[1] Walter Reed Natl Mil Med Ctr, Dept Anesthesiol, Bethesda, MD 20814 USA
[2] Walter Reed Natl Mil Med Ctr, Dept Surg, Div Orthopaed, Bethesda, MD USA
[3] Uniformed Serv Univ Hlth Sci, Def & Vet Ctr Integrat Pain Management, Dept Mil & Emergency Med, Bethesda, MD 20814 USA
[4] Henry M Jackson Fdn Adv Mil Med, Rockville, MD USA