Background and Objectives: Enhanced Recovery After Surgery (ERAS) pathways are increasingly used in spine surgery, but uptake in adolescent idiopathic scoliosis (AIS) remains heterogeneous across institutions. Evidence in pediatric deformity surgery supports shorter recovery with protocolized care, yet real-world comparative data combining ERAS and the erector spinae plane block (ESPB) remain limited. This study aimed to compare early postoperative outcomes between a historical standard-care pathway and a structured ERAS+ESPB pathway in adolescents undergoing posterior spinal fusion for AIS. Materials and Methods: A single-center retrospective time-based comparative cohort study design included consecutive AIS patients (<18 years) treated between 1 January 2024 and 31 December 2025. The standard-care pathway was applied to patients operated on before 1 June 2025 (n = 34), whereas the ERAS+ESPB pathway was applied to those operated on from 1 June 2025 onward (n = 35), following formal institutional implementation. Outcomes included postoperative pain assessed using the visual analog scale under two functional conditions—at rest in the supine position and during standing/mobilization—at POD0, POD1, POD2, POD3, discharge, and 2-week follow-up; postoperative nausea at POD0–POD3; and length of stay (LOS). Between-group pain comparisons used Welch’s t-test; nausea used Fisher’s exact test; LOS used the Wilcoxon rank-sum test. Results: At POD0, supine pain was lower in ERAS+ESPB (1.50 ± 0.55) than in standard care (3.20 ± 1.50; p < 0.001). From POD1 onward, supine pain did not differ significantly between groups. Among assessable patients, standing pain was lower in ERAS+ESPB at POD2 (3.05 ± 1.53 vs. 4.50 ± 1.05; p = 0.020), POD3 (2.82 ± 1.62 vs. 4.17 ± 1.03; p = 0.006), and 2-week follow-up (1.45 ± 0.80 vs. 2.26 ± 0.93; p = 0.006). Nausea was lower in ERAS+ESPB at POD0 (11.4% vs. 35.3%; p = 0.024) and POD2 (8.6% vs. 32.4%; p = 0.018), with no significant differences at POD1 or POD3. LOS was shorter in ERAS+ESPB (5.41 ± 1.10 vs. 8.32 ± 2.06 nights; p < 0.001). Conclusions: In adolescents undergoing posterior spinal fusion for AIS, an ERAS-based perioperative pathway incorporating ESPB was associated with improved early postoperative recovery, particularly in terms of immediate postoperative pain, pain during mobilization, early postoperative nausea at selected time points, and length of hospital stay. Prospective multicenter studies are needed to confirm these findings and clarify the independent contribution of individual pathway components.

Background and Objectives: Postoperative pain after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) shows substantial interindividual variability, particularly during early mobilization. Although preoperative psychological vulnerability has been associated with less favorable pain trajectories in prior AIS research, evidence focused on the acute postoperative phase remains limited. This preliminary study evaluated whether preoperative psychological factors are associated with acute postoperative pain intensity, with separate assessment of resting and standing pain. Materials and Methods: A single-center retrospective cohort study included consecutive adolescents with AIS (<18 years) who underwent primary elective posterior instrumented spinal fusion between 1 January 2024 and 31 December 2025. Preoperative psychological variables were collected using validated instruments (STAIC-State, STAIC-Trait, Pain Catastrophizing Scale, HAQ/FDI, and inverted SRS-22). Pain intensity (VAS 0–10) was recorded at postoperative day (POD) 1, POD2, POD3, discharge, and 2-week follow-up in supine and standing positions. Derived endpoints included peak in-hospital standing pain, in-hospital standing pain burden (AUC), and standing–rest pain gaps. The prespecified inferential analysis used a linear mixed-effects model with fixed effects for time, position, preoperative STAIC-State, and position × STAIC-State interaction, with a patient-level random intercept. Results: Thirty-five patients were analyzed (mean age 15.2 ± 3.4 years; 62.9% female), with complete pain data at all timepoints. During hospitalization, standing pain was descriptively higher than resting pain (largest mean difference at POD2: 0.73 VAS points), with convergence at week 2 (both 1.52). In mixed-model analysis, pain significantly decreased at week 2 versus POD1 (β = −1.261, 95% CI −1.853 to −0.669; p < 0.001). Preoperative STAIC-State was not independently associated with postoperative pain (β = 0.030, 95% CI −0.065 to 0.124; p = 0.545), and no significant position × STAIC-State interaction was found (β = −0.008, 95% CI −0.079 to 0.064; p = 0.836). Conclusions: In this retrospective preliminary AIS cohort, postoperative pain improved significantly over time, while movement-evoked pain remained relevant during early recovery. In this preliminary cohort, no clear association was detected between preoperative state anxiety and acute postoperative pain intensity, supporting the need for broader multidimensional prognostic models in future prospective multicenter studies.