1. Department of Bioengineering, University of California–San Diego, La Jolla, California.
2. Department of Orthopaedic Surgery, University of California–San Diego, La Jolla, California.
3. Division of Orthopaedic Surgery, Scripps Clinic, La Jolla, California.
4. Institute of Engineering in Medicine, University of California–San Diego, La Jolla, California.