The S2-Alar-Iliac Screw for Pelvic Trauma

Percutaneous sacro-iliac screw osteosynthesis is considered to be standard of care for most posterior pelvic ring fractures. However, special situations require alternative strategies for sufficient stabilization. In these cases, stabilization can often be achieved using posterior instrumentation e.g. using SIPS-screws (spina-iliaca-posterior-superior screws). However, this often leads to implant-related aggravation of the sometimes already critical soft tissue conditions after pelvic trauma. S2-Ala-Ilium screws (S2AI screws) are a suitable alternative. The starting point lies medial of the posterior superior iliac spine below the iliac level. It is almost in line with a potential spinal instrumentation and therefore usually causes fewer soft tissue problems. Although this technique has been widely used in spinal surgery in recent years, its use in orthopaedic traumatology is largely unknown. The possibilities but also the limitations of this technique for the treatment of injuries to the pelvis are illustrated by this retrospective case series.