SpineUniverse: Patients are hearing a lot about BMPs. What are they?
Dr. Wang: BMP is the acronymn for Bone Morphogenetic Protein. BMPs are found naturally in the human body, and people need them for all types of normal bone formation. One specific type, BMP-2, is approved for use in the spine. The US Food and Drug Administration (FDA) has approved BMP-2 for use in single-level, anterior lumbar spinal fusions, when placed inside a titanium cage.

There has been a great deal of controversy regarding the use of BMP in spine surgery. This really stems from questions regarding some of the early studies that looked at BMPs use and the reporting of potential complications. Although the FDA approved BMP for use in single-level anterior lumbar fusion procedures using a certain cage, it has been used in other areas of the spine in order to achieve fusion.

Understanding the Potential Risks
Potential complications have led to significant controversy regarding BMPs use. If a patient is having a spinal fusion, it is important they understand the risks of BMP use of as well as the potential benefits. The patient also needs to understand the specific potential risks of BMP use and the potential complications in order to make an informed decision. We are learning more about this evolving topic every month. It is important for the patients to understand this is very controversial.

• Some patients may have an inflammatory reaction and other adverse events when the BMP is used.
• There are studies that have shown a potentially higher rate of the development of some cancers when BMP is used. Although the risk of developing cancer with the use of BMP is low, it is still controversial whether its use contributes to the development of cancer.

SpineUniverse: Are there other biologics currently in use that you believe to be significant breakthroughs?
Dr. Wang: The exciting thing about this area is there are novel biologic materials being studied and new products coming out at a fairly rapid pace. They require careful study for both safety and efficacy.

• One of the more exciting areas is the use of stem cells from a patient's own bone marrow. Bone marrow cells are removed from the patient and concentrated, applied to a biologically active matrix, and used as bone graft replacements. This synthetic, biologically active bone can be used for spinal fusion and can serve as a bone graft replacement.
• Some surgeons are using bone marrow aspirate with their biologic materials without concentrating the cells, with some success.
• Other developments are newer and improved carriers for the cells and matrices that can help extend the amount of graft material that is being used.

SpineUniverse: During the next 5 years, what other new biologic material developments do you envision?
Dr. Wang:
Over the next 5 to 6 years, I see several biologic material advances that will improve the treatment of spinal disorders.

• The first area lies in the newer materials that are currently being refined to replace our older, standard materials used today. These newer materials may help our currently inert cages and metal fixation devices become more biologically favorable with ingrowth surfaces or microstructures to encourage bony ingrowth into the cage or metal surfaces. These developments could result in better biologic materials to promote fusion healing and spinal stability.
• The next area is improved delivery systems for the biologic materials—new carriers or substrates that could promote bone healing. I envision these biologics being delivered by means of more minimally invasive techniques; smaller incisions, less pain, and faster recovery periods.
• The use of sustained- or time-release of the material over a greater and more consistent time period may allow for finer overall healing, with smaller doses of the biologics at a single time point; however, overall, a more effective dose over time. We are hopeful these will result in more improved healing rates.
• The last exciting development lies in extending our therapies into disc regeneration and gene therapy techniques. Gene therapy will allow us to overcome many of the limitations of existing biological restrictions, avoid fusions and preserve motion.
• While we primarily think of biologics in terms of bone healing, biologics hold promise in nerve regeneration or spinal cord injuries. New biological treatments of these devastating problems may have the most impact. Medications or biologics that promote nerve healing is the ultimate goal.

I think this is an exciting time for both patients and spine surgeons.

SpineUniverse: Thank you for your insights Dr. Wang. We appreciate your time.
Dr. Wang: You are most welcome.

Jeffrey C. Wang, MD is one of the leaders in this field. Dr. Wang is based at the University of Southern California (USC) and, in addition to his busy practice, he runs a basic science laboratory where he is constantly developing and testing new methods to treat spinal disorders.