Dr. Michael Kaiser Lead Author of New Bone Graft Recommendations

Sep. 10, 2014

Kaiser_PortraitHow can you tell if you have a reputation for hard work, honesty, and integrity? For Dr. Michael Kaiser, Associate Director of the Spine Center, one clear sign is that he was sought by his colleagues to chair a huge project, the aim of which is to help all physicians of the lumbar spine.

And how can you tell if you love your work? For Dr. Kaiser, it’s the extreme dedication and true enjoyment with which he conducted the massive project. The project was the seventeen-chapter guideline update on lumbar fusion published last month in Journal of Neurosurgery: Spine.

Dr. Kaiser not only coordinated the entire project and served as its senior author, but he was also the lead author on three of the chapters, including an extensive chapter focusing on bone graft supplements.

When performing a lumbar fusion, grafting of bone is necessary to provide long-term stability to the spine. The gold standard has traditionally been to harvest bone from the patient’s own iliac crest, or pelvis. The patient’s own bone contains the essential elements for successful fusion, provides a scaffold for bone growth, and encourages new bone formation.

Unfortunately, harvesting bone from the patient’s pelvis presents several challenges: there is a limited supply of bone, and the surgical time and blood loss are increased. More importantly, significant pain can develop at the harvest site, impairing the patient’s ambulation and prolonging the recovery time. To avoid these issues, emphasis has been placed on the development of supplements or substitutes for iliac crest bone. Options include donor bone, bone harvested from the spine, and synthetic calcium salt compounds. Unfortunately these alternatives do not have the same potential for bone growth as iliac crest bone.

No alternative, however, has gained more attention than the Bone Morphogenic Proteins, or BMPs. Produced by the human body, these proteins promote and orchestrate new bone growth. Through recombinant DNA technology, these proteins can now be synthetically produced and are readily available. There is no question that these powerful substances can produce the desired bone growth for successful spinal fusion surgery. They have therefore become extremely popular: their use has more than tripled between 2003 and 2007.

However, evidence suggests that the widespread use of BMPs may have been premature, occurring prior to a thorough review of all the data. Right now, the use of BMPs in lumbar fusion surgery is mostly considered off-label, or not specifically cleared for that application by the FDA. In addition, the routine use of BMPs may not be cost-effective, and BMPs have been associated with potentially serious side effects. The controversy surrounding the use of BMPs has exploded in recent years.

As a testament to Dr. Kaiser’s reputation, integrity, and impartiality, he was chosen as the lead author for this controversial topic. Dr. Kaiser and his team of experts took a close look at the medical evidence on BMPs. They found that many studies investigating the use of BMPs suffered from significant flaws that make it difficult to form valid conclusions. The review in Journal of Neurosurgery: Spine concludes that “it is likely that certain patient populations would benefit from the addition of BMPs when performing spinal fusion surgery, but that current studies haven’t fully identified which patients will benefit most.”

The guideline provides direction for future study, involving a coordinated multidisciplinary effort from experts in various fields who are invested in the care of patients with spinal disorders.

Learn more about Dr. Michael Kaiser on his bio page here.

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