Decision-Making in Complex Lumbar Disorders

Adult spinal deformity (ASD) and complex lumbar degenerative conditions represent a major and active challenge in modern spine surgery, owing to the aging global population with higher expectations in terms of mobility and function. Traditionally, surgical planning has relied on clearly defined ranges based on standardized metrics; however, decision-making pathways have shifted toward individualized, segmental alignment goals that prioritize both Health-Related Quality of Life (HRQoL) and the prevention of mechanical complications even if it means to under-correct the deformity with respect to the traditionally defined ranges. This chapter explores a multifaceted decision-making framework, integrating patient-reported measures (PROMs) with advanced diagnostic tools such as 3D gait analysis and AI-driven spinopelvic measurement systems like SpinePose. For ASD, the application of age-adjusted alignment targets and the Global Alignment and Proportion (GAP) score is reviewed as an essential strategy to prevent overcorrection and proximal junctional failure (PJF). In cases of degenerative spondylolisthesis, we have described the clinical dilemma between decompression alone and decompression with fusion, focusing on protocols that identify instability through facet joint effusion and facet angles. We have reviewed surgical techniques for deformity correction ranging from minimally invasive lateral approaches to posterior multilevel crack osteotomies (PMCO) for rigid revision cases. Finally, this chapter details multidisciplinary enhanced recovery after surgery (ERAS) protocols and complication-prevention strategies involving sub-laminar tethers and cement augmentation to minimize the burden of revision surgery.