The couple struggled with the dance steps. Ryan McWhirter needed to support his partner Cindy Shields as she twirled away from him and then curled back into his arms. But he kept grappling with it.

Abri Bentley woke up in a hospital bed on a chilly November day in 2017, halfway across the country from her home in Scottsdale. She had undergone surgery for a procedure that would terrify most ...