Bone morphogenetic proteins (BMP) stimulate bone growth naturally in the human body. These proteins that exist in the body can be produced, concentrated and placed in the area of the spine for a spinal fusion to take place. More importantly, they can create a fusion without the need for any use of the patient’s own bone.
Discovery of BMP growth proteins is credited to Marshall Urist, MD, an Orthopedic Surgeon, while he was working in the UCLA Department of Orthopaedic Surgery in Los Angeles, CA.
Types of Bone Morphogenetic Proteins (BMP)
While there are several different BMPs naturally found in the body, research has focused on BMP-2 and BMP-7. BMP-2, the most thoroughly evaluated BMP, in particular has been shown through clinical studies to successfully stimulate spinal fusion equal to or better than the patient’s own bone.
The primary goals of using BMP in spinal fusions are:
- To create a spinal fusion as well as or better than using the patient’s own bone.
- To eliminate the need for harvesting the patient's bone from his or her hip, thus avoiding the potential side effects and complications of the bone harvesting procedure.
Considerations with Bone Morphogenetic Proteins (BMP)
There are a few drawbacks with use of BMP, however, including:
- BMP has only been approved for one type of spinal fusion, anterior lumbar interbody fusion (See FDA approval below).
- BMP is expensive. The recombinant technology to produce the protein, as well as the extensive research and testing necessary for regulatory approval, make it much more expensive (between 200%-500% more expensive) than other bone graft substitutes.
- It is not fully understood how BMP’s work or what other side effects they may produce. They are usually introduced into the body in pharmacological doses (thousands to millions times the amount normally found in the body).
FDA Approval for BMP
BMP-2 has received FDA approval for use in anterior lumbar interbody fusion in titanium cylindrical cages (a form of cages that are not commonly used anymore). Use of BMP in any other type of spine fusion has not been approved and would therefore constitute off-label use of this product.
The FDA recently released a cautionary letter recommending that BMP-2 not be used in anterior cervical fusions as it can cause massive soft tissue swelling with postoperative compromise and restriction of the patient’s airway. There have been multiple reported cases of soft tissue swelling and a few reported deaths. It is not recommended that BMP-2 be used for anterior cervical fusions as there are other effective options.