[Anatomical and radiological aspects in lumbopelvic fixation]

Spinal and pelvic surgery (as in neuromuscular scoliosis or unilateral highly unstable vertical sacral fractures or unstable H- or U-shaped sacral fractures) relies on lumbopelvic fixation. This technique belongs to the standard procedures for lumbosacral injuries in orthopedic surgery. Preoperatively, a CT scan with 1 mm slices is essential to detect anatomical variants and cortical narrow nesses. For optimal insertion of pedicel screws, knowledge of the pedicle diameter and length is necessary and screws should be placed convergent to each other taking into consideration the pedicle length and angle. For placement of the iliac screws exact knowledge of the anatomy is essential to avoid cortical wall perforation and neurovascular injuries. The safest screw path was determined as the bony canal between the posterior superior iliac spine (PSIS) and the anterior inferior iliac spine (AIIS). Intraoperatively, standard fluoroscopic views allow safe placement of the screws. The aim of the following manuscript is to illustrate anatomical and morphological aspects of the spine and pelvis as well as to describe important bony landmarks and optimal intraoperative C-arm views for optimal screw insertion.