Monday, several patients filed a lawsuit against Duke University Health System, claiming negligence and fraud.
The lawsuits stems from an incident in late 2004.
An elevator repair crew working on a parking deck elevator drained the oil into empty detergent barrels and left them in the deck.
Someone at the hospital thought they had over ordered detergent and the barrels were picked up and later re-delivered to hospitals as detergent to wash surgical instruments.
Over a two month period, surgical instruments were accidentally washed in used elevator hydraulic fluid instead of detergent.
They were then used on nearly 4,000 patients.
Seventeen patients and their family members say Duke's response to the situation was evasive, deceptive and misleading.
They're suing for hundreds of thousands of dollars in damages each, and demanding a jury trial.
Patients are claiming that's what led to their ongoing medical problems.
In one lawsuit, a patient named Charles Harrison went to Durham Regional for hernia surgery. Days later he claims he experienced involuntary clenching of his fists. That he has numbness and tingling in his hands.
The same symptoms several patients told Eyewitness News they were experiencing back in 2005.
Months after their surgeries at Duke Hospitals with instruments washed in used elevator hydraulic fluid.
Most complained of gastro intestinal problems too --one, after back surgery, others after breast surgery and told Eyewitness News Duke kept information from them.
"I want to know, but I don't want to know because what if it's something bad ...(crying)… bad news that I can't handle," Debra Hooks, a patient from 2005 said.
Hooks is among the group of patients suing Duke - claiming Duke tried to cover up the ordeal; by not reporting the problem to the Department of Health and Human Services, by asking the Department of Labor to keep findings confidential, and by not telling Exxon --the maker of the fluid-- that patients were exposed to the oil during surgery.
Instead Duke said an employee got the oil on their skin.
Patients claim Duke destroyed evidence and only had a few contaminated instruments left for testing.
Analysis done on those instruments for Duke found "microscopic sterile residue on them." Yet in a federal investigation, a nurse stated the instruments were so greasy she had to change gloves several times.
Duke had an UNC doctor recreate the scenario and found that despite being washed in the fluid the instruments were fully sterile.
Another test that patients feel didn't paint the whole picture.
Still Duke stands by all the testing and tells Eyewitness News in part: "We can say with certainty that any exposure to the sterile instruments in question did not cause physical injury."
Words some patients disagreed with since the beginning.
"I just don't feel good. I don't want to go do a lot of things and that's not how I was before," Hooks said.
Duke has settled with other patients in previous suits. It is also suing other parties involved in the mistake.