"He's going to miss the New Zealand Cross Country series and the Enduro Championship. But you know what? He will be back. He is not a giver-upperer. He will come back stronger."
Birch was not new to injury having broken bones before but Ms Roberts said he was on top of his fitness and normally didn't injure himself when he crashed these days because of this.
He also crashed during the final leg of the GNCC the week before but got back on to finish the race second and overall champion on points.
"He has had such good fitness ... he just fell the wrong way."
Birch came off at the top of a blind hill heading into a large drop. Doctors were at first worried about possible nerve damage so weren't able to operate until after a CT scan, she said.
"They have put screws and pins in place. He's just got to recover now. Hopefully, we will be home in a day or so."
Meanwhile, she is going to find it hard keeping him back from his bike. "He's just worried about his bike ... It was due for some maintenance anyway."