Jenna Frerichs said her surgeon thought of her like a daughter.

The pair had known each other for more than a decade after Dr Mark Sanders, an orthopedic surgeon who specializes in foot and ankle surgery at his clinic in Houston, Texas, fixed her right knee following a volleyball injury in 2013.

So, when Frerichs, who is based in Chicago, started to suffer mild pain in the same knee 10 years later, Dr Sanders felt like the obvious person to help her.

A 34-year-old fitness fanatic and finance worker, Frerichs regularly spent her weekends hiking, on five-mile runs or working out in the gym. So, when her right knee started to hurt again, she told Daily Mail she feared that if she did not act quickly, the pain would worsen and limit her daily movements.

After hours of research and calls with the doctor in 2023, Frerichs, as claimed in court filings, agreed to an arthroscopy, a common procedure, with about 1 million carried out in the US every year, where surgeons make a tiny incision in the knee to remove tissue or bone that may be causing pain.

She had the surgery in February 2023 and said she woke up to a much larger incision than expected. The post-op report, which Frerichs showed to Daily Mail, said that 'no complications or blood loss occurred' during the operation. 

Yet, when Frerichs saw her knee herself after surgery, she was shocked to find a four-inch scar, much larger than the small puncture incisions typical of an arthroscopy, across her knee. 

In an interview with Daily Mail, she said that, as the anesthesia started to wear off, she felt pain that was much worse than before the surgery or even after her injury in 2013.

Frerichs said she had expected only slight pain and to be on crutches for three to four days. Instead, she said she was on them for nearly two months and she says the pain was persistent. 

Every time she took a step, she said she felt a 'catching sensation' in her right knee and then a sharp pain.

In court filings, she said the surgery left her with 'radiating leg pain' and a 'popping and clicking sensation' in her knee whenever she tried to walk.

Frerichs added to Daily Mail: 'My life split into before and after that surgery.

'I thought I’d wake up with the same knee I walked in with. Instead, I woke up to a future I didn’t recognize, one marked by pain, physical limitations, and a loss I’m still learning to live with.'

She continued: 'Before the procedure, I was fully active and had no pain in my normal day-to-day life. The only thing I ever noticed were occasional, brief twinges in my kneecap during very specific situations like going downstairs in heels or during a deep lunge, and even that never stopped me from doing anything.

'I didn’t want to lose the active life I had. When I asked what would happen if I did nothing about the occasional kneecap pain, I remember the surgeon telling me I’d "probably need a knee replacement in my early forties". That terrified me, and it strongly influenced my decision to proceed.

'I consented to what I believed would be a straightforward arthroscopy, but I woke up to something far more involved than I expected. It was shocking and confusing.'

Daily Mail contacted Sanders, of the Sanders Clinic, ahead of the publication of this article, but did not receive a response to requests for comment. 

In a court paper in response to the lawsuit, Sanders denied all allegations and said no complications occurred during the surgery. In his deposition, he said the procedure was carried out on the scar from the previous surgery to limit additional scarring.

Frerichs said she raised concerns over her pain with Sanders at their post-operative meeting the next day, but claimed that her surgeon told her he was not concerned about the pain and that it would ease. 

Frerichs added that she and Sanders exchanged text messages and phone calls to discuss her pain.

She told Daily Mail that she later raised concerns over the size of the incision in her knee after consulting with second- and third-opinion surgeons.  

Court filings state that in April 2023, after the pain had not eased, she had a follow-up arthroscopy with a second surgeon, that was investigative, to try to determine whether something went wrong with the first procedure.

Reviewing this surgery, Dr Stephanie Stephens, an orthopedic surgeon who provided the plaintiff with an expert report on the case seen by Daily Mail, said that the surgery found there was bone missing from the knee. 

She added that a small metal fragment was retrieved from the knee, which was described as large enough to require tweezers to extract.

It was not clear how the metal came to be in the knee, and whether it was linked to the February 2023 surgery or any previous procedures.

Reviewing Frerichs' surgery with Sanders, Stephens added that it was not clear how an arthroscopy had led to such a large incision.

She said an incision of this size suggested Frerichs had, instead, received an arthrotomy, not the procedure Frerichs requested and a less common operation where a whole joint is opened to allow surgeons visual access to the internal structures for inspection, diagnosis and repair. 

This surgery is more commonly used for patients with arthritis or who are suffering serious pain from the joint.

In Sanders' post-operative report, according to court filings, he writes that there were no complications in the surgery. He also states that the procedure lasted for 47 minutes.

In her expert report, Stephens notes a difference between this and the report from the operating room nurse, who, she wrote, said the operation lasted for 72 minutes. 

After the second arthroscopy in June 2023, Frerichs told Daily Mail she had a cartilage and bone transplant in August 2023 to try to reconstruct her joint. 

She said this stopped her suffering from the 'catching' sensation and shooting pain, although she still suffers pain from activities. 

She added that running, one of her favorite sports, remains all but impossible.

Frerichs filed a medical malpractice lawsuit against Sanders in April 2024, alleging she had received an unauthorized procedure and harm.

Sanders' legal team offered her a settlement in May 2025, after the doctor made his deposition, of $200,000, providing that she sign a non-disclosure agreement that would have barred her from talking about the case.

She refused, telling Daily Mail that she wanted to use her voice to highlight the shortcomings of Texas' medical malpractice law.

In the state, it is not possible to sue a doctor for non-economic damages, those that are not medical bills or lost income, for more than $250,000.

Frerichs is now fundraising to get her case brought to trial by jury, and has so far raised $7,475 of the $25,000 goal. The deadline is January 8, 2026.

Sanders has denied all allegations against him. In his deposition, seen by Daily Mail, he said: 'But you see, what you seem to misunderstand is, that this knee was not opened. This was not an opened arthrotomy of her knee.

'All we did was, we made the skin incision, moved the skin over, and then made all our holes so Jenna didn't have to have a whole bunch of more, a whole bunch of more portals and more scarring.

'So, this was not an open, this was not an open surgery. It was an arthroscopic surgery. The only difference was, was that rather than giving her five or six new incisions, we used the old scar and moved the skin over, not the cartilage, not the whole leg, just the skin over.'

Frerichs added: 'I sued because I still don't feel like I know what happened to me while I was under anesthesia. That's what makes this so painful.'

She added: 'I was naive when I started this process. I thought the justice system was there to deliver justice. I really thought it was there to get to the truth. Instead, I feel like it wanted silence.

'For me, it’s never been about the money. It’s about justice, transparency, and trying to make something meaningful out of something that was honestly devastating and life-changing.' 

Speaking about the impact the surgery has had on her life, Frerichs said: 'Before all of this, movement was very much a part of my identity. It was my outlet, my joy. Losing that has been devastating. So much is limited now or comes with pain.

'Even simple things like taking the stairs can trigger pain now. It feels like losing a piece of who I was, and I’m still grieving that, still trying to adjust to what my new normal looks like.

'Even after the revision surgery, everything is different. 

'I still deal with chronic pain, swelling, difficulty with stairs, and activity restrictions I never imagined facing in my early thirties, especially as someone who used to be so active.'