1. Department of Bioengineering; University of California San Diego; La Jolla California 92093
2. Department of Orthopaedic Surgery; Washington University, St. Louis; Saint Louis Missouri 63110
3. Department of Orthopaedic Surgery; University of California San Diego; La Jolla California 92093
4. Department of Radiology; University of California San Diego; La Jolla California 92093