The past two years have seen growing concern over the safety of a device commonly used in spinal fusion surgeries called Infuse or Amplify. This device contains a genetically-engineered substance called bone morphogenetic protein (BMP) that stimulates bone growth, both eliminating the need for a bone graft and increasing the rate of successful vertebral fusion.
As complaints of complications mounted, Professor of Orthopedic Surgery Eugene Carragee and his Stanford colleagues decided to take up an independent investigation, reviewing 15 years of research and data publicly available through the FDA. They found a host of increased risks associated with the use of BMP during fusion procedures, one of which was cancer.
The Good News
A more recent study contests this result. The study of 4,700 patients receiving spinal fusion with BMP showed no increase in cancer risk compared with people with non-BMP fusions. The researchers found no significant difference between subsequent cancer development rates for each group (9.37% and 7.92%, respectively).
The Bad News
While that’s good news for people who have received spinal fusion with Infuse or are considering it, it’s important to note that this study found participants operated on with BMP to have a 31% higher rate of benign tumor development. While these tumors aren’t cancerous, “benign” doesn’t necessarily mean “innocuous.” Benign tumors in the spine and meninges – the tissue surrounding the spinal cord and brain – can cause other symptoms, like spinal pain and nerve impingement.
Another factor to consider is that some of this study’s participants were followed for as little as 2 years post-surgery; long-term cancer risks were not assessed.
Read more on the study at http://www.ncbi.nlm.nih.gov/pubmed/23756740.
Finally, Carragee et. al. found many other risk factors associated with BMP besides a potential cancer risk, including a 10-50% increased risk of male sterility, urinary problems, bone repair problems and inflamed nerves in patients who received BMP in the lumbar spine. Those who had BMP placed in the cervical spine had an increased risk of serious and life-threatening adverse events of 40%.
See more on Carragee’s research at http://med.stanford.edu/ism/2011/june/carragee-spine-0628.html.
While more research may confirm or deny some of Carragee’s results, it’s important to know all possible risks of a treatment before you pursue it. You may expect your medical professionals to inform you off all the risks associated with your procedure, but keep in mind that Infuse was approved for use as far back as 2002, 9 years before Carragee’s research surfaced; your doctors may not be apprised of the risks. Given the potential risks associated with BMP, it’s likely a good idea to talk to your surgeon about alternative methods of spinal fusion.