1. Hospital for Special Surgery, 535
East 70th Street, New York, NY
10021, USA.
2. Medstar Georgetown Orthopaedic Institute, 3800
Reservoir Road NW, Washington, DC 20007, USA.
3. Tria Orthopaedic Center, 8100
Northland Drive, Bloomington, MN
55431, USA.
4. University of Maryland School of Medicine, 2200
Kernan Drive, Baltimore, MD
21207, USA.