Alfred J Pisano1, Scott C Wagner2, Melvin D Helgeson2, Jefferson W Jex2. 1. Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, MD 20889, USA. 2. Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, MD 20889, USA; Division of Orthopaedics, Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD 20889, USA.