1. Department of Orthopaedic Surgery, Wilford Hall Medical Center, Lackland Air Force Base, San Antonio. Texas.
2. Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts.
3. Institute of Biosciences and Bioengineering, Department of Chemical Engineering, Rice University, Houston, Texas.
4. Orthopaedic Biomechanics Laboratory, Beth Israel Hospital/Harvard Medical School, Boston, Massachusetts.
5. Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas.