The judge overseeing the Medtronic Infuse bone graft litigation is considering a motion by Medtronic Inc. to throw out 21 lawsuits.

Medtronic has argued that the 21 cases alleging problems with the company’s Infuse Bone Graft System were preempted by an earlier court ruling. Medtronic has already agreed to pay out $22 million to settle 950 claims against them, and is budgeting up to $140 million to resolve additional litigation over the Infuse Bone Graft System.

The Infuse Bone Graft System is a medical implant designed to help surgeons in spinal fusions. This procedure is used to strengthen the spine when a patient’s back is injured or wears out. In older spinal fusions, surgeons would harvest redundant bone from elsewhere in the body and use it to fuse two adjacent spinal bones together. The Infuse Bone Graft System was designed to save a step in this process by using a bioengineered gel instead of harvested bone to encourage the bones of the spine to grow together. However, Medtronic lawsuits have alleged that the Infuse Bone Graft System is inherently dangerous.

Infuse lawsuits have alleged that the device can cause a host of medical problems. The medical problems attributed to Infuse range from trouble swallowing to cancer. Many lawsuits have alleged that the bioengineered gel can cause overgrowth of new bone, causing bone spurs and nerve damage as the new bone growth damages surrounding tissue. Infuse lawsuits have alleged that complications from the Infuse Bone Graft System can be crippling and life-threatening.

Another key element of the Infuse litigation is that Medtronic Inc., the device’s manufacturer, has allegedly promoted the device for off-label use. Under U.S. law, makers of a drug or medical device must seek U.S. Food and Drug Administration (FDA) approval for each specific use. The Infuse Bone Graft System is only approved for spinal fusions in the lower back. Physicians are allowed to use medical devices and drugs “off-label” or for purposes beyond their FDA approval when new research suggests a device can help other conditions. But the manufacturers of drugs and medical devices like the Infuse Bone Graft System are prohibited from promoting such uses without submitting their wares for further FDA approval. It is alleged that Medtronic Inc. vigorously promoted the device, going as far as to ghostwrite scientific papers supporting its use.