Caitlyn Jenner's mother has broken both her hips.

The 'I Am Cait' star, 65, has revealed her mum Esther has fractured her upper thigh joints but is ''doing great'' and is trying to be as ''mobile'' as possible to speed up recovery.

Taking to her Twitter account last night (12.10.15), Caitlyn shared a snap of herself standing behind her mum - who was sitting in a chair smiling - along with the caption: ''Visiting my mom and she's doing great after breaking both her hips. She's been mobile - she's tough (sic).''

The pair have kept a close bond over the years but Esther recently admitted she struggled to come to terms with the news Caitlyn - who was formerly known as Bruce Jenner before her gender transition surgery earlier this year - was transgender and was scared she'd ''lost'' her son.

Esther, 88, said: ''My first feeling was, 'I lost my son'. Then I thought, 'You know what? I'm gaining.'''

Caitlyn unveiled her new identity on the cover of Vanity Fair magazine in June and said recently she has no regrets ''whatsoever'' about her drastic change.

The stunner - who has been married three times, including to Kardashian matriarch Kris Jenner, and has six children - has even found a big advantage to being a woman - her new breasts have apparently made her better at golf.