A Grantham man who was due to have a knee operation today says he found out on Facebook it had been cancelled as a result of Friday's cyber attack on the NHS.
Alan Challis says he's angry that United Lincolnshire Hospitals NHS Trust didn't contact him directly, as he had taken leave from work for the procedure and would have lost out on pay.
"My daughter texted me... there's something on Facebook from the United Lincs Hospital Trust to say that operations are cancelled.
"I feel aggrieved. I think that's the best way to describe it," he said.
The trust is one of a handful of trusts still affected by the ongoing problems.
In a statement this afternoon, chief operating officer Mark Brassington said the trust was still involved in a "major incident" and urged people to use accident and emergency wisely: "Significant progress has been made in restoring our IT systems following the cyber attack that hit our hospitals on Friday.
"We are asking all patients to attend their booked outpatient appointments and operations as planned tomorrow unless they receive a telephone call asking them not to attend, as some of our systems are still affected.
"Patients who do attend for their appointments are asked to bear with our staff, as some imaging and results may not be immediately available and systems are running slowly in some areas."