Sanford Health and one of its most lucrative surgeons have been accused of defrauding the federal government out of millions of dollars while also harming patients in a stunning complaint filed in federal court.

The 111-page complaint, filed by two Sanford doctors in August 2016, was unsealed by a federal judge late Thursday. On Wednesday, the U.S. Attorney's Office for the District of South Dakota filed a motion to intervene in the case, bringing the specter of government sanctions and even criminal charges.

The lawsuit alleges that Dr. Wilson Asfora, a neurosurgeon with Sanford, defrauded the federal government by performing unnecessary spine surgeries. The complaint also alleges that Asfora and Sanford had an elaborate scheme in which Sanford bought medical devices from a company owned by Asfora, and that Asfora then implanted the devices in patients, creating an incentive to perform unnecessary surgeries and a violation of federal law.

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The court filing, brought by two of Asfora’s colleagues, Drs. Dustin Bechtold and Bryan Wellman, alleges that Sanford’s leadership ignored complaints from doctors and intentionally covered up Asfora’s surgical errors. It also alleges that Sanford and Asfora billed Medicare and other programs for care that was never provided. Those accusations, if true, could get the health system suspended from government health programs, including Medicare, resulting in hundreds of millions of dollars in lost revenues.

The filing says that Sanford’s executive leadership, including President and CEO Kelby Krabbenhoft, and doctors who were supposed to ensure patient safety, ignored repeated warnings and complaints that Asfora was performing unnecessary surgeries.

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Dr. Allison Suttle, Sanford's chief medical officer, denied the allegations in a statement to the Argus Leader.

"Dr. Wilson Asfora is an exceptionally talented surgeon who provides excellent care to his patients," she said. "His unique skills and expertise are a great asset to our region. He has saved the lives of hundreds of patients. The allegations in this lawsuit have been investigated and were found to have no merit. Sanford Health is confident in the care provided to our patients and will continue to provide quality care. We will vigorously defend this baseless suit."

At one point, in October, 2015, Sanford fired Asfora. The complaint says that Asfora ran into Wellman and another spine surgeon, Dr. Troy Gust, and told them he had "dirt and skeletons" on Sanford. Asfora predicted he would be reinstated, and he was two weeks later.

The complaint includes 50 pages of accounts in which Asfora is alleged to have performed unnecessary surgeries on patients. In those accounts, Asfora not only performed the surgeries, but he also filled patients with unnecessary screws and medical devices manufactured by his company, Medical Designs, that were then billed to the federal government.

Asfora and Sanford, the complaint alleges, received kickbacks by using medical implants in unnecessary surgeries. Medical Designs produced medical screws and spacers used in spinal fusion surgeries. The complaint alleges that Asfora used those devices on spinal fusion surgeries that were unnecessary in order to generate profits for himself.

“One level,” says a summary of one patient's fusion, “was all that was medically necessary for this patient. Dr. Asfora put in three additional cages, which this patient did not need, but which Dr. Asfora personally benefited from financially. Dr. Asfora never saw this patient prior to surgery. Three of these levels were off-label, medically unnecessary, and medically tainted by kickbacks."

It’s not the first time that Asfora and Sanford have been in trouble with violating federal anti-kickback laws. An Argus Leader investigation in 2014 revealed that Asfora formed an entity known as a Physician Owned Distributorship. PODs allow their doctor-owners to profit off of devices that they implant, which critics say increases the likelihood of doctors performing surgeries for financial gain.

Sanford and Asfora agreed to pay $625,000 in fines for violating anti-kickback rules.

Surgeons with the Orthopedic Institute had a separate POD, but they abandoned their POD amid concerns about violating federal law. Asfora continued his POD, which the complaint attributes to more frequent and aggressive surgeries performed by Asfora.