1. VA Puget Sound Health Care System; University of Washington; Seattle; WA; USA
2. VU University Medical Centre; Amsterdam; The Netherlands
3. Nuffield Orthopaedic Centre; Oxford; UK
4. Gustave Dron Hospital; Tourcoing; France
5. IWGDF; Heemstede; The Netherlands
6. University of Manitoba; Winnipeg; MB; Canada
7. University of Texas Southwestern Medical Center and Parkland Hospital; Dallas; TX; USA