Adult spinal deformity (ASD) alters sagittal alignment and trunk centre of mass location, increasing spinal loading. Current clinical assessment of ASD primarily focuses on alignment parameters disregarding patient’s body shape variability. This study aimed to evaluate the relative effects of spinal sagittal alignment and body mass distribution (i.e., body shape) on spinal loads and trunk centre of mass location in upright-posture and forward flexion. Sagittal alignments of 754 patients with ASD were obtained from clinical data. Trunk mass distributions were assessed in adult male volunteers (10 healthy weight, 9 obese). Using an established musculoskeletal model of the spine, inverse dynamics simulations were performed for each combination of sagittal alignment and trunk mass distribution profile. A factorial analysis using generalised linear models elucidated the relative effects of alignment vs. body shape. Sagittal alignment primarily determined the antero-posterior positioning of trunk centre of mass; body shape, its cranio-caudal location. In the healthy weight cohort, the relative effect of mass distribution on compressive loads was 14–98

Background:Surgical strategies for recurrent lumbar disc herniation (ReLDH) range from repeat microdiscectomy (MD) to instrumented fusion (IF). Identifying predictive factors for surgical treatment could improve patient selection and outcomes. The primary objective of this study was to investigate the impact of Modic changes (MC) on clinical outcomes, radiological progression, and re-operation rates in ReLDH. The secondary objective was to compare outcomes between MD and IF stratified by MC patterns to determine whether MC assessment can guide surgical decision-making. Methods:This is a pre-planned subgroup analysis from a single-center retrospective cohort study of prospectively collected registry data. We analyzed 450 consecutive patients who underwent surgery for ReLDH (MD: n = 316, IF: n = 134) from 2004 to 2024. Radiological assessment included T1-and T2-weighted magnetic resonance imaging (MRI) sequences analyzing presence and type of MC, disc height, and Pfirrmann grade of the affected segment, and spinopelvic parameters on standing radiographs. Persistent MC were defined as maintaining the same Modic type at both index and revision surgery (e.g., Type 1→Type 1). Patient-reported outcome was assessed using the Core Outcome Measures Index (COMI) and achievement of Minimal Clinical Important Change (MCIC ≥2.2 points) up to 5 years postoperatively. Re-operation rates, time to re-operation, and rates of subsequent re-revision surgery were analyzed for both surgical groups, with at least 5 years of follow-up. Results:Patients with persistent MC Type 1 (n = 64; MD: 41, IF:23) demonstrated the shortest median time to revision (0.58 years) compared to no MC (1.03 years, p = 0.012). Persistent MC Type 1 demonstrated the highest re-revision rate among all MC patterns following MD (48.8%), which was dramatically reduced with IF (13.0%, p < 0.05), representing a 3.7-fold risk reduction. Overall re-revision rates were 36.7% for MD versus 15.7% for IF (p < 0.001). Persistent MC Type 1 pattern showed accelerated disc degeneration with progression to Pfirrmann grade 5 in 29.7% (vs 5.8% in no MC, p < 0.001) and severe disc height loss (>30% height loss) in 20.3%. While COMI outcomes showed no significant differences between surgical approaches at any timepoint, IF demonstrated numerically greater improvement at 2 years (5.3 vs 3.5 points, p = 0.692; derived ODI: 33.1 vs. 25.9). MCIC achievement in persistent MC Type 1 patients showed no significant differences at any time point: 3 months (65.0% IF vs 47.8% MD), 1 year (63.2% IF vs 64.7% MD), 2 years (76.9% IF vs 70.6% MD), and 5 years (66.7% IF vs 66.7% MD). Conclusion:Persistent Type 1 MC represent a distinct high-risk phenotype in ReLDH characterized by early recurrence, elevated re-revision rates, and accelerated segmental degeneration, compared to other MC types. The 3.7-fold reduction in re-revision rates and superior functional outcomes with IF provide compelling evidence, that warrant consideration in surgical decision-making.

Surgical treatment for Scheuermann's Kyphosis (SK) in adolescents is well-established, but its role in adults remains controversial. This study challenges the traditional non-operative stance by evaluating the clinical outcomes of surgery in adult SK patients, using a matched cohort of adult idiopathic scoliosis (Adult IS) patients as a clinical benchmark. A retrospective, 1:3 matched-cohort study from a multicenter database with a minimum 2-year follow-up. Thirty-three SK patients were matched with 99 Adult IS patients by age and number of instrumented levels. Demographics, radiographic parameters, surgical data, complications, and patient-reported outcome measures (PROMs) were analyzed. 33 SK patients and 99 patients from the Adult IS comparative cohort were included. Mean age was 32.1 years; 82.8

Pedicle subtraction osteotomies (PSOs) are well-established for rigid sagittal deformities, but the efficacy and safety of biplanar PSOs (BiPSOs) remain uncertain. This study aims to evaluate whether BiPSOs compromise sagittal correction or elevate surgical morbidity or complication rates. A retrospective analysis of a prospective multicentric adult spinal deformity database included patients who underwent a single Schwab-3/4 PSO with at least two years of follow-up. BiPSOs were defined by segmental angular changes (SAD) greater than 5° in both the sagittal and coronal planes, while uniplanar (UPSOs) had SAD greater than 5° in one plane. Demographic, surgical, and outcome variables were compared. The study included 33 BiPSOs and 123 UPSOs. No differences were found for baseline demographic characteristics. UPSOs were more common in patients with prior spinal surgery (57.6

Background: Optimal surgical treatment for recurrence of lumbar disc herniation (LDH) remains controversial, with options ranging from repeat microdiscectomy (MD) to instrumented fusion (IF). This study aimed to guide surgical decision-making by analyzing reoperation rates, clinical and radiographic risk factors for treatment failure, and functional outcomes following MD versus IF. Methods: Prospectively collected data from 450 patients in our outcomes database who underwent surgery for recurrent LDH from 2004 through 2023 were retrospectively analyzed. Clinical assessment included predominant symptoms, neurological deficits, and American Society of Anesthesiologists (ASA) grade. Radiographic assessment included disc height, Pfirrmann grade, facet angle, and Modic changes on magnetic resonance imaging, as well as spinopelvic parameters on standing radiographs. Patient-reported outcomes were assessed using the Core Outcome Measures Index (COMI) and achievement of the minimal clinically important change (MCIC) of ≥2.2 points. Propensity-score matching (PSM) was performed to control for confounding factors. Reoperation rates were analyzed with a minimum 5-year follow-up. Results: Of 450 patients with recurrent LDH, 316 (70.2%) underwent MD and 134 (29.8%) underwent IF. In 192 patients after PSM, IF showed nonsignificantly higher MCIC achievement (odds ratio [OR] = 1.20, 95% confidence interval [CI]: 0.66 to 2.17, p = 0.65) and lower COMI scores compared with the MD group (3.34 ± 2.89 versus 4.01 ± 2.95, p = 0.059; derived Oswestry Disability Index [ODI]: 23.8 versus 28.1). IF demonstrated significantly lower reoperation risk compared with MD (15.7% [116/316] versus 36.7% [21/34], p < 0.001). The reoperations following MD were predominantly subsequent IF (73.3%) and repeat MD (23.3%), while the reoperations after IF were predominantly adjacent segment surgery (57.1%) and hardware revision (33.3%). BMI of ≥35 kg/m 2 was a significant predictor of reoperation after MD (univariate OR = 3.63, p = 0.039), while disc height of <6 mm (OR = 1.97) and Modic type-1 changes (OR = 1.78) showed trends toward increased reoperation risk (both p < 0.10). Conclusions: Although both procedures achieved clinical improvement, IF demonstrated superior long-term durability as shown by significantly lower reoperation rates over extended follow-up. Our findings support a risk-stratified surgical selection: IF should be strongly considered in patients with BMI of ≥35 kg/m 2 and those with progressive disc degeneration, whereas MD remains appropriate for patients without these risk factors. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

STUDY DESIGN:Retrospective register study. OBJECTIVE:Determine when preoperative quality of life (QoL) declines in adult thoracolumbar/lumbar adolescent idiopathic scoliosis (TL/L-AIS) patients, analyze postoperative age-related changes, and assess the influence of preoperative sagittal alignment and the lowest instrumented vertebra (LIV) on QoL. SUMMARY OF BACKGROUND DATA:The effect of surgery on self-image, function, and pain may vary depending on age, alignment, and fusion length. MATERIALS AND METHODS:A total of 310 patients were analyzed preoperatively and postoperatively until two-year follow-up. Scoliosis Research Society-22 (SRS-22) and Short Form-36 (SF-36) scores were collected. Relative spinopelvic alignment (RSA), T4 and L1 pelvic angles (T4PA-L1PA), and LIV were determined on radiographs. Linear mixed-effect regression models were used, including group, time, and interaction. RESULTS:The phase 30 to 42 years represented an inflexion point in preoperative SRS-22 total scores, after which scores were unlikely to reach postoperative levels of younger patients. All age groups improved postoperatively. The SRS-22 total score difference at two years was -0.48 between the 40 and 60-year groups and younger-than-40-year groups ( P <0.001), -0.50 between older-than-60 and younger-than-40-year groups ( P <0.001). Self-image improved in all groups: +1.16 in those younger than 40 years, +1.08 in those aged 40 to 60 years, and +1.14 in those older than 60 years. Pain improved in patients aged 40 to 60 years, +0.75, and older than 60 years, +1.07. The SF-36 Physical Component Summary improvement was larger in patients aged 40 to 60 years, +6.76 (P<0.001), and older than 60 years, +8.74 (P<0.001), versus those younger than 40 years. Preoperatively, severely malaligned patients had the lowest SRS-22 and the largest postoperative improvement. Patients with LIV S1/iliac had lower SRS-22 than those with LIV L2/L3 or L4/L5 at two-year follow-up. CONCLUSION:In adult TL/L-AIS patients, QoL declined around the fourth life decade; postoperative recovery patterns differed. All age groups improved QoL postoperatively. Self-image improved the most. Pain and the physical component improved most in patients older than 40 years. Preoperative sagittal malalignment and the LIV influenced QoL.

To identify postoperative radiographic parameters independently associated with clinically meaningful pain improvement one year after surgery in a selected cohort of adolescents with idiopathic scoliosis (AIS) reporting substantial preoperative pain. This was a retrospective analysis of a prospectively collected multicenter database including 378 AIS patients treated with posterior spinal fusion. Patients with substantial preoperative pain (SRS-22 pain ≤ 4.0) and ≥ 1-year follow-up were included. A 0.6-point MCID in SRS-22 pain defined meaningful improvement. Groups were compared and significant postoperative radiographic variables plus preoperative pain entered a multivariate logistic regression model. Nagelkerke R² and ROC-AUC assessed performance. Eighty-eight patients met the inclusion criteria (mean age 14.7 ± 1.8 years; 77 females). Sixty-four patients (72.7

Introduction:Proximal junctional kyphosis/failure (PJK/PJF) remains a frequent and severe complication following adult spinal deformity (ASD) surgery. While alignment risk factors are known, the specific mechanical influence of anterior malalignment and pelvic retroversion across different fusion levels remains poorly understood. Research question:How do postoperative anterior malalignment and pelvic retroversion influence PJK/PJF risk and biomechanical forces at the proximal junction based on upper instrumented vertebra (UIV) selection? Material and methods:We retrospectively analyzed 351 ASD patients fused to the pelvis, stratified by UIV: lower thoracic (LT, T9-T11; n = 206) or upper lumbar (UL, T12-L2; n = 145). Radiographic spinopelvic alignment was evaluated. Additionally, a validated finite element model (FEM) of T10-pelvis and L2-pelvis constructs simulated progressive anterior offsets and pelvic retroversion to quantify UIV endplate compressive and shear forces. Results:PJK/PJF incidence was comparable between groups (LT: 22.4%, UL: 22.2%). In both cohorts, PJK patients exhibited greater 6-week postoperative global sagittal malalignment and pelvic retroversion. LT failures were driven by higher SVA and thoracic kyphosis, whereas UL failures associated with increased segmental T10-L2 kyphosis. FEM showed LT constructs experienced predominant compressive forces scaling with anterior offset, while UL constructs experienced predominant posterior shear forces. Pelvic retroversion offered negligible mitigation against compression and limited shear reduction. Discussion and conclusion:UIV selection dictates the biomechanical failure mechanism, not the overall PJK/PJF risk. LT instrumentation exposes the proximal junction to compression, whereas the UL spine is susceptible to shear-driven failure. Pelvic retroversion cannot compensate for residual anterior malalignment. Therefore, UIV choice must account for regional alignment and predictable force vectors.

BACKGROUND:Optimal surgical treatment for recurrence of lumbar disc herniation (LDH) remains controversial, with options ranging from repeat microdiscectomy (MD) to instrumented fusion (IF). This study aimed to guide surgical decision-making by analyzing reoperation rates, clinical and radiographic risk factors for treatment failure, and functional outcomes following MD versus IF. METHODS:Prospectively collected data from 450 patients in our outcomes database who underwent surgery for recurrent LDH from 2004 through 2023 were retrospectively analyzed. Clinical assessment included predominant symptoms, neurological deficits, and American Society of Anesthesiologists (ASA) grade. Radiographic assessment included disc height, Pfirrmann grade, facet angle, and Modic changes on magnetic resonance imaging, as well as spinopelvic parameters on standing radiographs. Patient-reported outcomes were assessed using the Core Outcome Measures Index (COMI) and achievement of the minimal clinically important change (MCIC) of ≥2.2 points. Propensity-score matching (PSM) was performed to control for confounding factors. Reoperation rates were analyzed with a minimum 5-year follow-up. RESULTS:Of 450 patients with recurrent LDH, 316 (70.2%) underwent MD and 134 (29.8%) underwent IF. In 192 patients after PSM, IF showed nonsignificantly higher MCIC achievement (odds ratio [OR] = 1.20, 95% confidence interval [CI]: 0.66 to 2.17, p = 0.65) and lower COMI scores compared with the MD group (3.34 ± 2.89 versus 4.01 ± 2.95, p = 0.059; derived Oswestry Disability Index [ODI]: 23.8 versus 28.1). IF demonstrated significantly lower reoperation risk compared with MD (15.7% [116/316] versus 36.7% [21/34], p < 0.001). The reoperations following MD were predominantly subsequent IF (73.3%) and repeat MD (23.3%), while the reoperations after IF were predominantly adjacent segment surgery (57.1%) and hardware revision (33.3%). BMI of ≥35 kg/m 2 was a significant predictor of reoperation after MD (univariate OR = 3.63, p = 0.039), while disc height of <6 mm (OR = 1.97) and Modic type-1 changes (OR = 1.78) showed trends toward increased reoperation risk (both p < 0.10). CONCLUSIONS:Although both procedures achieved clinical improvement, IF demonstrated superior long-term durability as shown by significantly lower reoperation rates over extended follow-up. Our findings support a risk-stratified surgical selection: IF should be strongly considered in patients with BMI of ≥35 kg/m 2 and those with progressive disc degeneration, whereas MD remains appropriate for patients without these risk factors. LEVEL OF EVIDENCE:Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

To assess whether distal hyperlordotic distribution (DHD), defined by the Lordosis Distribution Index (LDI) from the Global Alignment and Proportion (GAP) score, increases the risk of mechanical complications (MC) in adult spinal deformity (ASD) patients with optimal postoperative global sagittal alignment and total lordosis after long-construct fusion to the pelvis. Retrospective analysis of a prospective, multicenter database. ASD patients undergoing fusion from L2 or higher to the pelvis with ≥ 2 years follow-up and optimal postoperative global alignment (RSA = 0) and total lordosis (RLL = 0), according to the GAP score, were included. Patients were classified into Ideal (LDI = 0) and DHD (LDI = 3) groups. Rates of MCs (stratified in PJK or PJF), reoperations, and functional outcomes were compared. A post-hoc non-inferiority analysis utilizing a 10

OBJECTIVE:The objective of this study was to evaluate the impact of four-rod (4R) constructs and interbody cages (IBCs) on pseudarthrosis and rod breakage (PA/RB) in patients with adult spinal deformity (ASD) who had undergone surgery with pelvic fixation and Schwab grade 2 osteotomies, using a combined finite element model (FEM) and clinical data analysis. METHODS:A validated FEM simulated Schwab grade 2 osteotomies at the L4-5 level in two-rod and 4R configurations, with or without IBCs at L4-5 and L5-S1. Rod strain and range of motion were calculated under a 7.5-Nm moment. Clinical analysis was conducted on ASD patients with pelvic fixation and Schwab grade 2 osteotomies and ≥ 2 years of follow-up. Patients were classified into 2 groups depending on the presence or absence of PA/RB. Demographic, surgical, radiographic, and patient-reported outcome measure (PROM) data were compared. RESULTS:The FEM analysis revealed maximal rod strain of 399 MPa at the osteotomy site in flexion. The 4R constructs and IBCs reduced strain to 114 MPa at L4-5 and 80 MPa at L5-S1. Among the 213 patients included in the study, PA/RB occurred in 61 (28.6%). Multivariate analysis revealed the use of 4R constructs (OR 0.331, 95% CI 0.16-0.71, p = 0.004) and IBCs (OR 0.46, 95% CI 0.23-0.94, p = 0.033) as protective factors. Patients with PA/RB experienced more unplanned reinterventions, worse scores on PROMs, and greater loss of sagittal alignment at 2 years postoperatively. CONCLUSIONS:Constructs with 4Rs and IBCs in ASD surgeries with pelvic fixation and Schwab grade 2 osteotomies significantly reduced rod strain and decreased the risk of PA/RB, leading to better scores on PROMs and decreasing unplanned reinterventions and loss of alignment.

Background:Accurate computation of radiological parameters related to spinal alignment is clinically crucial for diagnosing and managing conditions, such as adolescent idiopathic scoliosis and adult spinal deformities. Key parameters, including sacral slope, pelvic tilt, pelvic incidence, and lumbar lordosis, are required to assess lumbosacral alignment. Artificial Intelligence (AI) has demonstrated strong potential in automating these assessments, reducing clinician workload and improving consistency. However, AI models require large, diverse, high-quality datasets to perform reliably across different clinical settings. Privacy concerns and data ownership issues often hinder data sharing, limiting the creation of centralized datasets. Methods:In this study, we demonstrate that federated learning (FL) enables the training of deep learning models across four hospitals without compromising patient privacy. In particular, we compared FL against a centralized approach, where data from all the hospitals are pooled together and a model is trained on them, and a local approach consisting of training individual models exclusively on data from each respective hospital, resulting in distinct hospital-specific models. Results:FL achieved performance comparable to centralized training (errors ~5°), where data is pooled, and consistently outperformed models trained on data from individual hospitals, both in internal (~8°) and external (~10°) testing. Conclusion:This work highlights FL as a viable solution for collaborative AI development in spinal imaging, facilitating the use of diverse, multi-institutional data while circumventing privacy barriers and complex data-sharing agreements. Additionally, FL demonstrates particular benefits for smaller hospitals, enabling them to achieve superior model performance by effectively leveraging data from hospitals with larger datasets.

Cervical spondylosis can cause loss of lordosis or even kyphosis, altering sagittal alignment and triggering compensatory mechanisms to maintain horizontal gaze. Despite the widespread use of multilevel anterior cervical discectomy and fusion (ACDF), its impact on cervical sagittal alignment and compensatory mechanisms remains unclear. This study investigates degenerative changes in cervical sagittal alignment and compensatory mechanisms before and after multilevel ACDF. A retrospective analysis was conducted on 290 patients who underwent multilevel ACDF (2–3 levels) for cervical spondylosis. Preoperative and postoperative sagittal parameters including C0–C2 lordosis, C2–C7 lordosis, surgical (fused-level) lordosis, unfused-level lordosis, T1 slope (T1S), T1S minus cervical lordosis (T1S–CL), and cervical sagittal vertical axis (c–SVA) were measured using a previously described deep learning model. Demographic data were collected at the same time points. Changes from baseline to follow-up were calculated. Correlations between changes in surgical lordosis and sagittal parameters were assessed via linear regression, Pearson’s correlation, and multiple logistic regression analysis. Mean preoperative C2–C7 lordosis was 11.4° ± 13.7°, increasing by 6.5° in two-level, and 8.6° in three-level ACDF patients. Statistically significant improvements were observed in C2–C7 lordosis, C0–C2 lordosis, and T1S–CL mismatch (all p < 0.01). Changes in surgical lordosis correlated negatively with changes in unfused segment lordosis (R = − 0.26, p < 0.01). The strongest negative correlation was observed between changes in C2–C7 and changes in C0–C2 lordosis (R = − 0.60, p < 0.01), highlighting subaxial realignment’s impact on upper cervical compensation. A moderate positive correlation emerged between changes in surgical lordosis and changes in T1S (R = 0.29, p < 0.01). Subgroup analyses by fusion area confirmed the consistency of these relationships across different ACDF configurations. Multilevel ACDF leads to a gain of surgical lordosis and reduces compensatory mechanisms. By recognizing and accounting for preoperative compensatory mechanisms, surgeons can optimize surgical planning to achieve a more stable and biomechanically favorable alignment. We propose a three-step algorithm to analyze cervical sagittal alignment and take into consideration the presence of compensatory mechanisms of the upper cervical, the unfused subaxial and when available the global spine. IV.

The purpose of this study was to compare the S2-alar-iliac (S2AI) technique with the iliac screw (IS) technique in adult spinal deformity (ASD) patients in terms of clinical and radiographical outcomes, focusing on reoperations, complications, and change in radiographic parameters. This is a retrospective review of a prospective, multicenter database. ASD patients who underwent long fusion to the pelvis with 2-year postoperative follow-up were included. To compare outcomes (radiographic, clinical, and complications), matching was performed based on the type of pelvic fixation (IS vs. S2AI) using propensity score matching (PSM), 1:1 ratio, caliper 0.1, tolerance ≤ 0.001, with a 95

Mechanical complications after adult deformity surgery are typically considered as a composite variable. This study aims to differentiate their characteristics and analyze their behavioral patterns based on time-to-onset and predisposing factors. This retrospective observational study analyzed patients from a prospective multicenter database. Operated patients were analyzed for proximal junctional kyphosis (PJK), proximal junctional failure (PJF), pseudarthrosis (PA), rod breakage (RB), and no complications. Kaplan–Meier survival analysis and multivariate Cox regression models encompassing clinical, biological, radiographic, and surgical parameters were utilized to identify complication-related factors. Among 1,505 patients analyzed, 260 (17.3

Purpose Proximal junctional kyphosis (PJK) is a common complication after fusion surgery for adult spinal deformity (ASD). Tissue adaptation to deformity may cause abdominal wall shortening/stiffening. This study evaluated, using musculoskeletal modeling, the effect of these adaptations and sarcopenia on trunk muscle effort required to maintain postoperative alignment in PJK patients versus controls. Methods ASD patient data was grouped by mechanical complication status: PJK (N=44), other (N=56), none (N=260). Spinopelvic landmarks were annotated in pre-op, post-op, and follow-up X-ray images. Patient-specific musculoskeletal models of corresponding alignments were built. Forces due to stretching of the abdominal wall beyond pre-op length (assumed slack) were applied, representing abdominal wall stiffness. Sarcopenia was implemented by reducing paraspinal muscle strength based on patient age and gender. Inverse-static simulations predicted overall muscle effort by summing muscle activities. Results Postoperatively, the abdominal wall was more elongated in the PJK group (+8.4%[-0.3;20.0]) versus the no-complication group (+2.4%[-4.9;10.2], p<0.01) due to larger preoperative deformities and greater surgical correction. This elongation correlated more with pelvic tilt change (r=-0.53) than lumbar lordosis correction (r=0.16). Greater muscle effort was estimated for post-op alignment in the PJK group (12.40[6.42;28.6]) versus the no-complication group (8.42[4.34;13.3], p<0.05). Muscle effort was reduced at follow-up in groups with mechanical complications. Conclusion Alignment restoration tensions abdominal structures, requiring increased extensor muscle forces to maintain postoperative alignment. Patients might develop PJK to reduce unsustainable muscle effort or due to spinal structure failure. More attention should be given to pelvic reciprocal changes to improve surgical planning and perioperative rehabilitation.

To evaluate a novel proximal thoracic concave rod (PTCR) technique for improving postoperative shoulder imbalance (SI) in adolescent idiopathic scoliosis (AIS) patients with Lenke types 2 and 4 curves, compared to conventional methods. A retrospective study of 30 AIS patients (10 with PTCR, 20 without) from a multicentric European database was conducted. Patients aged ≤ 18 years undergoing surgery for Lenke types 2 or 4 curves with ≥ 2 years of follow-up were included. Radiographic parameters, including Clavicle Angle (CA) and T1 Coronal Tilt (T1CT), were assessed preoperatively, immediately postoperatively, and at 2 years. Demographic, surgical, radiological parameters, and patient-reported outcomes measures (PROMs) were compared between groups. PTCR significantly improved SI, achieving optimal CA in 80

Spinal deformity can have a severe impact on the patient’s sexual health. Eventually, this can lead to depression and relationship distress. Spinal surgical management is suggested to improve sexual function, however, the literature concerning these aspects is still scarce. This study evaluated which factors predicted improvement in sexual health in patients with adult spinal deformity (ASD) who underwent surgical treatment. Multicentric retrospective study based on a prospectively collected ASD database. Data of patients who underwent surgical correction and had a 2-year follow-up were collected. The association between different patient-reported outcome measures and ODI question 8 (Q8, sexual health) was explored with Pearson correlations and Principal Component Analysis (PCA). Improvement in sexual health was evaluated through a 1-point decrease on Q8. Comparisons between improved and non-improved patients and the non-response to the preoperative Q8 were assessed. Data from 880 patients were collected. Moderate correlations were revealed between ODI and COMI-back, SRS-22, and SF-36 items and confirmed with PCA. The main factors associated to a non-response to Q8 were being of an older age, having worse sagittal imbalance, and having a specific nationality. Patients with an improvement in sexual health at 2 years were the ones with a worse baseline quality of life, older patients with a greater sagittal correction, and a better improvement of the level of physical activity. Non-response to Q8 was correlated to age and nationality. Long-segment ASD surgery could improve sexual health, which was correlated to physical activity improvement, severe deformity with worse preoperative quality of life, and better postoperative sagittal correction.