THE worst may be behind him but little Isaac Jones faces another hurdle that could see him go under the surgeon's knife again on Tuesday.

Isaac was born with an enlarged skull. Six months ago surgeons took his skull apart, resized it, and put back together like a jigsaw puzzle.

The surgery, which was pioneered at the Royal Children's Hospital, is now being followed around the world as "the Melbourne procedure".

The seven-hour operation relieved pressure on Isaac's brain, prevented any developmental delays, and made him look normal.

Mum Lisa Jones said the 18-month-old, who is the poster child for the hospital's 2010 Good Friday Appeal, had developed wounds that would not heal.

They were the size of 10c pieces, with one appearing on top of his head five weeks ago and another last week.

RCH plastic surgeon David Chong said the wounds were probably caused by the dissolving sutures used after his surgery.

But it was likely the Shepparton toddler would have minor surgery today to determine exactly what was causing them.

"We're happy with his head shape and with his progress," Mr Chong said.

Dad Troy Jones said Isaac bounced back strongly about three weeks after the original surgery.

"All of a sudden it was just like a light switch went on, everything clicked, and he was back to his happy little self," Mr Jones said.

"He was starting to progress, he was starting to learn, he was talking, he doesn't shut up.

"He's full of beans, he's full of life, and he has no idea of what he's been through."

Appeal director Christine Unsworth said funds raised this year would go towards research and new surgical equipment.

Last year, the Appeal raised a record $13,862,734 from the Victorian community.