AFIS-CL technique: A posterior reduction method enabling three-dimensional control in vertically unstable pelvic ring injuries.

Abstract

Achieving accurate reduction of a displaced hemipelvis in vertically unstable posterior pelvic ring injuries remains technically challenging. We describe a reproducible posterior reduction technique, termed the Anchored-Free Inter-Screw with Cobb Leverage (AFIS-CL) technique, which utilizes an anchored reference screw, a plate-independent free screw, controlled compression with a Jungbluth clamp, and adjunctive leverage using a Cobb's elevator. Reduction is performed through a posterior approach without skeletal traction, allowing direct intraoperative control of hemipelvic alignment. Sequential correction of vertical, anteroposterior, and rotational displacement is achieved under fluoroscopic guidance, followed by definitive posterior fixation while maintaining the achieved reduction. The technique was applied in five patients with vertically unstable posterior pelvic ring injuries. Satisfactory radiographic reduction was achieved and maintained in all cases without neurovascular complications, and no secondary displacement was observed at final follow-up. The AFIS-CL technique provides a practical and reproducible posterior reduction strategy that may facilitate three-dimensional correction and stable maintenance of reduction in vertically unstable pelvic ring injuries.