Ruth Smith, 13, was suffering from a rare condition called scoliosis which meant her back was permanently bent in an 'S' shape.

The condition was diagnosed five years ago and had caused her spine to grow as much as 78 degrees off straight.

And it even meant that one of her ribs was sticking out of her right side because her whole ribcage was twisted.

Normally with scoliosis, two titanium rods are screwed into the spine to help straighten it and brackets known as 'dominoes' are fixed in place to allow the rods to move.

But with young children this can cause long-term problems because fixing just two rods in place doesn't allow the spine to grow naturally.

Ruth's spinal surgeon, Evan Davies, felt that because of her age and the high level of flexibility needed for her gymnastics this would not work – so he invented his own.

Mr Davies, a consultant in spinal surgery at Southampton General Hospital, teamed up with a Swiss professor of engineering to design and manufacture the ground-breaking Davies' Dominoes.

And three months after the nine-hour operation, Ruth, from Portsmouth, was back on the vault – and is setting her sights on the 2012 European Championships.

Ruth's mum Miriam, 44, said the change in her daughter since the operation, which took place on June 3, has been amazing.

She said: 'We first spotted there was something wrong when she was eight and she has been monitored ever since then.

'Evan Davies got involved about two years ago when the curve in her spine began to get dramatically worse.

'She actually kept up her gymnastics right up until a week before the operation.

'But the pain had become too much for her and the curve in her spine was getting worse and worse.

If Ruth had been treated in the conventional way, she would have had to return to hospital each year for an operation. But because of Davies' Dominoes, which uses four rods, the only operation she will need in the future is when she stops growing.