Variable posterior surgical techniques for atlantoaxial (C1-2) joint instability (AAI) have been introduced and advanced steadily during the past century. Many surgical techniques using wire or clamp were introduced before 1980s and these surgical approaches provided low biomechanical strength and low fusion rate. After then, screwbased techniques (trans-articular or segmental fixation) were introduced and popularized as an alternative or “gold standard” method. Screw-based methods have recently gained popularity and modified according to their targeted anatomical regions (pedicle, posterior arch, C1 lateral mass, pars inter-articularis and laminar). Each surgical technique has own strength and weaknesses, and their usefulness has been proved through many biomechanical analysis and clinical applications. Advantage and limitation of each surgical technique will be reviewed.
