1. Surgical Outcomes and Analysis Department, Kaiser Permanente, San Diego, California
2. Department of Orthopaedic Surgery, Southern California Permanente Medical Group, Baldwin Park, California
3. Department of Orthopaedic Surgery, Southern California Permanente Medical Group, Irvine, California
4. Oslo Sports Trauma Research Center, Oslo, Norway
5. Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway
6. Department of Orthopaedic Surgery, Southern California Permanente Medical Group, San Diego, California