Rosie was born with a very rare disorder called spinal segmental dysgenesis. Five bones which made up part of her spine were missing, leaving a 10cm gap in her backbone. Her legs were also contorted up against her belly and she had very little feeling in them.
She was slowly running out of space in her chest - and running out of time. Eventually the internal crush would have led to Rosie's organs failing, which would have killed her. In her last scan before the operation there was evidence of her kidneys being crushed.
Rosie's legs were amputated from the knee down and a section of bone was taken to bridge the gap in her spine. Two metal rods were then bolted to the upper spine and the hips to provide extra support.
The operation at Birmingham Children's Hospital took 13 hours.
Her dad Scott said: "Before she was basically a timebomb - we never knew how long it would take to go off, we never knew how long we actually had with her. "Since having the op she's now had her life expectancy increased to that of a normal child." Since the surgery there have been early signs of sensation returning to her legs, which means it may be possible for Rosie to one day walk with prosthetic legs.
Her mum Mandy said: "Rosie is such a strong character. You give her the equipment to use and she'll do it, whether it's sticks or artificial legs or her hands - she'll make a way of walking. "All she has ever wanted to do is be like her sister. All she's wanted to do is ride her bike like her sister, run like her sister."
Rosie's parents said she now had more confidence.
An operation of this scale has never been attempted in Europe before. The only similar procedure took place 10 years ago in New Zealand.
Mr Guirish Solanki, one of the consultant neurosurgeons who operated on Rosie, said: "We are delighted with the results of this operation. "This is only the second time in the world that a surgical team has attempted to fix the thoracic spine to the hip side bones for a condition as rare as Rosie's.
"This case was very complicated as normally children with this condition do not have a working spinal cord or nerves but Rosie did. So in carrying out this procedure we had to be extremely careful not to damage her nerves."
Source: BBC News