is affected by the donor's age and bone quality. The way the bone is harvested and processed is also important.

Studies show that allograft materials work much better when combined with autograft bone. Autograft material refers to bone donated by the patient for his or her own use. The pelvic bone is the site used most often for autografts.

Allografts seem to function best as a bone graft extender. This means the framework for bone growth is already in place. Bone inducing cells (autograft material) are already present. The allograft helps bone to extend beyond the original bone.

Allograft has a significantly lower fusion rate when used as stand-alone graft material. It is recommended that allograft should only be used as a graft extender unless there is no other autograft bone available.