A mother who thought her 10-year-old was suffering from growing pains has told of her shock when an X-ray revealed the schoolgirl's spine was so badly twisted it formed the letter 'S'.
In early 2015, Mackenzie Shoob began complaining to her mother Karen, 42, that her back was aching.
At first, Karen and her husband Andrew, also 42, of Borehamwood in Hertfordshire thought it must be growing pains.
But when the pain became so agonising that Mackenzie could barely walk, her worried parents sought help from a doctor, who diagnosed her with scoliosis – an abnormal curvature of the spine.
"I thought it would be a straight-forward appointment, and that we'd be told Mackenzie just needed some physiotherapy," said Karen. "I had no idea our lives were about to change.
"The doctors examined Mackenzie and told me to come and take a look. I couldn't believe what I was seeing. Her whole body curved to the left.
"He asked her to bend down and touch her toes, and when she did her shoulder blade popped out on one side.
"He then asked to speak to me in private and said, 'We're referring you to the Royal Orthopaedic Hospital, where they have some of the best surgeons in the world. Do you understand what I'm saying?' And I said, 'yes, you mean my child needs an operation'.
"When I got home, I burst into tears. I felt like the worst mum in the world for not spotting it sooner."
Though Karen said Mackenzie had been complaining about back ache for a few months, outwardly the curving to her spine was not visible.
"We'd been on a summer holiday to America just a few weeks earlier. Mackenzie had been on the beach in swimwear and looked absolutely fine," she recalled.
"She must have been in so much pain, but she kept a brave face.
"We've since learned that it's very subtle initially. Children with it just slightly curve to the side, so you wouldn't necessarily spot it.
"It seemed to get severe really suddenly when Mackenzie went back to school. I remember being in Tesco once doing the shopping and she was literally hanging off the trolley because she didn't want to walk.
"She started complaining that PE was hurting her, so we booked the doctors and stopped her doing exercise until we knew what was wrong."
Following the diagnosis, the family were referred to the Royal Orthopaedic Hospital in Stanmore, Middlesex.
However, after being told they could face a four month wait for an initial appointment, Karen and Andrew took Mackenzie for a private X-Ray.
There, it was discovered that her spine had twisted 61 degrees and was virtually s-shaped.
"We were told 61 degrees is very severe for a child of Mackenzie's age," Karen recalled. "If she had another growth spurt, the curvature could get even worse, so we needed to operate as soon as possible."
Faced with a frantic race against time, Karen took to the internet to explore her options.
According to the NHS, the main treatment options currently available for children of Mackenzie's age are either a back brace or surgery, which involves inserting growing rods with the aim of controlling the growth of the spine, while partially correcting the scoliosis.
If Mackenzie was to go down this route, she would need to return to a specialist every four to six months to have the rods lengthened in accordance with her growth.
Then, when she stopped growing, she would need to undergo spinal fusion surgery, which sees the spine straightened via metal rods attached with screws, hooks and/or wires.
Bone grafts are also used to fuse the spine in place, and the metalwork is usually left in place permanently.
"It seemed like so much surgery to put her through, and the recovery times would see her miss a lot of school," said Karen.
"Plus, I've spoken to kids who've had it and they've said they can feel the rods in their backs.
"I started searching through scoliosis support groups a lots of people mentioned a surgery they have in the US called vertebral body tethering.
"I spoke to a mum from the UK whose child had had it, and she said it was amazing."
Vertebral body tethering (VBT) works by placing screws into the convex side of the vertebrae - where growth is faster - and connecting them with a tether cord which, when tightened, will hopefully straighten the spine.
As there are no rods involved, budding gymnast Mackenzie would have almost full flexibility following the operation.
"Only four children in the UK have had VBT so far that we know of – we'd be number five," said Karen.
"The surgery is virtually keyhole. They go in through a tiny incision and deflate one lung so they can reach the spine.
"At the moment, I'm working on getting her lungs as strong as possible to prepare for this. We do Pilates every morning."
After flying to the States and meeting with three world-renowned surgeons who offer the operation, the family were told that Mackenzie could undergo the procedure at Shriners Children's Hospital in Philadelphia on February 24.
To thank the "amazing" hospital for transforming their daughter's life, Karen and Andrew have set up a GoFundMe page. They are hoping to raise £10,000 to donate as a token of their gratitude.
"It's a chance to make Mackenzie better and take away her pain. To be able to give that to my child is amazing," said Karen.
"It's my chance to give back as a mum."
To help the family fundraise, visit www.gofundme.com/macksjourney.