Vertebral body tethering (VBT) has emerged as a motion-preserving surgical option for patients with idiopathic scoliosis. Since FDA approval in 2019, clinical experience has expanded rapidly, but several of VBT’s proposed advantages over posterior spinal fusion (PSF), including durable growth modulation, motion preservation, and disc preservation, remain incompletely proven. This state-of-the-art review, conducted by the Scoliosis Research Society Safety and Value Committee, critically evaluates the current evidence on VBT, with emphasis on patient selection, outcomes, and complications, distinguishing well-supported findings from claims that remain incompletely substantiated. Appropriate patient selection remains central to achieving successful outcomes. No literature consensus exists on optimal curve magnitude, though most published series enroll patients with major Cobb angles between 30° and 70°. Radiographic studies demonstrate that most of the correction occurs intraoperatively, with early postoperative alignment serving as an important predictor of long-term success. Many patients achieve meaningful deformity correction while preserving spinal motion. However, the durability of correction is less predictable than with PSF. Mechanical complications including tether breakage, loss of correction, and overcorrection are common and contribute to higher revision rates compared with fusion procedures. Complication and revision rates increase with longer follow-up, and mechanical, growth-related, and approach-related complications remain incompletely characterized beyond five years. VBT is a valuable option for carefully selected patients with idiopathic scoliosis, offering motion preservation and avoidance of fusion. However, several of its purported advantages over PSF remain incompletely proven, and outcomes are more variable and less predictable than fusion, particularly with longer follow-up. Comprehensive patient counseling, standardized outcome reporting, and continued prospective, longer-term investigation are needed to define VBT’s evidence-based role in scoliosis care.
Posterior spinal fusion (PSF) is the primary treatment for adolescent idiopathic scoliosis (AIS) curves >45°, yet planning remains largely radiographic and empirical, with limited integration of patient-specific biomechanics. AI and biomechanical modeling now offer opportunities for objective, personalized evaluation of instrumentation strategies. This study developed and evaluated a patient-specific model-based optimization framework combining AI-predicted instrumentation with deterministic physics-based biomechanical simulation to explore construct trade-offs within predefined computational constraints. Twenty AIS patients (Lenke 1/2, age 12–19) treated with selective thoracic PSF were analyzed using data from the MIMO clinical trial. Patient-specific digital twin models were generated from validated 3D reconstructions and implemented in a multibody dynamic simulation environment. AI-predicted instrumentation parameters (UIV, LIV, screw number, rod curvature) were varied within clinical ranges, generating 972 construct configurations per patient (19,440 total simulations). A multi-objective optimization algorithm identified AI-derived strategies balancing 3D correction, screw pullout forces, and preservation of unfused vertebrae, which were compared with simulated surgeon-performed constructs. Simulated outcomes included MT Cobb angle, thoracic kyphosis, apical vertebral rotation, screw pullout force, number of screws, and fused levels. Strategies were compared using repeated-measures MANOVA. Optimized configurations achieved similar modeled 3D correction to surgeon-performed constructs, with a mean 3° greater coronal correction (95
Respiratory complications remain a major cause of perioperative morbidity following paediatric neuromuscular scoliosis (NMS) surgery. Although respiratory optimisation strategies are widely used, their effectiveness remains uncertain. This systematic review evaluated respiratory optimisation strategies and postoperative pulmonary outcomes in children undergoing NMS correction. This systematic review followed PRISMA 2020 guidelines. PubMed/MEDLINE, Embase and CENTRAL were searched from inception to June 2026. Studies evaluating respiratory optimisation in paediatric NMS surgery were included. Two reviewers independently screened studies, extracted data and assessed methodological quality using Joanna Briggs Institute checklists. Certainty of evidence was assessed using GRADE. Findings were synthesised narratively owing to clinical and methodological heterogeneity. Ten observational studies involving 308 children were included. Interventions comprised non-invasive ventilation (NIV), mechanical insufflation-exsufflation, pulmonary rehabilitation, inspiratory muscle training, protocolised extubation and multidisciplinary perioperative pathways. NIV-based protocols reported successful early extubation and few respiratory complications, including amongst children with severe restrictive lung disease. Pulmonary rehabilitation and inspiratory muscle training were associated with improved pre-operative respiratory function, whilst multidisciplinary pathways reported favourable postoperative outcomes. Four studies had low and six had moderate methodological risk. However, the certainty of evidence was very low across principal respiratory outcomes, reflecting uncontrolled designs, heterogeneous interventions and imprecise comparative estimates. Structured respiratory optimisation appears feasible in children undergoing NMS correction, including those with substantial respiratory impairment. NIV and airway clearance are recurring components of reported pathways, but their comparative effectiveness remains uncertain. Prospective multicentre studies are needed to establish effective optimisation strategies and standardise perioperative respiratory care.
Selective posterior fusion for Lenke 5C adolescent idiopathic scoliosis (AIS) requires precise sagittal planning, as any mismatch within the instrumented segments may affect junctional levels and the adaptation of the adjacent unfused spine. Pre-bent patient-specific rods (PSR) with an associated pediatric predictive model represent an innovative solution to enhance surgical planning execution, yet to our knowledge no study has investigated their use in selective lumbar fusions. The aim was therefore to evaluate the reliability of PSR-based planning in predicting postoperative sagittal alignment of both fused and unfused segments in Lenke 5C AIS. Lenke 5C AIS patients underwent selective posterior fusion with PSRs between 2022 and 2024. Preoperative, planned, and postoperative radiographic parameters were collected at minimum 2-year follow-up. Predictive accuracy was assessed by calculating postoperative-to-plan differences (∆post–plan). Forty-eight patients were included (mean age 15.8 years; mean follow-up 2.8 years). Plan execution was excellent or acceptable in 96
Adult spinal deformity (ASD) surgery is a high-risk, high-cost domain in which preoperative planning plays a critical role in determining alignment goals, surgical strategy, and the balance between deformity correction and treatment-related complications, yet decisions still rely heavily on static radiographs, classification systems, and surgeon experience. In parallel, medical digital twins, continuously updated, patient-specific computational models that simulate alternative treatment paths, are emerging in other medical disciplines but have not been formally articulated for ASD. In this narrative review, we adapt the recently proposed five-component medical digital twin framework (patient, data connection, patient-in-silico, interface, and synchronization policy) to adult spinal deformity by mapping each component to ASD-specific data sources, computational models, clinical workflows, and validation pathways. We outline how existing tools in ASD, including classification systems, frailty and bone-health metrics, biomechanical modeling, motion analysis, mobile health data, and machine learning risk calculators, can serve as inputs to an ASD digital twin. We highlight priority use cases, such as choosing the magnitude of surgery, bone-health-aware planning, pelvic fixation and rod strategy, and selection among open, hybrid, and minimally invasive approaches, all reframed as comparative simulations with explicit uncertainty bands. Finally, we propose a staged roadmap, from minimal viable twins evaluated via retrospective replay, to shadow-mode deployment, to oversighted clinical pilots, while detailing challenges in data harmonization, model validity, governance, and equity. Rather than claiming that a mature ASD digital twin exists today, this work offers a practical blueprint for how digital twins could evolve into auditable, patient-specific decision-support tools that augment, rather than replace, surgeon judgment in spinal deformity surgery.
