There are growing fears for Ozzy Osbourne after the music legend dropped out of an appearance at a horror and sci-fi movie convention in the US this weekend for health reasons.

Osbourne’s wife and manager Sharon Osbourne announced Ozzy had to pull out of the Mad Monster Party Arizona 2024 — due to be held from Friday to Sunday in Phoenix — as he was “unable to travel at this time”.

“We would like to thank you all for your constant support with Ozzy,” she said making the announcement last month.

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“It means so much to him, you have no idea. All I can do is apologise that we won’t be there.”

The Black Sabbath frontman had been due to appear with his family for a meet-and-greet package being sold for $US666 ($A988).

The couple’s son Jack will attend on the family’s behalf — but fans are worried as there has been no update on Ozzy’s health since the announcement.

“I’m apologising to people we’ve let down, from my heart,” Sharon said earlier.

Concerns for Ozzy’s health were heightened Hollywood actress Sharon Stone was seen asking Sharon Osbourne how her husband was doing, as the pair greeted each other on the red carpet at The Bikeriders premiere in LA last month.

Video of the greeting shows Sharon Osbourne shaking her head, with Stone responding: “I’m so sorry.”

Ozzy lives with Parkinson’s disease since being diagnosed in 2003 and has had several other health scares in recent years.

The singer last year announced his retirement from touring, citing problems with his spine — which he injured during a 2019 fall that aggravated a spinal injury he suffered in 2003.

Earlier this year, he underwent a fourth spinal surgery which “virtually left me crippled”.

“I thought I’d be up and running after the second and third, but with the last one they put a ... rod in my spine,” he told Rolling Stone UK in December.

“They found a tumour in one of the vertebrae, so they had to dig all that out too.

“It’s pretty rough, man, and my balance is all f***** up.”

His declining health has taken a toll on his family, Sharon told the publication.

“It’s been nearly five years of heartache and at times I’ve just felt so helpless and so bad for Ozzy, to see him going through the pain,” she said.

“He’s gone through all these operations and the whole thing has felt like a nightmare.”

At the time, Ozzy said he hoped to return to the stage for a final farewell show but, for now, was “taking it one day at a time”.

“If I can perform again, I will,” he said.