Murat Şakir Ekşi1, Rasim Babayev2. 1. Department of Orthopedic Surgery-Spine Center, University of California at San Francisco, 500 Parnassus Avenue MU320 West, San Francisco, CA, 94143-0728, USA. muratsakireksi@gmail.com. 2. Department of Neurosurgery, National Center of Oncology, Baku, Azerbaijan.