BBC South health correspondent
A teenage gymnast from Portsmouth has become the first person in the world to get a new kind of implant to help straighten her back.
Ruth Smith has scoliosis of the spine - which means her back is severely bent. But a device invented by a surgeon in Southampton has helped put it right.
Ruth, who is 13 and trains with Portsmouth School of Gymnastics, was diagnosed with scoliosis five years ago.
"The curve in Ruth's back was very pronounced," said her mother, Miriam.
"It got to the point where it was 78 degrees out of kilter with what a straight spine should be. We really couldn't have left it much longer."
Normally with scoliosis, two titanium rods are screwed into the spine, which helps straighten it.
But with young children this can cause problems because it does not allow the spine to grow. Further painful operations are then needed.
Sometimes surgeons use what are called "dominoes" - brackets which allow the rods to slide, giving greater flexibility.
But Ruth's spinal surgeon, Evan Davies, felt that because of her age and the high level of flexibility needed for her gymnastics - these would not do.
So he invented his own.
Mr Davies teamed up with a Swiss professor of engineering to design and manufacture the "Davies Dominoes" - which he used in Ruth's back.
Since then 10 other people have had them fitted and he is monitoring the results.
"These dominoes allow us to put in four rods instead of the usual two," said Mr Davies, who is based at Southampton General Hospital.
"As Ruth grows, the rods will spread apart - allowing the growth of the spine to occur but still controlling the shape of it.
"Traditionally, we used to do this with a lot of wires and boxes which meant having to go back to surgery every six months. Ruth will probably only need one more operation, when she has stopped growing."
The operation to fix Ruth's spine took nine hours.
She said: "I was a bit nervous but I knew it would work out because I was in safe hands."
And within three months she was back training in the gym.
"When I first went back after the operation I was only going for half an hour. I kept building that up and it felt OK.
"I was a bit worried about the back at first, but I can do all the things I used to do, so I feel fine," she added.
Ruth competes in Team Gym - three disciplines which involve floor dance, tumbling (back-flips and somersaults) and a kind of vault. Her team compete at international level and are hoping to travel to Texas for a competition next year.
Her coach, Julian Such, said: "When I heard what they had done to her with the bars and bits and pieces through her back I thought how on earth is she going to be able to bend for back flips and things like that?
"But she can. I don't know what they've done, but it works - and it's amazing."