Children's Health Ireland has said that three complex surgeries have been postponed at Temple Street for the next three weeks.
There were 32 children on the waiting list for spinal fusion surgery for scoliosis as of 19 August.
In a statement, Children's Health Ireland said all other spinal surgeries would continue during that three-week period.
However, Professor Adrienne Foran of CHI Temple Street Hospital in Dublin said that the three children have not yet been given a date as to when the procedures will take place.
Apologising for the postponement, CHI said: "The cumulative impact of undertaking a greater volume of these complex surgeries in recent months has resulted in pressures on beds, theatre capacity and on the highly specialised staff working within the service.
"The nature of these complex surgeries means that there are increased medical needs and a likelihood of longer stays in hospital for children and young people with complex conditions.
"Most complex cases require returns to theatre following their first surgery – this can range from 1-3 times usually or unusually, more than 20 times. These follow ups cannot always be planned for.
"Children's Health Ireland does not take lightly the decision to postpone any number of surgeries, affecting the children and young people we care for, and we are in constant contact with our families and patients affected to ensure they are kept informed of decisions and issues that may arise in our services."
Professor Foran told the News at One: "We don't want to overpromise. What we’re reviewing is our capacity for each one of them.
"We’re obviously very sorry that this has happened. It’s not a decision that we made lightly. Since April we’ve had a targeted approach to tackle the long waiting list of children with Scoliosis across all of CHI.
"It is just for the next three weeks and then we will work with the clinicians involved and plan how we re-schedule these children.
"This time last year we would have done one complex spine [operation] a month in Temple Street. Since April, we've been working really hard to do one a week."
The Children's Rights Alliance had called on Minister for Health Stephen Donnelly to explain the reasons for the cancellation of operations on children with scoliosis over the next three weeks.
Speaking on RTÉ's Morning Ireland, CRA Director of Legal Police and Services Julie Ahern said the children and their families were being left in limbo, which can have long term effects on their development and mental health.
She said more information is needed about the issues that have led to the cancellations.
Ms Ahern said the Government has an obligation to "tell these families what is happening".
Seven-year-old Brianna Phelan from Kilkenny is one of the children who has been told her operation, which was scheduled for next month, has been cancelled.
She has been waiting for back surgery for three years.
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
Brianna said she is living in pain every day.
"In my head and in my back every time, I have pain in my head, in my back, everyday and when I go to bed," she said.
Children's Health Ireland said, as of 28 August, Temple Street had undertaken the same number of spinal fusions in the year to date as were completed in all of last year.
It said it has 13 patients on the complex wait list remaining, with 31 spinal fusions on a waiting list.
CHI said it remained on track to deliver on the promise that, by the end of the year, no patient will be waiting longer than four months for spinal surgery if clinically appropriate.
It added: "Spinal fusions have been prioritised for theatre and bed capacity in Children's Health Ireland at Temple Street and less complex surgery has been supported by new additional capacity in Cappagh with 383 additional cases undertaken in NOHC year to date.
"The general inpatient and day case orthopaedic waiting list in CHI at Temple Street has reduced by 30% since January 2022 and we remain committed to ensuring every child on this wait list has timely access to the care that they need.
"329 spinal surgeries have been completed by Children's Health Ireland and Cappagh hospital so far this year."
