1. Division of Orthopaedic Surgery, Walter Reed Army Medical Center, Washington, D.C. 20307-5001 and Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799
2. Department of Clinical Investigation, Walter Reed Army Medical Center, Washington, D.C. 20307-5001
3. Department of Orthopaedics & Rehabilitation, University of Miami, Miami, Florida 33101-6960