| Affiliation: | 1. Department of Orthopaedics, University of California at San Diego, San Diego, USA;2. Department of Orthopaedics, Southern California Permanente Medical Group, San Diego, CA, USA;3. Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA;4. Department of Orthopaedics, Southern California Permanente Medical Group, Baldwin Park, CA, USA;5. Department of Orthopaedics, Southern California Permanente Medical Group, Anaheim, CA, USA;6. Department of Orthopaedics, Southern California Permanente Medical Group, Harbor City, CA, USA |
