Princess Eugenie's Walk Down the Aisle Was a 'Seismic Moment' After Scoliosis Surgery at Age 12

Princess Eugenie made the bold decision to show off the scar that helped her stand tall on her royal wedding day.

Her stunning bridal gown, which featured a fitted bodice and full pleated skirt, was designed by Peter Pilotto and Christopher De Vos, who founded the British-based label Peter Pilotto, in London in 2007. The dress features a neckline that folds around the shoulders to a low back that drapes into a flowing full-length train. The low back feature on the dress was at the request of Eugenie, who had surgery at 12 years old to correct her scoliosis.

“It’s important,” a source at the wedding tells PEOPLE of the princess bride’s decision not to cover up the mark. “If she hadn’t had that operation, she wouldn’t be able to walk — and here she was, walking down the aisle, so it was a seismic moment.”

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Eugenie’s mother, Sarah Ferguson, Duchess of York, previously told the Evening Standard that spinal surgeon Jan Lehovsky is one of a number of Royal National Orthopaedic Hospital staff who were invited to the nuptials.

In a June Instagram post, Eugenie opened up about her scoliosis diagnosis as a child. She posted a photo of her X-rays, which show the 8-inch rods doctors inserted into her spine and the 1.5-inch screws at the top of her neck after an 8-hour operation she endured.

“Today is International Scoliosis Awareness Day and I’m very proud to share my X Rays for the very first time,” she wrote in the caption. “I also want to honour the incredible staff at The Royal National Orthopaedic Hospital who work tirelessly to save lives and make people better. They made me better and I am delighted to be their patron of the Redevelopment Appeal.”

Eugenie has been a patron of the Redevelopment Appeal, a fundraising campaign for newer facilities and equipment for RNOH, since 2012.

“Without the care I received at the RNOH I wouldn’t look the way I do now; my back would be hunched over,” she said. “And I wouldn’t be able to talk about scoliosis the way I now do, and help other children who come to me with the same problem. My back problems were a huge part of my life, as they would be for any 12-year-old. Children can look at me now and know that the operation works.”