Since 2002 surgeons have had a special tool in their box of techniques for spinal fusion. And that is a substitute for bone graft called bone morphogenetic protein or BMP. Although more expensive, this product has two major advantages over bone taken from the patient: 1) patients no longer suffer pain and discomfort at the pelvic crest where donor bone has been taken from and 2) patients with poor bone growth due to diabetes or tobacco use can have a spinal fusion when necessary.
But now some serious complications and post-operative problems have been reported. So it’s time to take a second look at the safety of this bone substitute product. BMPs were first discovered in 1965 with more than 20 types now being studied. Only one (BMP-2) has been approved for use by the Food and Drug Administration (FDA) in spinal fusion surgeries.
When used as it was approved and intended, BMP stimulates safe and effective bone growth to aid in the fusion process. And that primary use for which it was intended is only anterior lumbar (low back) interbody fusion. Troubles begin when this product is used off-label such as for cervical (neck) fusion, especially anterior (from the front of the spine) procedures and posterior (from the back) lumbar fusion.
Massive soft tissue swelling, extra bone formation, seromas (fluid-filled pockets), and even cancer have been reported as emerging concerns with BMP-use. To aid surgeons in evaluating the real concern about BMP in spinal fusion, three surgeons from the University of Pittsburgh provide some perspective and insight into the safety issues that have come to light.
First, they suggest surgeons-in-training should all learn how to harvest and use iliac crest bone grafts. In other words, this type of self-donation should not be abandoned in favor of only using BMP. Second, BMP should be used as indicated until further studies expand its use. In other words, it should not be used as an off-label product. Third, surgeons are responsible to select patients carefully for spinal fusion. In other words, not everyone is appropriate for the primary surgical procedure. Surgical success is more likely when used for the right patients.
And finally, until perfected through studies, BMP should NOT be used in anterior cervical spine patients and certainly not for anyone who has a past (or current) history of cancer of any kind. Using BMP for the ease and convenience of the surgeon is not acceptable when there are safety concerns and risks of serious harm to the patient.
In summary, BMP has a high rate of fusion when used as intended (for lumbar spine fusions). But there is no evidence or proof of any kind that BMP is better than patient donor bone from the iliac crest in terms of fusion rate or outcomes (decreased pain). More long-term studies are needed before expanding the use of this product, to identify those procedures in which its use is both safe and effective, and to document potential complications.