“…Previous studies evaluating thoracic placement have focused mostly in the lower thoracic region [1,4,12,16,17,19,26,29]. Furthermore, accuracy of thoracic pedicle screw instrumentation has been reported in several cadaveric populations [5,7,21,22,25,28,29,31,32], and with the use of assisted-navigation techniques [2,5,6,8,25]. While there is data on thoracic screw placement accuracy in the literature, we found little information specifically reporting on upper thoracic screws inserted in vivo on nondeformed spines.…”