Janice Tehie was cooking dinner on Labor Day weekend nearly two years ago when she felt something near her left knee. At first Tehie thought she had splashed water down her leg. She looked closer, horrified, as blood and fluid leaked down her shin from a failing suture near her kneecap, continuing a medical nightmare that spanned 10 months, three hospitals, three knee replacement surgeries and two doctors.
By the following April, an FBI agent was interviewing Tehie about her orthopedic surgeon, Stephen Engstrom, formerly of Vanderbilt University Medical Center, who made the decision to put a DonJoy implant in her left knee. Law enforcement confirmed that a federal investigation into VUMC is ongoing and declined further comment.
As opposed to custom-fitted products like Zimmer and Stryker, DonJoy is a presized option from medical device corporation Enovis. Tehie can compare — she says she’s had no issues with the custom-fitted Zimmer in her right knee, done by a surgeon in Vermont in 2023 before she moved to Jackson to be closer to family. She tells the Scene her new DonJoy failed in just weeks — sized too small, it slid out of place and subsided into Tehie’s tibia, forcing a second surgery by Engstrom in late June. Tehie says an abscess due to a poor suture job sent her back to Engstrom’s operating room and onto intravenous antibiotics. Tehie says that over the next few months, more pain and nerve pressure made physical therapy impossible, prompting her to seek medical advice outside of VUMC. This second DonJoy was too big according to another surgeon, who replaced her knee for a third time in March 2025.
“When I asked Dr. Engstrom about using DonJoy on the left knee, I got this strange answer, a long diatribe about how he didn’t like using robotic surgery systems because it was making the decisions for him,” remembers Tehie. “I thought at the time that it was a strange thing to say. I wish fervently I had gone with my misgivings and gone with someone else. I thought maybe it was just his manner.”
Engstrom, along with fellow VUMC orthopedist Greg Polkowski, left VUMC on Friday, July 31, according to information shared with patients. By Aug. 1, both doctors' profiles had been removed from VUMC's website. The two have received more than $670,000 in legally reportable payments from Enovis and DonJoy since 2019, though individuals familiar with the industry estimate that these doctors received more. Tehie says she knows of at least 10 other people like her, suffering from complications after a knee replacement at VUMC and looking for answers.
A lawsuit filed in March 2024 alleged a kickback scheme in VUMC’s orthopedics department. The plaintiff, Dr. Chris Hoedt, said he was pressured by Polkowski to use DonJoy products, which he deemed “subpar” for patients. Hoedt and VUMC, namely lawsuit defendants Polkowski and senior orthopedics department Dr. Rick Wright, settled their dispute as of June 3, 2026, according to documents filed in federal court.
Questioning has focused on VUMC orthopedics department, according to those interviewed by federal agents
Patients say they can no longer access the messages announcing the departures of Engstrom and Polkowski. In some cases, previous correspondence about appointments and certain medical records are no longer available via VUMC’s online MyHealth portal. The medical group — Middle Tennessee’s largest employer — did not respond to the Scene’s multiple requests for comment. Both physicians' public contact information directed back to VUMC.
“I’m just mad — really mad — I liked Dr. Polkowski and I trusted him with my life,” another patient, who receives ongoing care at VUMC and asked to remain anonymous, tells the Scene. “I understand you don’t get back to 100 percent after a knee replacement, but my DonJoy knee is painful every day. It’s swollen every day, and there are popping noises like it broke.”
Osteoarthritis forced this patient to replace both knees. Like Tehie, she has a custom-fit implant, a Stryker, in her right knee, installed by Polkowski in 2018. She was confused when she returned in 2021 and a Stryker implant was no longer an option. After being notified earlier this summer that Polkowski would leave on July 31, this patient asked a nurse for more information at a follow-up appointment. The nurse confirmed that the termination was due to a legal issue. She wants the full story.
“I’m just so angry that I was sold out for money,” the patient tells the Scene. “What pisses me off is Vanderbilt covering this up. I don’t want a dime, I want them to say, 'Our doctor screwed up and we’re sorry.' I want an apology. And I want to find Dr. Polkowski, wherever he is, and ask, ‘Was this worth it?’”
