Evolving Concepts in Adult Spinal Deformity Surgery.

Adult spinal deformity is a multifaceted condition increasingly encountered in aging populations, often complicated by coexisting hip and knee osteoarthritis. It is important to present an integrated review of biomechanical, surgical, and technologic advances shaping modern adult spinal deformity management. First, the hip-spine-lower extremity relationship and how lower limb pathology impairs compensatory mechanisms, alters spinopelvic alignment, and influences surgical outcomes should be examined. Next, the evolution of classification systems and alignment philosophies-ranging from the Scoliosis Research Society-Schwab classification to patient-specific, age-adjusted models-should be outlined alongside technologic innovations such as artificial intelligence, three-dimensional planning, and robotics. The role of minimally invasive surgery is rising, and its benefits, limitations, and patient selection criteria should be evaluated. Critical topics include frailty-adjusted surgical planning, prevention of proximal junctional kyphosis or failure, and multidisciplinary strategies to improve functional outcomes and reduce complications. Collectively, there is a paradigm shift toward personalized, precision-driven care in adult spinal deformity surgery.