LONDON (REUTERS) — British rocker Ozzy Osbourne will be on a ventilator for at least one more day after fracturing eight ribs and a vertebra in a quad bike crash, doctors said Tuesday.

“We have begun, slowly begun, the process of getting him off the ventilator,” said Dick Jack, medical director of the hospital where the former Black Sabbath lead singer and reality TV star is being treated.

“Now, this can take several days, so there won’t be any major changes in his condition for the next 24 hours,” Jack told reporters outside the hospital.

“His progress is steady. He is stable. He is comfortable and satisfactory, but it’s going to be slow, and I don’t expect any major changes, certainly for 24 hours.”

Osbourne, who has mellowed from wild man of heavy rock to comical much-loved star of his reality TV series “The Osbournes,” underwent emergency surgery overnight after the crash on an all-terrain bike at his English country estate.

His wife Sharon made a 5,000-mile dash across the Atlantic Tuesday to be at his hospital bedside.

“I’ve not heard how he is since last night,” she told reporters as she arrived at London’s Heathrow airport. “I haven’t managed to speak to him on the phone, and I am going straight to hospital to see him.”

“I heard about the accident from my husband’s security guard. Apparently he was on his quad bike when he hit something and fell, and the bike landed on top of him.”

Osbourne’s tour manager Bill Greer told reporters later that Sharon and the couple’s daughter Kelly visited Ozzy, but he was unable to talk to them because of his condition.

“I know they spent some time just talking with him and being by his side,” Greer said.

“She really wanted me to wish thanks to everybody, all the well-wishers for all the messages, all the flowers, all the words of goodwill to Ozzy. It certainly means a lot to her, and it means a lot to Ozzy as well.”

Ozzy, 55, first shot to fame in the 1970s as frontman of the groundbreaking band Black Sabbath.

His viciously angry lyrics, gruesome stage stunts and disturbing images of evil earned the band cult status, and he gained notoriety by biting a bat’s head off at a concert in the United States. Ozzy has since said he thought it was a toy.

He is in Britain to promote his latest single, a soothing reworking of the Black Sabbath track “Changes,” which he sings as a duet with Kelly.

After the accident, bookmakers William Hill slashed their odds on the song topping the charts at Christmas, saying many people would buy it out of sympathy.