1. Orthopaedic Research Laboratory, VA Medical Center, Creighton University Biomedical Engineering Research Center, Omaha, NE and Department of Orthopaedic Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, NE
2. VA Medical Center and Department of Orthopaedic Surgery, University of Florida, Gainesville, FL
3. Orthopaedic Research Laboratory, VA Medical Center, Omaha, NE and Department of Orthopaedic Surgery and Rehabilitation, University of Nebraska Medical Center, Omaha, NE
4. Orthopaedic Research Laboratory, VA Medical Center and Creighton University Biomedical Engineering Research Center, Omaha, NE