The jury trying two people accused of kidnapping Shannon Matthews was told on Monday that one of the defendants was too ill to attend court.
Michael Donovan, 40, of Lidgate Gardens, Batley Carr, West Yorkshire, was attacked in prison on November 13, Leeds Crown Court has heard.
Donovan and Shannon's mother, Karen Matthews, 33, both deny kidnap, false imprisonment and perverting the course of justice.
Jurors were told the trial would not sit on Monday due to Donovan having surgery on a fractured jaw at the weekend.
Mr Justice McCombe told the jury on Monday morning that Donovan was in a "rather bad way".
He said: "You will note there is one person missing from the dock.
"We all know what happened to Mr Donovan about a week or so ago.
"Just before the weekend set on, we heard that the medical opinion was he had to have immediate surgery. That has been done on Saturday morning."
The court has heard how Shannon, who was nine at the time, was found in Donovan's flat 24 days after she went missing from her home in Dewsbury Moor, West Yorkshire, in February this year.
The prosecution allege that Donovan kept her drugged and imprisoned in his flat as part of a plan he and Matthews had to claim £50,000 in reward money.
