Surgery turns cancer survivor's ankle into new knee joint

STONY BROOK, N.Y. -- A 13-year-old cancer survivor from New York is able to dance again despite having a left leg that faces backwards, thanks to a rare surgery that used her ankle to make a functioning knee joint.

In December of 2016, Delaney Unger was diagnosed with Osteosarcoma, a rare type of bone cancer, in her left distal femur. Then in April of 2017, the teen from Selden underwent the 13-hour rotationplasty surgery, also called Van Ness procedure, at Stony Brook Hospital.

"I just want to dance again," she said. "Because I've never done anything else in my life except dance."

That was the mandate she gave her doctors in April, and 17 months and one radical surgery later, her dream lives on.

The complex surgery removes the cancer by surgically amputating the diseased knee, then rotating the lower leg 180 degrees and attaching it to the remaining thigh. The foot faces backward, and the ankle acts as a new knee.

The primary reason for rotationplasty is to enhance the person's mobility as a prosthesis user. Placing the ankle joint in the position of the knee creates a functional, natural knee, and the toes provide important sensory feedback to the brain.

Unger said she wasn't as concerned about the cosmetic issues, since below-the-knee amputation instead of an above-the-knee amputation provides a tremendous difference in terms of function. A dedicated and versatile dancer, she decided to undergo the surgery in hopes of maintaining control and mobility in order to lead a full, active life.

"She actually has to retrain her body, retrain her muscles," said Dr. Fazel Khan, assistant professor of osteopathic surgery. "But when she moves her knee now, it's as if she was moving her old ankle. And this allows us to get rid of the cancer completely."

In October of 2017, she received a prosthesis that fits over the backwards foot and extends up the thigh. This allowed her to have motor power to walk, jump, dance and play. She danced in a recital in May 2018, performing lyrical, hip hop and jazz. Inspired by Stony Brook doctors, she has hopes of becoming a pediatric oncologist for her future career.

Dr. Khan said a traditional knee replacement would have prevented Delaney from ever dancing again. Now, that restriction is gone. But she's had to make a few adjustments.

"Usually if I can't do it the first time, I try it again and practice it home," she said. "And if I don't have it after a few weeks, then I'm like, OK, I can't really do that."

Her mom admits she was skeptical at first, but now she believes it was the correct decision.

"I was the last one to come on board with this decision," Melissa Unger said. "But when she turned to me in her hospital bed and said, 'I would rather have the chance to try something and fail then not be able to try it at all,' I knew this was the right choice."

Delaney will continue to see Stony Brook doctors for follow-up visits over the next five years.

"My daughter has an amazing outlook," Melissa Unger said. "She is very confident, doesn't hide it, and is comfortable and open about it...I also want to thank Stony Brook. The doctors have been there for her. We're very lucky to have outstanding care close to us. We didn't have to go to the city. Stony Brook has everything we need."