SAN DIEGO -- Researchers in San Diego and the Midwest are trying to solve a medical mystery that is affecting mostly young people in their prime, including young military servicemen and women.

Quinn Donmeyer was pretty much like another student in her 20s. She was in college and very active, especially when it came to playing softball.

However, she eventually was told she needed arthroscopic surgery on her right shoulder.

But after the surgery, she hasn't been the same since.

"I recovered from the surgery and was feeling fine, but a short time later, all of a sudden the pain was back and it became progressively worse and worse," said Donmeyer.

She had no idea what was going on until she met Dr. Anthony Romeo, an orthopedic surgeon in Chicago who diagnosed her with joint chondrolysis.

The cartilage in Donmeyer's shoulder simply disappeared and eventually had to have a metal implant placed in her shoulder, but she wants answers.

"There appears to be a link with arthroscopic surgeries, but that's about all we can really say at this point," Romeo said.

Millions of arthroscopic surgeries are performed each year, but in the last 10 years, for some reason chondrolysis seems to be increasing.

Some 830 patients from around the world are being analyzed by Advance Health Solutions in La Jolla, but again, there is no conclusive proof as yet.

"We don't know if it's because of the surgery, during the surgery, something that happens after the surgery, we just don't know without more study," said Dr. Maryam Navaie, CEO of Advance Health Solutions.

"This is still a rare condition, more typically found in elderly patients whose cartilage simply wears out with age," Romeo said.

While rare, Romeo added, "The numbers of young people afflicted with this has grown over the last 10 years."

For information on Advance Health Solutions' research, click here.