1. Department of Orthopaedic Surgery, School of Medicine, University of Missouri-Columbia, Columbia, MO - USA
2. Department of Orthopaedics, University of Pennsylvania Medical Center, Silverstein Pavilion, Philadelphia, PA - USA
3. Department of Orthopaedic Surgery, University of California, San Francisco, CA - USA
4. Department of Materials Science and Engineering, University of Missouri-Rolla, Rolla, Missouri, MO - USA