1. Brigham and Women’s Hospital and Harvard Medical School Boston Massachusetts
2. Weill Cornell Medicine, Hospital for Special Surgery New York New York
3. Boston University School of Medicine Boston Massachusetts
4. Boston University School of Medicine, Boston, Massachusetts, and Mercy Catholic Medical Center Darby Pennsylvania
5. Cleveland Clinic Cleveland Ohio
6. Mayo Clinic Rochester Minnesota
7. Massachusetts General Hospital Boston
8. Washington University School of Medicine St. Louis Missouri