1. Department of Orthopedic Surgery, University of Arizona, Tuscon, Arizona
2. Department of Orthopedic Surgery, Kaiser Permanente, Irvine, California
3. Department of Orthopedic Surgery, Kaiser Permanente, San Diego, California
4. Department of Surgical Outcomes and Analysis, Kaiser Permanente, San Diego, California
5. Department of Orthopedics, Southern California Permanente Medical Group, Orange County, Irvine, California