Spinal cord stimulators—implantable devices designed to deliver electrical pulses to the spinal cord to block pain signals—have become a cornerstone of chronic pain management. But behind the promise of relief lies a mounting wave of litigation that is reshaping the landscape for device manufacturers and raising fundamental questions about how these products are regulated.
Behram Parekh, an attorney at Wisner Baum who represents plaintiffs in spinal cord stimulator litigation, explained that, as per the lawsuits, research shows spinal cord stimulators are effective for up to three months. “If you ask someone, do you want to go through all this surgery and stuff because it will help you for three months, they’re going to say no,” he said.
The litigation, which Parekh described as having been under investigation for several years, has accelerated significantly in the past year. On June 5, the US Judicial Panel on Multidistrict Litigation (JPML) issued a pivotal order centralizing 14 actions against Boston Scientific Corp. in the US District Court for the Central District of California. Judge Josephine Staton was appointed to oversee the consolidated docket.
However, the panel declined to create an industry-wide MDL encompassing Abbott Laboratories and Nevro, despite plaintiffs’ requests. Medtronic, which also makes spinal cord stimulators, was not included in the MDL petition. The decision was rooted in technical considerations rather than an assessment of the merits of claims against other manufacturers, said Parekh.
Parekh explained the reasoning: “The panel held in its order that there are enough differences between the devices manufactured by the different companies and the way their applications went up through the FDA, the changes they submitted to the FDA, that they didn’t believe having an industry-wide MDL made sense.”
He said that manufacturers argued trade secret issues would “really end up forcing the court to separate these out anyway.” All manufacturers opposed the formation of an MDL. However, Parekh indicated that plaintiffs intend to file renewed petitions for separate MDLs for Abbott and Nevro.
Understanding The Regulatory Controversy
At the heart of the litigation is a dispute over how spinal cord stimulators have been approved and modified through the FDA’s regulatory framework. These devices are Class III medical devices, subject to the FDA’s premarket approval (PMA) process—the agency’s most rigorous review pathway.
The original PMA for some spinal cord stimulators dates back decades. Medtronic’s initial approval, for example, was granted in 1984. Since then, manufacturers have submitted hundreds of PMA supplements to modify device software, capabilities and design.
Plaintiffs allege that manufacturers have abused this supplement pathway to avoid the rigorous clinical trial requirements that a new PMA would demand. “The lawsuit allege that these devices don’t look anything like the devices that were originally approved, don’t act the way those original devices were approved, aren’t programmed the same way,” Parekh said.
The theory in the lawsuits, as Parekh described it, is that manufacturers have made “numerous changes” over such a long period that they have “essentially sort of completely change[d] a device from start to finish.” Lawsuits contend that each of these changes, while described by the manufacturer as minor individually, collectively represent a substantial modification that should have triggered new safety studies.
A May 2025 lawsuit, the Dena Lawler case, filed against Boston Scientific and the FDA in the US District Court for the Central District of California, alleged that the company “improperly used the premarket approval supplement pathway” to implement substantial device modifications, filing over 300 supplements for the Precision system alone.
The plaintiffs are pursuing two main legal tracks. One involves failure to warn—alleging that manufacturers knew or should have known about risks but failed to inform patients and doctors. The other involves design defect—claiming that the devices were inherently defective due to battery instability, lead migration, programming issues or faulty firmware.
Some lawsuits have gone a step further, naming the FDA as a defendant under the Administrative Procedure Act. Parekh explained that plaintiffs have filed declaratory relief actions alleging “that if an agency does not follow its own rules and regulations, you can bring an action to enforce that and force the agency to actually follow the procedures that it set out.”
Parekh explained the goal of these claims: “We just want them to go back and review all of those and make a decision. I mean, they could come back and say, no, we’ve looked at all of these and these devices are fine. Or they could say, no, they should do a safety study.”
The Australian Precedent
While the US litigation continues to unfold, regulators in Australia have already taken significant action. In August 2024, Australia’s Therapeutic Goods Administration (TGA) ordered the removal of several spinal cord stimulator devices from the Australian Register of Therapeutic Goods. The TGA said “the sponsor provided insufficient information to demonstrate compliance with the essential principles.” The action resulted in 12 devices being canceled from the register and another 70 having conditions of supply imposed, meaning these specific models cannot be implanted into new patients unless manufacturers meet rigorous ongoing safety and evidence standards (including new clinical data). While this did not constitute a full recall—existing stock could still be used—new patients could no longer be offered the affected devices.
Christian Simmons, a reporter for Drugwatch.com who tracks dangerous product litigations, said that lawyers may point to Australia’s actions as evidence that other regulatory bodies have taken the risks seriously. However, he cautioned that “just because of the way the world’s set up and the way laws play out, it’s not necessarily like you can’t just go in with a lawsuit and say, well, Australia did this, so that means that the US should have done too.”
Parekh confirmed that plaintiffs have included references to the Australian regulatory action in their complaints.
The Bellwether Process
With the MDL now established, the litigation will proceed through a structured process designed to efficiently manage what could become hundreds or thousands of individual cases.
Simmons explained that MDLs work toward selecting “bellwether trials”—typically two to 10 cases that are considered representative of the wider group. These cases are prepared for trial while the vast majority remain on hold.
“Instead of preparing say 200 cases for trial, which would take an incredible amount of resources, you just prepare those five or six,” Simmons said. The outcomes of these bellwether trials often determine the trajectory of the entire litigation. If plaintiffs win significant verdicts, manufacturers are likely to negotiate a global settlement rather than risk more trials.
Parekh elaborated that the number of bellwether cases typically depends on the diversity of injuries involved. For spinal cord stimulators, he identified “three sort of buckets of injuries”: those caused by electrical waveform issues leading to nerve damage, those caused by battery problems, and those caused by lead migration or breakage.
Both sides are expected to line up expert witnesses to support their claims—a process that can become contentious.
“It gets crazy as you get deep into these litigations,” Simmons acknowledged. Each side will try to “poke holes in the other’s arguments” and “throw everything they have to explain why whatever conclusions the other side came to don’t make sense.”
The presiding judge will ultimately decide whether expert testimony is admissible. If plaintiffs’ experts are excluded, cases are unlikely to proceed to trial. If admitted, juries will then decide whether to credit the experts’ conclusions.
Parekh emphasized that independent academic research—not just manufacturer-sponsored studies—has raised concerns about device safety. “Those studies form the basis for our being able to actually allege that these devices are not safe,” he said. He noted that manufacturers are supposed to provide such studies to the FDA, though it remains unclear whether they have done so.
Company Responses
Boston Scientific: “Because this is an active legal matter, we intend to address this matter through the appropriate legal process and do not have further comment.”
Abbott: “We stand behind the safety, quality, and performance of our spinal cord stimulation systems. These technologies help manage chronic pain and provide meaningful relief, improving patients’ overall quality of life. They are highly regulated medical devices that have been approved and updated in accordance with federal law through the FDA’s rigorous premarket approval and supplement processes. We strongly disagree with the allegations in this lawsuit and believe they are without merit.”
Medtronic and Nevro did not provide comments for this article.
