Thousands of patients in England have been left in "pain and discomfort" because of the decision to postpone operations, surgeons say.
The Royal College of Surgeons said those waiting for hip and knee surgery had been the worst affected.
Operations were put off this winter to free up beds for A&Es – and new figures have shown 40,000 fewer were done this winter than in the previous one.
Despite this A&E waits have hit their worst level for over a decade.
During the winter, just over 85% of A&E patients have been treated or admitted within four hours, well below the 95% target. This is the worst performance since the target was introduced in 2004.
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Royal College of Surgeons president Prof Derek Alderson acknowledged delaying operations was a "necessary evil" given the pressure A&Es were under.
But he said: "It also inevitably prevented many patients who are in discomfort or pain from having an operation when they needed it, potentially causing their condition to deteriorate."
As well as hip and knee surgery, the college said patients waiting for brain surgery for benign tumours that can cause sight problems if left and those needing treatment for conditions such as inflammatory bowel disease and Crohn's disease would also have been affected.
"We urgently need a clear plan to deal with the growing backlog of cancelled operations," Prof Alderson said.
Waiting for an op 'stops everything'
One of those caught up in the delays is teacher Scott Randolph.
He has been waiting for spinal surgery since November – and has already had his surgery cancelled once at the last minute.
He said his degenerative condition has left him in "excruciating pain" at times.
It has affected his ability to work and spend time with his two young children.
"I can't go out to play football with my son and I can't go horse-riding with my daughter.
"It stops everything."
Beds have been freed up – NHS bosses
The data published on Thursday by NHS England showed there were 544,000 operations carried out in December and January, down from 585,500 over the same period the year before.
It came after NHS bosses ordered hospitals ahead of Christmas to put off routine treatments amid signs A&Es were struggling.
NHS England defended the move to delay operations, saying it had helped free up 1,400 beds – the equivalent of two to three hospitals – over the winter months.
A spokesman said the number of patients affected was less than was initially feared at one point, but conceded it had been a "challenging winter".
And British Medical Association leader Dr Chaand Nagpaul warned the pressures were "far from over" with hospitals still incredibly busy.
"Patients are continuing to be routinely failed."
Pressures are also being felt elsewhere in the UK.
Waiting lists for hospital operations have risen in Scotland and Northern Ireland. And while they remain stable in Wales, the target to see patients within 26 weeks is still being missed.