Minimally invasive techniques and enabling technologies for adult spinal deformity: state of the art and future...

Surgical management of adult spinal deformity (ASD) is complex, and traditional open surgery is associated with significant perioperative morbidity. These issues have catalyzed a paradigm shift toward enabling techniques and technologies designed to minimize iatrogenic injuries while achieving surgical goals. This comprehensive review synthesizes the current applications and future perspectives of these techniques and technological advancements. We examine the evolution of minimally invasive surgery (MIS), including the use of selection algorithms such as MISDEF-2 (minimally invasive spinal deformity surgery algorithm-2) and the "ceiling effect" of MIS correction. We discuss advanced techniques, such as anterior column realignment, which offers significant corrective power with less morbidity, and highlight evidence showing patient-reported outcomes comparable to those of open surgery. This review also analyzes the impact of robotic assistance and navigation, which provide quantifiable improvements in instrumentation accuracy (e.g., pedicle and S2-alar-iliac screws) and safety by reducing complications, such as facet joint violations. Furthermore, we explore the increased use of patient-specific implants, including pre-contoured patient-specific rods and three-dimensional printed interbody cages, which enhance the precise execution of preoperative plans. Finally, we discuss future directions, including the integration of these tools into efficient workflows, such as single-position surgery, and the emergence of augmented reality and predictive analytics. The synergistic integration of these technologies promises to establish safer, more precise, and personalized care for patients with ASD.