A father-of-three died while taking part in a clinical trial during knee surgery, an inquest has been told.
Luigi Belcuore, from Morton Bagot in Warwickshire, had agreed to the trial while having elective surgery on his right knee to repair cartilage damage.
But he suddenly died during the operation in October 2009 at Oswestry Orthopaedic Hospital in Shropshire, the jury heard.
The 43-year-old may have suffered an air embolism, the inquest was told.
He died almost instantly.
Coroner John Ellery told the inquest at Shrewsbury Magistrates Court, Mr Belcuore had been fit and healthy but was having problems with his right knee.
He had been taking part in a 10-year trial which involved growing cartilage cells inside damaged knees.
Mr Belcuore had a small hole or lesion in his cartilage.
Surgeons at Oswestry were trialling growing a patient's own cartilage cells inside their lesions to see if the long term outcome was better than other treatments.
The problem came when surgeons tried to get the blood to clot, the inquest heard.
Air was pumped into the knee to dry the blood, which surgeon Professor James Richardson said was not an unusual or particularly risky thing to do.
The hearing, at Shrewsbury Magistrates' Court, has been adjourned until Tuesday.
