1. Shiley Center for Orthopaedic Research and Education, Scripps Clinic, La Jolla, California.
2. Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California.
3. Department of Radiology, School of Medicine, University of California–San Diego, San Diego, California.
4. Department of Mechanical and Aerospace Engineering, University of California–San Diego, La Jolla, California.