Medtronic Inc., the medical technology company that manufactures the controversial Infuse bone graft, agreed in 2014 to pay $22 million to settle nearly 1,000 lawsuits over its product and set aside up to $140 million for future claims while maintaining that the company would vigorously defend itself in court.

Hailed as the next generation of spinal fusion, typically performed by harvesting bone from the patient’s hip, the U.S. Food and Drug Administration (FDA) approved the Infuse bone graft in 2002 for use in spinal fusion surgery, to fill in spaces where bone is needed.

Two years later it was approved for tibia repairs and later for use in dental procedures to repair the sinus cavity, facial surgeries and fusing damaged vertebrae in the lower spine. Believing it carried few side effects, doctors used it in a variety of other non-FDA approved, “off-label” procedures in the upper, cervical spine and other areas.

The Infuse bone graft is comprised of synthetic, concentrated proteins called recombinant human bone morphogenetic proteins (rhBMP-2) that are combined with collagen from cows and injected into the spine to alleviate pain. The synthetic protein makes it ideal for promoting bone growth.

Infuse quickly became an industry leader, snaring some 44 percent of the $1.9 billion bone graft market (allograft bone, cell-based matrices, bone substitutes and demineralized bone) and 90 percent of the bone morphogenetic protein (BMP) market.

But over the years, the Infuse bone graft has been linked to a variety of infections and complications, including an increased risk of cancer, excessive bone growth, paralysis, retrograde ejaculation, back and leg pain, swelling in the neck and throat, numbness, nerve damage, airway compression, difficulty breathing, swallowing and speaking, male sterility and other uro-genital injuries, and chronic pain.

So many plaintiffs have filed lawsuits against Medtronic that a federal judicial panel created a multidistrict litigation to centralize all of the cases in one venue before a single judge.

In addition to product liability lawsuits, Medtronic has been accused of paying doctors to use the product, intentionally hiding the possible side effects and using deceptive marketing practices.

According to MedPage Today, over the course of 15 years, Medtronic paid $210 million to a group of 13 doctors and two corporations linked to doctors, including more than $34 million to a University of Wisconsin orthopedic surgeon who co-authored a series of papers about the product.

As recently as April 2014, Medtronic has defended its product, saying that more than 1 million patients have used the Infuse bone graft since it came on the market. Medtronic vowed to “vigorously defend” the lawsuits in court.

A month later, the company announced that it had agreed with counsel representing 950 claimants to settle their inventories of filed and unfiled product liability claims related to the Infuse bone graft for $22 million, though Medtronic maintained that the settlement was not an admission of liability or validity of any defense in the litigation by Medtronic.

In its statement, Medtronic said there were approximately 750 filed cases brought by approximately 1,200 individual plaintiffs still pending in courts across the country.