CHICAGO (CBS) — A young woman who dedicates her life to helping others lost part of her hand in a tragic accident.

But a remarkable medical procedure that was pioneered here in Chicago took her from heartache to happiness.

Sarah Dean’s job as a nurse practitioner means the world to her, but a tragic accident halfway around the world changed her life forever.

It was 2016 when Dean was on a Christian medical mission in Bolivia setting up clinics for children when a sport-utility vehicle hit her bus – hard.

“My arm was pinned outside of the bus; under the bus,” Dean said. “Parts of my hand had to be removed. It was unsalvageable.”

Several surgeries later, Dean’s hand has no fingers – and other sections are also missing. But in the missing parts – even though they were no longer there – she could feel excruciating sensations rushing through them.

It’s called phantom limb pain.

“The best way I can describe it is that you take an ice pick to the back of your fingernails and you just continually jab at it, and then you would consistently light your hand on fire over and over again,” she said.

That’s because when Dean’s hand was amputated, the nerves were treated the traditional way – cut – and the ends were buried inside a muscle.

“She was crying; tearful,” said Dr. Gregroy A. Dumanian, of the Nortwestern University Feinberg School of Medicine. “She was showing me her limb.”

Dumanian co-developed a technique called Targeted Muscle Reinnervation, or TMR for short.

The way it works is that a surgeon takes the cut nerve, finds a nerve nearby, and hooks them up.

“So now instead of this live free wire, you’re connecting the circuit. The nerve re-innervates, or grows into that local muscle,” Dumanian said. “Heal a nerve as opposed to trying to hide a nerve – and that’s the big lesson.”

And that lesson has paid off for Dean – and more than 100 other amputees around the world.

“The latest tally – a hundred different surgeons have done TMR at 60 different medical centers,” Dumanian said. “So the whole field is just blossoming, mushrooming.”

Dean now says when her pain ended, her new life began.

“Since then, I met my husband. We got married three months ago, and we bought a house. And we have a puppy,” she said. “Life goes on. Life continues.”

Dean said she loves to stay active and spends a lot of time kayaking, biking and playing tennis with her husband.