In July, the official journal of the North American Spine Society, The Spine Journal, released an issue dedicated to the use of recombinant bone morphogenic protein. The only BMP product on the market currently approved by the FDA for promoting spinal fusion is Medtronic's Infuse, which has been the gold standard in BMP use since it was approved in 2003. Now, surgeons and researchers are raising questions about its efficacy in off-label use because additional studies have linked it to complications, including retrograde ejaculation in male patients.

The use of Infuse even among on-label applications has recently come into question as well because some feel the field is lacking evidence-based literature proving BMP creates better outcomes. Without solid backing from strong studies, hospitals and insurance companies are hard-pressed to approve the use of Infuse, since it is considerably more expensive than the alternatives.

A study of 1,037 patients who received recombinant bone morphogenic protein-2 to promote fusion in a posterolateral application shows the procedure is a safe and effective treatment for patients, according to a report published in Spine.

Scaffolds loaded with low-dose recombinant bone morphogenic protein-2 is comparable to autograft bone as a bone graft substitute for anterior lumbar interbody fusion in a large animal model, according to a study published in Spine.

A retrospective analysis of fusion cases submitted by the Scoliosis Research Society over three years showed that bone morphogenic protein use with anterior cervical fusion increases the incidence of complications, however BMP use isn't associated with more complications during posterior and thoracolumbar cervical fusions, according to a report in Spine.

In June, Eugene Carragee, MD, editor-in-chief for the North American Spine Society's The Spine Journal and a spine surgeon at Stanford University School of Medicine, co-authored an article showing that the use for recombinant bone morphogenic protein was associated with retrograde ejaculation among male patients, which could cause infertility. The study, published in The Spine Journal, was surprising for many spine surgeons who had been using Medtronic's Infuse, an rhBMP-2 product, with patients for spinal fusions over several years because they weren't aware of the complication risks. At the same time, the articles' authors revealed that while Medtronic reported complications of RE to the FDA for clearance, the data about these complications was not made available for the public in peer review articles sponsored by Medtronics.

Medtronic has given a $2.5 million grant to Yale University to independently review the safety and effectiveness of its rhBMP-2 product, Infuse, which has recently been associated with more complications than initial company-funded studies reported, according to a North American Spine Society news release.

The feud between spine surgeons who were involved in the research and development of Medtronic's Infuse and the surgeons who feel the product was inappropriately marketed continues to escalate, according to two letters set for publication in the July 12 issue of The Spine Journal.

A critical review of 13 industry-sponsored studies on recombinant bone morphogentic protein-2 found that the actual risk of adverse events was 10-15 times higher than the study estimates originally reported, according to a release from the North American Spine Society.

Omar Ishrak, chairman and CEO of Medtronic, responded to a series of articles attacking the company's original trials and promotion of recombinant human bone morphogenic protein-2, saying that integrity and patient safety are his highest priorities, according to a company news release.