I joined the registry. They sent me a questionnaire with a lot of specific questions about my physical abilities and my mental status. It was quick and easy to fill up. I am assuming they will use the registry to compare the impact of different treatments on quality of life.
So I checked it out, but can't register because they are not accepting people with SS in the thoracic cavity, which includes lungs. Doesn't seem right, but whatever.
This registry was set up by an orthopedic surgeon. He is most likely looking to improve his specialty. That's probably why thoracic patients are not interesting for him :-(
The Sarcoma Foundation of America also has a registry which is not filtering patients: