Bone Graft Harvest
Bone graft harvesting is done to either increase the chance of a successful joint fusion (ex. ankle fusion, hindfoot fusion) or to help fill a void where bone is absent to due a non-union. A non-union is a situation where a fractured bone or previous attempted joint fusion fails to heal normally. In a bone harvest the soft (cancellous) bone is scooped out from one part of the body (donor site) and packed into the area where bone healing is required. Bone that is taken from the patient’s own donor site and transferred to another site on their body is called an autograft. An autograft helps healing in three ways:
- It provides a scaffold for new bone to form on;
- The bone graft provides a stimulus for healing elements (growth factors, etc) to migrate to the healing area; and
- Bone cells (osteocytes) found in the bone graft may produce new bone directly
Common sites for harvesting bone autograft in foot and ankle surgery include: the proximal tibial, the iliac crest, and the heel bone (calcaneus). There is some suggestion that the closer to the center of the body, the better the quality of the bone graft (i.e. iliac crest may be better than proximal tibial bone graft which may be better than a calcaneal bone graft). However, areas closer to the center of the body can also cause increased pain and discomfort. The ideal site for harvesting bone graft balances the quality and quantity of bone that can be obtained with the expected pain and morbidity at the donor site.
An alternate to autograft is using bone from a cadaver which is called an allograft. The allograft bone is tested for diseases and does not cause an immune reaction in the patient. In addition, it does not cause donor site morbidity.
Whereas autograft provides all three benefits listed above, most allograft lack one or more of these benefits. As a result, surgeons sometimes combine stem cells and/or growth factors with the allograft to stimulate bone healing similar to autograft.
Bone graft is an important part of many foot and ankle operations. Whether bone graft is needed, and the type of bone graft used, may differ depending on the requirements of the surgery. A thorough discussion with the surgeon will be important in understanding how bone grafting might be used in a patients surgery.
Edited February 4th 2024
Previously edited by David Oji, MD