Helping Fractures Heal (Orthobiologics)
Orthobiologics are substances that orthopaedic surgeons use to help injuries heal more quickly. They are used to improve the healing of broken bones and injured muscles, tendons, and ligaments. These products are made from substances that are naturally found in your body. When they are used in higher concentrations, they may help speed up the healing process.
This article focuses on orthobiologics that orthopaedic surgeons use to help broken bones heal.
When you injure a bone, muscle, or tendon, there is bleeding into the injured area. This bleeding is the foundation for the healing response. It provides a way for healing factors to reach the injury site.
In addition to bleeding, there are three factors necessary for healing. All three are orthobiologic substances. They include:
- Matrix. This can be thought of as the house in which the cells live and where they will thrive and eventually make bone, tendon, or ligament. Matrix material is conductive. This means it can form the building blocks that help fill bone gaps.
- Growth factors. These are the many different kinds of proteins necessary for cells to work during the healing process. Some proteins help speed up the healing process, while others help to control it or slow it down. These elements are much like the vitamins that we take every day to try to improve our health and body function.
- Stem cells. These are special cells in your body that can turn into other types of cells. During the healing process, stem cells are called to the area of your body that needs repair. Factors in the area influence the stem cells to become repair cells. Note that the same stem cell that repairs bone can also repair a tendon or ligament.
Matrix (Conductive Material)
The matrix, or conductive material, provides housing for stem cells while they grow into mature cells. If stem cells do not have a house to grow in, they cannot develop into repair cells that can heal bone, muscle, tendon, or cartilage.
When someone breaks or fractures a bone, the healing process begins. As long as most of the bony substance is not lost, stem cells should be able to make new bone and promote healing. If, however, a significant portion of the broken bone is lost, a large gap may result. This can happen if the bone crumbled, or broke into several pieces and went through the skin.
Under these circumstances, the gap must be filled with matrix, or conductive material, to house stem cells. There are several types of substances that may be used for this purpose.
Bone grafts are often used as matrix material. There are two types of bone grafts.
Autograft. A bone graft can be obtained from the patient. This type of graft is called an autograft. Many different bones can be used to supply the graft. Grafts are most commonly taken from the iliac crest, which is part of the pelvis.
Harvesting a bone graft requires an additional incision during the operation to treat the injury. This makes the surgery take longer and can cause increased pain or risk of infection after the operation. Although autografts have been used with good results, some people may experience pain at the donor site for some time.
Allograft. One alternative to taking the bone graft from the patient is called an allograft, which is cadaver bone. An allograft is typically acquired through a bone bank. Like other organs, bone tissue can be donated upon death.
The use of allografts has grown because it avoids the risk of pain at the donor site. There are risks and benefits for both types of bone grafts, which your surgeon will discuss with you.
Artificial Matrix Material
Man-made materials, such as calcium phosphate, may also be used to fill a large void between bone ends. When treated properly, calcium phosphate can form material that closely resembles bone. It contains holes that are the right size for stem cells to enter and develop into mature cells.
Both calcium phosphate and cadaver bone eliminate the pain and other risks involved with having extra surgery to harvest an autograft.
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