Bryan K Lawson1, Joel W Jenne1, Christopher J Koebbe2. 1. Department of Orthopaedics and Rehabilitation, Brooke Army Medical Center, 3551 Roger Brooke Drive, JBSA Fort Sam, Houston, TX 78234-6200, USA. 2. Department of Neurological Surgery, Brooke Army Medical Center, 3551 Roger Brooke Drive, JBSA Fort Sam, Houston, TX 78234-6200, USA.