A federal judge in St. Louis has ruled against a key argument in a Medtronic lawsuit. The ruling applied to the assertion that the Infuse Bone Graft System is a defective medical device.

The Infuse Bone Graft System is a medical implant. It is designed to help perform spinal fusions, a type of surgery designed to repair a specific type of spinal damage. In a healthy spine, cushions of connective tissue called spinal discs support and protect the spine. But age, injury and disease can impair the function of these discs, a condition called degenerative disc disease.

Surgeons treat degenerative disc disease by joining individual backbones together to strengthen them and compensate for the failing disc. This procedure is called a spinal fusion surgery. The Infuse Bone Graft System is designed to help make this procedure easier. However, Infuse lawsuits allege that the Infuse Bone Graft System is dangerous and illegally marketed.

In this particular Infuse lawsuit, the judge has ruled that the claim that the device was defective was preempted by the FDA’s approval. The judge ruled that FDA approval shields Medtronic Inc., the Infuse Bone Graft System’s manufacturer, against claims that the device is defective.

Under federal law, a person or company is not liable for harms they’ve caused if they’ve performed due diligence, or made a good faith effort to prevent their actions from causing harm. The judge ruled that performing FDA-mandated testing on the device satisfied its due diligence and obligations under the law. However, the case was allowed to move forward on other allegations.

Many Infuse lawsuits hinge on the allegation that Medtronic illegally promoted the Infuse Bone Graft System for off-label use. Under federal law, FDA approval is very specific — a medical device maker must separately test a device for every use they plan on promoting the device for.

In cases where medical literature outpaces the FDA’s approval process, a surgeon may make a judgment call and use a device “off-label” or for purposes other than the FDA-approved use. However, medical device manufacturers are strictly forbidden from promoting a medical device for off-label purposes.

Infuse lawsuits have alleged that Medtronic aggressively promoted the Infuse Bone Graft System for off-label use.

Allegedly, Medtronic embarked on a clandestine campaign of promotion for the Infuse Bone Graft System. Medtronic has allegedly hired “opinion leaders,” prominent physicians to write research papers or give speeches at medical conferences promoting off-label uses for the Infuse Bone Graft System. Allegedly, this included key medical experts at the University of California, Los Angeles and Walter Reed Army Medical Center who received tens of thousands of dollars for their work — which was not disclosed to the public.

The Infuse Bone Graft Lawsuit is Kathleen Arthur v. Medtronic Inc., Case No. 4:14-cv-00052, in the U.S. District Court for the Eastern District of Missouri.