Dynamic remodeling of pelvic sagittal and hip coronal parameters after posterior spinal fusion in adolescent idiopathic scoliosis

Dynamic remodeling of pelvic sagittal and hip coronal parameters after posterior spinal fusion in adolescent idiopathic scoliosis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Dynamic remodeling of pelvic sagittal and hip coronal parameters after posterior spinal fusion in adolescent idiopathic scoliosis Zhou Anli, Shen Xinhe, Cheng Jia, Sun Zhihang, Tang Hao, Li Wenjin, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7782644/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 17 You are reading this latest preprint version Abstract Background Adolescent idiopathic scoliosis (AIS) correction may influence pelvic sagittal alignment and hip coronal morphology, but growth-stage trajectories remain unclear. Methods We retrospectively included 138 female AIS patients who underwent posterior spinal fusion (PSIF). Standing full-length spine–pelvis radiographs were obtained preoperatively and at 6 months, 1 year, and 2 years postoperatively. Parameters included Cobb angle, lateral center–edge angle (LCEA), Tönnis angle, iliac obliquity (IO), sacral obliquity (SO), and pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Analyses were stratified by age (10–14 vs 15–18 years) and Lenke type (1 vs 5). Within-subject comparisons used repeated-measures ANOVA or Friedman tests with Bonferroni-adjusted pairwise tests; between-group tests and correlations used standard parametric/non-parametric procedures. Results Age- and Lenke-specific remodeling patterns were evident. In 10–14-year-olds with Lenke 1, Tönnis decreased (right − 2.25° at 6 months; left − 2.72° at 2 years) and SS increased at 2 years (+ 3.27°). In 10–14-year-olds with Lenke 5, right LCEA increased at 2 years (+ 3.26°) while both Tönnis angles decreased (− 3.54° and − 3.31°). Changes were small in 15–18-year-olds; only Lenke 5 showed a slight increase in left Tönnis at 1 year (+ 0.95°). Conclusions Pelvis–hip parameters remodel within two years after PSIF, with greater improvements in acetabular coverage and sagittal adaptation among younger adolescents (10–14 years), especially Lenke 1/5, suggesting higher biomechanical plasticity before skeletal maturity. Routine postoperative assessment should incorporate pelvis–hip parameters with age/Lenke context to inform long-term management. adolescent idiopathic scoliosis posterior spinal fusion pelvis hip Lenke classification Figures Figure 1 Figure 2 Background AIS is the most common scoliosis subtype in adolescents, affecting approximately 2–3% of this population. 1,2 Posterior spinal fusion (PSIF) is a standard surgical approach to correct deformity and restore global balance. 3 While deformity correction is effective, the dynamic impact of PSIF on pelvic parameters—particularly coronal (IO, SO) and on hip morphology (e.g., LCEA, Tönnis) and long-term biomechanics has not been systematically characterized. Emerging evidence suggests that alterations in hip morphology can significantly influence spinopelvic biomechanics. For instance, Kerboull et al. reported in multiple studies 4 – 6 improvements in spinal symptoms following total hip arthroplasty (THA), regardless of whether the hip was stable 5 or unstable 6 postoperatively. Qu et al. 7 also confirmed via finite element analysis that curved periacetabular osteotomy (CPO) effectively regulates hip contact pressure while reducing lumbar intervertebral disc contact pressure. However, the specific effects of spinal deformity correction surgery, particularly in skeletally immature adolescents, on acetabular morphology, coverage, and hip joint load distribution are poorly understood. Therefore, This study aimed to: (1) delineate the two-year postoperative trajectories of pelvic sagittal (PI, PT, SS) and hip coronal (LCEA, Tönnis angle) parameters in AIS; and (2) evaluate whether remodeling patterns differ by Lenke classification (primarily types 1 vs 5) and by age (10–14 vs 15–18 years). Methods Study design and ethics: This single-center retrospective cohort included female AIS patients treated with PSIF from January 2020 to September 2024. Data were de-identified; the protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Kunming Medical University with a waiver of consent (FEY-BG-39-3.0). Participants: We limited the cohort to females to reduce sex-related differences in pelvic/acetabular geometry and in AIS progression risk, improving within-cohort homogeneity and statistical power 2 , 8 . Inclusion criteria: (1) AIS diagnosis; (2) PSIF; (3) age 10–18 years at surgery. Exclusion: non-idiopathic scoliosis (congenital/neuromuscular), prior hip/pelvic surgery. Radiographic acquisition and measurements: Standing full-length anteroposterior and lateral spine–pelvis radiographs were obtained preoperatively and at 6 months, 1 year, and 2 years postoperatively. Hip parameters included(Fig. 1 ): LCEA, reflecting acetabular coverage 9 ; and the Tönnis angle, indexing acetabular inclination 10 . Coronal pelvic balance was characterized by IO and SO 11 ; sagittal pelvic alignment by PI, PT, and SS 12 . Two observers independently measured all parameters and repeated measurements in a random sample (n = 50) to calculate intraclass correlation coefficient (ICCs) (> 0.85 for Cobb, LCEA, Tönnis). Stratification: Based on growth-related evolution of spinopelvic parameters and differences in compensation pathways across Lenke patterns 13 , stratification was pre-specified by age (10–14 vs 15–18 years) and Lenke type (1 vs 5). Lenke classification followed the original description. 14 Statistical analysis: Analyses used SPSS 26.0. Missing values were addressed via multiple imputation 15. Continuous variables were tested by Shapiro–Wilk (normality) and Levene’s (homoscedasticity). Within-subject comparisons (baseline, 6 months, 1 year, 2 years) used repeated-measures ANOVA for normal variables and Friedman tests otherwise; pairwise comparisons versus baseline were Bonferroni-adjusted. Between-group comparisons used independent-samples t tests or Mann–Whitney U tests as appropriate; correlations used Spearman’s rho. Two-sided P < 0.05 was considered significant. Results A total of 138 female AIS patients were included. Lenke distribution: type 1 (n = 79), type 5 (n = 36). Other Lenke types were underpowered (type 2: n = 4; type 3: n = 7; type 4: n = 3; type 6: n = 9) and not included in inferential analyses. Key significant within-subject changes after Bonferroni correction are summarized inTable 1 and Fig. 2 ; complete values for each Age × Lenke subgroup at all timepoints are presented in Additional file 1 (Tables S1–S4). Among 10–14-year-olds with Lenke 1: right Tönnis decreased at 6 months (median Δ − 2.25°; 9.7→7.45), left Tönnis decreased at 2 years (− 2.72°; 10.3→7.58), and SS increased at 2 years (+ 3.27°; 35.55→38.82). Among 10–14-year-olds with Lenke 5: right LCEA increased at 2 years (+ 3.26°; 30.7→33.96), and both left and right Tönnis decreased at 2 years (− 3.54° and − 3.31°, respectively). Among 15–18-year-olds: Lenke 1 showed no significant changes versus baseline after Bonferroni adjustment. Lenke 5 exhibited a slight increase in left Tönnis at 1 year (+ 0.95°; 7.65→8.60). Table 1 Key significant postoperative changes versus preoperative baseline after Bonferroni correction across Age × Lenke subgroups Subgroup Parameter Timepoint Median (Pre) Median (Time) Delta (time − pre) n (paired) P (adjusted) Dir 10–14 yrs & Lenke 1 Tönnis left 2 years 10.3 7.58 -2.72 48 < 0.001 ↓ 10–14 yrs & Lenke 1 Tönnis right 6 months 9.7 7.45 -2.25 48 0.026 ↓ 10–14 yrs & Lenke 1 SS 2 years 35.55 38.82 3.27 48 0.030 ↑ 10–14 yrs & Lenke 5 LCEA right 2 years 30.7 33.96 3.26 24 0.045 ↑ 10–14 yrs & Lenke 5 Tönnis left 2 years 11.2 7.66 -3.54 24 0.024 ↓ 10–14 yrs & Lenke 5 Tönnis right 2 years 10.65 7.34 -3.31 24 0.014 ↓ 15–18 yrs & Lenke 5 Tönnis left 1 year 7.65 8.6 0.95 12 0.021 ↑ Data are presented as median [IQR]. P values are Bonferroni-adjusted for three pairwise comparisons (6 months, 1 year, 2 years vs baseline) within each parameter. “n (paired)” denotes the number of subjects with paired data at the indicated timepoint. Full numerical results are provided in Additional file 1: Tables S1–S4. Discussion In this two-year postoperative cohort, pelvis–hip remodeling depended on Lenke type and age: younger (10–14 years) Lenke 1/5 patients showed improved acetabular coverage (lower Tönnis) and modest sagittal adaptation (higher SS), whereas changes in 15–18-year-olds were small. These findings support viewing the spine–pelvis–hip as an integrated, dynamic unit and considering skeletal maturity in outcome evaluation. The decreases in Tönnis and increases in LCEA in younger adolescents indicate improved acetabular coverage, a favorable morphological signal. In contrast, adult studies have associated longer fusions with increased hip loading and higher risks of joint-space narrowing or osteoarthritis 16 , 17 , 18 . The most plausible explanation is that the biological and geometric plasticity present during growth may offset the adverse hip effects of fusion. This difference underscores that, although the procedure is the same, the direction and magnitude of the hip–pelvis response vary by age group. Unlike the observation by Si et al. in adult spinal deformity—where hip pain correlated with pelvic parameters but morphological improvement was not reported 19 —our participants had open physes; their articular cartilage and periarticular soft tissues are in an active growth phase 13 , conferring greater capacity for adaptive reconstruction. Notably, unlike the pronounced coronal pelvic compensation described in developmental dysplasia cohorts 11 , we did not observe substantial coronal pelvic compensation after correction, suggesting more direct changes in load transmission rather than sacroiliac ‘buffering’. Age and skeletal maturity emerged as key moderators: greater Tönnis/LCEA and SS changes in 10–14 years suggest stronger tissue and geometric plasticity, whereas older adolescents showed limited changes, implying that plasticity weakens as physeal closure approaches and the magnitude of remodeling diminishes. These results align with prior studies on the growth-related evolution of pelvic sagittal parameters 17 , 20 and support using developmental stage as an important stratification and decision-making dimension in clinical care. Second, postoperative follow-up of AIS should routinely and systematically monitor pelvic and hip parameters to comprehensively evaluate how surgery affects global load paths. Finally, because adolescents remain in active development, the 2-year follow-up window used in this study may be insufficient to capture the eventual steady state of these adaptive changes; we therefore strongly recommend extending follow-up into skeletal maturity (e.g., 5 and 10 years postoperatively) to determine whether the early favorable changes are sustained and to assess their long-term implications for adult hip health and spinopelvic function. Limitations This retrospective single-center study limits generalizability. The cohort comprised females only; extrapolation to males should be cautious, and sex-by-Lenke interactions merit testing in future work. Inferential analyses focused on Lenke 1/5 due to underpowered subtypes, which may introduce selection bias; conclusions primarily apply to Lenke 1/5 AIS. Standing posture and residual rotation may influence absolute values of LCEA, Tönnis, and PI/PT/SS despite standardized imaging and sensitivity checks; thus, we emphasize within-subject longitudinal changes over cross-sectional absolutes. Finally, the two-year follow-up captures early adaptation but may not reflect the eventual steady state; longer-term follow-up to skeletal maturity is needed. Conclusions Pelvic and hip parameters remodel within two years after PSIF in AIS, with age- and Lenke-specific patterns. Younger patients—particularly those aged 10–14 years with Lenke 1/5—show improved acetabular coverage and adaptive sagittal changes, whereas older adolescents change little. Postoperative assessment should routinely incorporate pelvis–hip parameters and account for age and curve type to enable tailored long-term management, with extended follow-up to confirm durability of early improvements. Declarations Ethics approval and consent to participate : Approved by the Ethics Committee of the Second Affiliated Hospital of Kunming Medical University (FEY-BG-39-3.0); consent was waived for this de-identified retrospective analysis. Ethics approval and consent to participate. All procedures performed on this study were in accordance with the ethical standards of the 1964 Helsinki declaration. Consent for publication : Not applicable. Availability of data and materials : The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests : The authors declare that they have no competing interests. Funding : This study was supported by the External Cooperation Research Project of the Second Affiliated Hospital of Kunming Medical University, Yunnan Province, China (Grant No. 2022dwhz19) and Yunnan Provincial Science and Technology Program (Grant No. 202501AY070001-034 Authors’ contributions : Zhou Anli and Lu Ning wrote the main manuscript text. Zhao Zhi, Li Tao, and Wang Yingsong provided the patient data materials. Cheng Jia, Sun Zhihang, and Shen Xinhe collected the data. Tang Hao and Li Wenjin performed the data analysis. All authors reviewed and approved the final version of the manuscript. Supplementary Information : Additional file 1: Tables S1–S4 (complete numeric results for each subgroup and timepoint) Clinical trial number : not applicable References Weinstein SL, Dolan LA, Cheng JC, et al. Adolescent idiopathic scoliosis. Lancet. 2008;371(9623):1527–37. Konieczny MR, Senyurt H, Krauspe R. Epidemiology of adolescent idiopathic scoliosis. J Child Orthop. 2013;7(1):3–9. 10.1007/s11832-012-0457-4 . Tsirikos AI, Mataliotakis G, Bounakis N. Posterior spinal fusion for adolescent idiopathic scoliosis using a convex pedicle screw technique. Bone Joint J. 2017;99–B(8):1080–7. 10.1302/0301-620X.99B8.BJJ-2016-1351.R1 . Kerboull M. Le retentissement sur le genou des déformations invétérées de la hanche. Conférences d’enseignement de la SOFCOT. Paris: Expansion scientifique française (1990): 129–149. Hamadouche M et al. Total hip arthroplasty for the treatment of ankylosed hips: a five to twenty-one-year follow-up study. JBJS 83.7 (2001): 992–998. Kerboull M, Hamadouche M, Kerboull L. Total hip arthroplasty for Crowe type IV developmental hip dysplasia: a long-term follow-up study. J Arthroplast. 2001;16(8):170–6. Qu Y, Tang H, Lu N, Li W, Xu P, Zhou T. Biomechanical changes in the lumbar and hip joint after curved periacetabular osteotomy. J Orthop Surg Res. 2024;19(1):770. 10.1186/s13018-024-05250-5 . Published 2024 Nov 19. Lonstein JE, Carlson JM. The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg Am. 1984;66(7):1061–71. Mannava S, Geeslin AG, Frangiamore SJ et al. Comprehensive Clinical Evaluation of Femoroacetabular Impingement: Part 2, Plain Radiography. Arthrosc Tech. 2017;6(5):e2003-e2009. Published 2017 Oct 30. 10.1016/j.eats.2017.06.011 Clohisy JC, Carlisle JC, Beaulé PE, et al. A systematic approach to the plain radiographic evaluation of the young adult hip. J Bone Joint Surg Am. 2008;90(4):47–66. 10.2106/JBJS.H.00756 . Yu Y, Song K, Wu B, et al. Coronal Compensation Mechanism of Pelvic Obliquity in Patients With Developmental Dysplasia of the Hip. GLOB SPINE J. 2021;13(4):949–53. 10.1177/219256822110107601 . Vialle R, Levassor N, Rillardon L, Templier A, Skalli W, Guigui P. Radiographic analysis of the sagittal alignment and balance of the spine in asymptomatic subjects. J Bone Joint Surg Am. 2005;87(2):260–7. 10.2106/JBJS.D.02043 . Mac-Thiong JM, Berthonnaud E, Dimar JR 2nd, Betz RR, Labelle H. Sagittal alignment of the spine and pelvis during growth. Spine (Phila Pa 1976). 2004;29(15):1642–7. 10.1097/01.brs.0000132312.78469.7b . Lenke LG, Betz RR, Harms J, et al. Adolescent idiopathic scoliosis: a new classification to determine extent of spinal arthrodesis. J Bone Joint Surg Am. 2001;83(8):1169–81. Sterne JA, White IR, Carlin JB, et al. Multiple imputation for missing data in epidemiological and clinical research: Potential and pitfalls. BMJ. 2009;338:b2393. Ukai T, Katoh H, Yokoyama K, Sato M, Watanabe M. Effect of spinal fusion on joint space narrowing of the hip: comparison among non-fusion, short fusion, and middle or long fusion. J Orthop Traumatol. 2023;24(1):1. Published 2023 Jan 9. 10.1186/s10195-022-00682-3 Kawai T, Shimizu T, Goto K, et al. Number of Levels of Spinal Fusion Associated with the Rate of Joint-Space Narrowing in the Hip. J Bone Joint Surg Am. 2021;103(11):953–60. 10.2106/JBJS.20.01578 . Ulusoy İ, Kıvrak A. Lumbosacral fusion increases the risk of hip osteoarthritis. J Orthop Surg Res. 2023;18(1):452. 10.1186/s13018-023-03932-0 . Published 2023 Jun 24. Si G, Li T, Liu X, Liu Z, Li W, Yu M. Correlation analysis between postoperative hip pain and spino-pelvic/hip parameters in adult scoliosis patients after long-segment spinal fusion. Eur Spine J. 2020;29(12):2990–7. 10.1007/s00586-020-06316-8 . Chatelain LS, Simon AL, Khalifé M, Ferrero E. Pediatric spinal alignment and spinal development. N Am Spine Soc J. 2024;20:100548. 10.1016/j.xnsj.2024.100548 . Published 2024 Aug 13. Additional Declarations No competing interests reported. Supplementary Files tables1s4.docx Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 17 Mar, 2026 Reviews received at journal 08 Mar, 2026 Reviewers agreed at journal 28 Feb, 2026 Reviewers agreed at journal 26 Feb, 2026 Reviewers agreed at journal 26 Feb, 2026 Reviews received at journal 26 Feb, 2026 Reviews received at journal 25 Feb, 2026 Reviewers agreed at journal 23 Feb, 2026 Reviewers agreed at journal 23 Feb, 2026 Reviewers agreed at journal 23 Feb, 2026 Reviewers agreed at journal 23 Feb, 2026 Reviewers agreed at journal 06 Feb, 2026 Editor invited by journal 20 Jan, 2026 Reviewers invited by journal 02 Nov, 2025 Editor assigned by journal 11 Oct, 2025 Submission checks completed at journal 11 Oct, 2025 First submitted to journal 04 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7782644","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":541677370,"identity":"c6d7e23c-1f4b-4435-ac50-f669383a42fb","order_by":0,"name":"Zhou Anli","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zhou","middleName":"","lastName":"Anli","suffix":""},{"id":541677371,"identity":"b55322ff-f9b4-4a57-bd13-1ec22338d8cd","order_by":1,"name":"Shen Xinhe","email":"","orcid":"","institution":"Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shen","middleName":"","lastName":"Xinhe","suffix":""},{"id":541677372,"identity":"454ad027-b1ea-47bf-a155-57fadf331796","order_by":2,"name":"Cheng Jia","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Cheng","middleName":"","lastName":"Jia","suffix":""},{"id":541677373,"identity":"b2d85e1f-1a03-47c6-94d0-cc4ae0d9f194","order_by":3,"name":"Sun Zhihang","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Sun","middleName":"","lastName":"Zhihang","suffix":""},{"id":541677374,"identity":"4733a62d-5cbd-4d7a-b745-1170cd4a025f","order_by":4,"name":"Tang Hao","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Tang","middleName":"","lastName":"Hao","suffix":""},{"id":541677375,"identity":"7c719145-251f-40c8-a9e3-d2c7429ac434","order_by":5,"name":"Li Wenjin","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Li","middleName":"","lastName":"Wenjin","suffix":""},{"id":541677376,"identity":"89672b8d-b856-4f5c-87d8-3a3d4a979e20","order_by":6,"name":"Zhao Zhi","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zhao","middleName":"","lastName":"Zhi","suffix":""},{"id":541677379,"identity":"88288ca0-3be1-4dee-98e3-67e89612b068","order_by":7,"name":"Li Tao","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Li","middleName":"","lastName":"Tao","suffix":""},{"id":541677381,"identity":"548e39c9-c5da-48be-b8b5-76ba91cc1740","order_by":8,"name":"Wang Yingsong","email":"","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":false,"prefix":"","firstName":"Wang","middleName":"","lastName":"Yingsong","suffix":""},{"id":541677383,"identity":"0177294f-6d8d-4500-bcbb-e9bbb88162ca","order_by":9,"name":"Lu Ning","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzUlEQVRIiWNgGAWjYBACPiA+AGKwsTcfOPDhBxFa2OBaeI4lHpzZQ6QWCJDIMT7MwYZHKVyLRO7BwwW/DsvxMeR8OMzAwyDPL3aAkJa8hMMz+w4bszGc3XC4wILBcObsBEJacgwO8/bcTmxj7N1weAYPQ4LBbSK11Lcx8zw4zMNGrBaeH7cT2Nh4GIjUwvMGaEvDf8M2HjYDYCBLEPYLP3uO8WeeP2ny8vMfP/7w4YeNPL80AS1gwNgGZ0oQoRwM/hCrcBSMglEwCkYkAACcoUPbxZTLbQAAAABJRU5ErkJggg==","orcid":"","institution":"The Second Affiliated Hospital of Kunming Medical University","correspondingAuthor":true,"prefix":"","firstName":"Lu","middleName":"","lastName":"Ning","suffix":""}],"badges":[],"createdAt":"2025-10-05 04:08:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7782644/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7782644/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":95806792,"identity":"f856eebe-77e0-4d55-aebc-353162d8570b","added_by":"auto","created_at":"2025-11-13 08:47:53","extension":"jpg","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":54755,"visible":true,"origin":"","legend":"","description":"","filename":"figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/260157fdc6c3f0c21e4bd9dc.jpg"},{"id":95807152,"identity":"1fc1ac3e-dd4b-486a-85ac-1795de58d33c","added_by":"auto","created_at":"2025-11-13 08:48:09","extension":"jpg","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":190373,"visible":true,"origin":"","legend":"","description":"","filename":"figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/40815bd218c092ffbe1e2b25.jpg"},{"id":95806911,"identity":"24d0c8e2-b473-48e6-ab37-051029250ecd","added_by":"auto","created_at":"2025-11-13 08:47:59","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":347480,"visible":true,"origin":"","legend":"","description":"","filename":"Dynamicremodelingofpelvicsagittalandhipcoronalparametersafterposteriorspinalfusioninadolescentidiopathicscoliosis.docx","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/5c558cca835d074f3d7a56c0.docx"},{"id":95807223,"identity":"ddf468a7-e611-4b25-9d29-c455e2cc1100","added_by":"auto","created_at":"2025-11-13 08:48:14","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":18138,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/3c8d4647fd5b23c7e6a345dd.docx"},{"id":95807312,"identity":"9b9e6106-8218-45b6-a5fd-b9a12d022e2d","added_by":"auto","created_at":"2025-11-13 08:48:19","extension":"json","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":10511,"visible":true,"origin":"","legend":"","description":"","filename":"150eb5c808b7402e91af910f6b724347.json","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/d0b65bd5e995de7cfedb9701.json"},{"id":95806818,"identity":"b0bb6c9f-12f5-4190-aeaa-e19dafdf184d","added_by":"auto","created_at":"2025-11-13 08:47:55","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":34344,"visible":true,"origin":"","legend":"","description":"","filename":"tables1s4.docx","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/e4ca1c883c250fb6687069cf.docx"},{"id":95807096,"identity":"99184763-b715-4458-9e8f-4f9b1a7de9f9","added_by":"auto","created_at":"2025-11-13 08:48:06","extension":"xml","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64686,"visible":true,"origin":"","legend":"","description":"","filename":"150eb5c808b7402e91af910f6b7243471enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/944640b1123f55853ff44253.xml"},{"id":95807214,"identity":"82c1a678-918f-4bea-9507-59701b968f5f","added_by":"auto","created_at":"2025-11-13 08:48:13","extension":"jpg","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":54755,"visible":true,"origin":"","legend":"","description":"","filename":"figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/5591afe0d6af9553fd75967b.jpg"},{"id":95806894,"identity":"9b5da752-c347-4bd0-8983-f695bdf1ebfa","added_by":"auto","created_at":"2025-11-13 08:47:59","extension":"jpg","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":190373,"visible":true,"origin":"","legend":"","description":"","filename":"figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/215de8cfb4ec37c83dd58b37.jpg"},{"id":95806733,"identity":"d84aeb1b-a22e-4fd8-b048-739cb8e208f8","added_by":"auto","created_at":"2025-11-13 08:47:51","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":203022,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/86cf94a029afcd805bb0fdbb.png"},{"id":95806989,"identity":"dd96c547-43d2-47f8-a48c-2299a6851cc3","added_by":"auto","created_at":"2025-11-13 08:48:01","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":102644,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/4f945dd19d8df72096058bb8.png"},{"id":95807146,"identity":"c1c8f4db-3684-4be2-9af6-1e30e4938ba2","added_by":"auto","created_at":"2025-11-13 08:48:09","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":33160,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefigure1.png","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/486197fec53710cdd60588de.png"},{"id":95806934,"identity":"bda97166-3137-4471-b37f-53d288098350","added_by":"auto","created_at":"2025-11-13 08:48:00","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":42702,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefigure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/df83bec54b941ce68935f1cf.png"},{"id":95806993,"identity":"0b56bd0a-7ab6-461f-93aa-51061d515d03","added_by":"auto","created_at":"2025-11-13 08:48:02","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":32310,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/2ee6905a508f30297a53f2c4.png"},{"id":95806900,"identity":"9adb0673-3dd1-4afd-a12f-9e1715750c8d","added_by":"auto","created_at":"2025-11-13 08:47:59","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13842,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/cbd0c80c37f94f572b7399e9.png"},{"id":95807002,"identity":"9638665d-4a9a-4149-bcd7-e859be8aa113","added_by":"auto","created_at":"2025-11-13 08:48:03","extension":"xml","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64230,"visible":true,"origin":"","legend":"","description":"","filename":"150eb5c808b7402e91af910f6b7243471structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/f0d580a1175d888ad05c8566.xml"},{"id":95807129,"identity":"7160d0fc-3f5c-4f0c-9e45-86c273c65f8e","added_by":"auto","created_at":"2025-11-13 08:48:07","extension":"html","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":71196,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/5be842275f386ee07876c2e1.html"},{"id":95806765,"identity":"3a1c390b-98b2-45b7-9904-4a93df0d1652","added_by":"auto","created_at":"2025-11-13 08:47:52","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":54755,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurement of spinal, pelvic, and hip parameters\u003c/p\u003e","description":"","filename":"figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/b73da6f64b5af39802d0f0f4.jpg"},{"id":95807092,"identity":"888afc59-f03f-43da-8846-3a2a2c8380d6","added_by":"auto","created_at":"2025-11-13 08:48:06","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":190373,"visible":true,"origin":"","legend":"\u003cp\u003esignificant postoperative changes\u003c/p\u003e","description":"","filename":"figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/b5bbb4bc2a0f45b34e3d88f1.jpg"},{"id":95810367,"identity":"ac7b3824-13ff-4610-8f4f-3cf4e4456bb7","added_by":"auto","created_at":"2025-11-13 08:52:30","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":761770,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/a64ef082-6a5a-4cb3-8b9e-ee30e081f943.pdf"},{"id":95807219,"identity":"9e21a825-a26e-47ec-bc5a-e44a42243782","added_by":"auto","created_at":"2025-11-13 08:48:13","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":34344,"visible":true,"origin":"","legend":"","description":"","filename":"tables1s4.docx","url":"https://assets-eu.researchsquare.com/files/rs-7782644/v1/e8bb5b0375080453b4e0bbaf.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Dynamic remodeling of pelvic sagittal and hip coronal parameters after posterior spinal fusion in adolescent idiopathic scoliosis","fulltext":[{"header":"Background","content":"\u003cp\u003eAIS is the most common scoliosis subtype in adolescents, affecting approximately 2\u0026ndash;3% of this population. \u003csup\u003e1,2\u003c/sup\u003e\u003c/p\u003e\u003cp\u003ePosterior spinal fusion (PSIF) is a standard surgical approach to correct deformity and restore global balance. \u003csup\u003e3\u003c/sup\u003e While deformity correction is effective, the dynamic impact of PSIF on pelvic parameters\u0026mdash;particularly coronal (IO, SO) and on hip morphology (e.g., LCEA, T\u0026ouml;nnis) and long-term biomechanics has not been systematically characterized.\u003c/p\u003e\u003cp\u003eEmerging evidence suggests that alterations in hip morphology can significantly influence spinopelvic biomechanics. For instance, Kerboull et al. reported in multiple studies\u003csup\u003e\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e improvements in spinal symptoms following total hip arthroplasty (THA), regardless of whether the hip was stable\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e or unstable\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e postoperatively. Qu et al.\u003csup\u003e7\u003c/sup\u003e also confirmed via finite element analysis that curved periacetabular osteotomy (CPO) effectively regulates hip contact pressure while reducing lumbar intervertebral disc contact pressure. However, the specific effects of spinal deformity correction surgery, particularly in skeletally immature adolescents, on acetabular morphology, coverage, and hip joint load distribution are poorly understood. Therefore, This study aimed to: (1) delineate the two-year postoperative trajectories of pelvic sagittal (PI, PT, SS) and hip coronal (LCEA, T\u0026ouml;nnis angle) parameters in AIS; and (2) evaluate whether remodeling patterns differ by Lenke classification (primarily types 1 vs 5) and by age (10\u0026ndash;14 vs 15\u0026ndash;18 years).\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e Study design and ethics: This single-center retrospective cohort included female AIS patients treated with PSIF from January 2020 to September 2024. Data were de-identified; the protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Kunming Medical University with a waiver of consent (FEY-BG-39-3.0).\u003c/p\u003e\u003cp\u003eParticipants: We limited the cohort to females to reduce sex-related differences in pelvic/acetabular geometry and in AIS progression risk, improving within-cohort homogeneity and statistical power \u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Inclusion criteria: (1) AIS diagnosis; (2) PSIF; (3) age 10\u0026ndash;18 years at surgery. Exclusion: non-idiopathic scoliosis (congenital/neuromuscular), prior hip/pelvic surgery.\u003c/p\u003e\u003cp\u003eRadiographic acquisition and measurements: Standing full-length anteroposterior and lateral spine\u0026ndash;pelvis radiographs were obtained preoperatively and at 6 months, 1 year, and 2 years postoperatively. Hip parameters included(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e): LCEA, reflecting acetabular coverage \u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e; and the T\u0026ouml;nnis angle, indexing acetabular inclination \u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. Coronal pelvic balance was characterized by IO and SO \u003csup\u003e11\u003c/sup\u003e; sagittal pelvic alignment by PI, PT, and SS \u003csup\u003e12\u003c/sup\u003e. Two observers independently measured all parameters and repeated measurements in a random sample (n\u0026thinsp;=\u0026thinsp;50) to calculate intraclass correlation coefficient (ICCs) (\u0026gt;\u0026thinsp;0.85 for Cobb, LCEA, T\u0026ouml;nnis).\u003c/p\u003e\u003cp\u003eStratification: Based on growth-related evolution of spinopelvic parameters and differences in compensation pathways across Lenke patterns \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e, stratification was pre-specified by age (10\u0026ndash;14 vs 15\u0026ndash;18 years) and Lenke type (1 vs 5). Lenke classification followed the original description. \u003csup\u003e14\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eStatistical analysis: Analyses used SPSS 26.0. Missing values were addressed via multiple imputation 15. Continuous variables were tested by Shapiro\u0026ndash;Wilk (normality) and Levene\u0026rsquo;s (homoscedasticity). Within-subject comparisons (baseline, 6 months, 1 year, 2 years) used repeated-measures ANOVA for normal variables and Friedman tests otherwise; pairwise comparisons versus baseline were Bonferroni-adjusted. Between-group comparisons used independent-samples t tests or Mann\u0026ndash;Whitney U tests as appropriate; correlations used Spearman\u0026rsquo;s rho. Two-sided P\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered significant.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 138 female AIS patients were included. Lenke distribution: type 1 (n\u0026thinsp;=\u0026thinsp;79), type 5 (n\u0026thinsp;=\u0026thinsp;36). Other Lenke types were underpowered (type 2: n\u0026thinsp;=\u0026thinsp;4; type 3: n\u0026thinsp;=\u0026thinsp;7; type 4: n\u0026thinsp;=\u0026thinsp;3; type 6: n\u0026thinsp;=\u0026thinsp;9) and not included in inferential analyses. Key significant within-subject changes after Bonferroni correction are summarized inTable 1 and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e; complete values for each Age \u0026times; Lenke subgroup at all timepoints are presented in Additional file 1 (Tables S1\u0026ndash;S4).\u003c/p\u003e\u003cp\u003eAmong 10\u0026ndash;14-year-olds with Lenke 1: right T\u0026ouml;nnis decreased at 6 months (median Δ\u0026thinsp;\u0026minus;\u0026thinsp;2.25\u0026deg;; 9.7\u0026rarr;7.45), left T\u0026ouml;nnis decreased at 2 years (\u0026minus;\u0026thinsp;2.72\u0026deg;; 10.3\u0026rarr;7.58), and SS increased at 2 years (+\u0026thinsp;3.27\u0026deg;; 35.55\u0026rarr;38.82).\u003c/p\u003e\u003cp\u003eAmong 10\u0026ndash;14-year-olds with Lenke 5: right LCEA increased at 2 years (+\u0026thinsp;3.26\u0026deg;; 30.7\u0026rarr;33.96), and both left and right T\u0026ouml;nnis decreased at 2 years (\u0026minus;\u0026thinsp;3.54\u0026deg; and \u0026minus;\u0026thinsp;3.31\u0026deg;, respectively).\u003c/p\u003e\u003cp\u003eAmong 15\u0026ndash;18-year-olds: Lenke 1 showed no significant changes versus baseline after Bonferroni adjustment. Lenke 5 exhibited a slight increase in left T\u0026ouml;nnis at 1 year (+\u0026thinsp;0.95\u0026deg;; 7.65\u0026rarr;8.60).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eKey significant postoperative changes versus preoperative baseline after Bonferroni correction across Age \u0026times; Lenke subgroups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"9\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSubgroup\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eParameter\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTimepoint\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMedian (Pre)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMedian (Time)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eDelta (time\u0026thinsp;\u0026minus;\u0026thinsp;pre)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003en (paired)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e\u003cp\u003eP (adjusted)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e\u003cp\u003eDir\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u0026ndash;14 yrs \u0026amp; Lenke 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eT\u0026ouml;nnis left\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 years\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e10.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e7.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e-2.72\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026darr;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u0026ndash;14 yrs \u0026amp; Lenke 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eT\u0026ouml;nnis right\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e9.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e7.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e-2.25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.026\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026darr;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u0026ndash;14 yrs \u0026amp; Lenke 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 years\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e35.55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e38.82\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.030\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026uarr;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u0026ndash;14 yrs \u0026amp; Lenke 5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eLCEA right\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 years\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e30.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e33.96\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.045\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026uarr;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u0026ndash;14 yrs \u0026amp; Lenke 5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eT\u0026ouml;nnis left\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 years\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e11.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e7.66\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e-3.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.024\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026darr;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u0026ndash;14 yrs \u0026amp; Lenke 5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eT\u0026ouml;nnis right\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 years\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e10.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e7.34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e-3.31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.014\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026darr;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e15\u0026ndash;18 yrs \u0026amp; Lenke 5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eT\u0026ouml;nnis left\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 year\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e7.65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e8.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e0.95\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\u003cp\u003e0.021\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e\u003cp\u003e\u0026uarr;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eData are presented as median [IQR]. P values are Bonferroni-adjusted for three pairwise comparisons (6 months, 1 year, 2 years vs baseline) within each parameter. \u0026ldquo;n (paired)\u0026rdquo; denotes the number of subjects with paired data at the indicated timepoint. Full numerical results are provided in Additional file 1: Tables S1\u0026ndash;S4.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this two-year postoperative cohort, pelvis\u0026ndash;hip remodeling depended on Lenke type and age: younger (10\u0026ndash;14 years) Lenke 1/5 patients showed improved acetabular coverage (lower T\u0026ouml;nnis) and modest sagittal adaptation (higher SS), whereas changes in 15\u0026ndash;18-year-olds were small. These findings support viewing the spine\u0026ndash;pelvis\u0026ndash;hip as an integrated, dynamic unit and considering skeletal maturity in outcome evaluation.\u003c/p\u003e\u003cp\u003eThe decreases in T\u0026ouml;nnis and increases in LCEA in younger adolescents indicate improved acetabular coverage, a favorable morphological signal. In contrast, adult studies have associated longer fusions with increased hip loading and higher risks of joint-space narrowing or osteoarthritis \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. The most plausible explanation is that the biological and geometric plasticity present during growth may offset the adverse hip effects of fusion. This difference underscores that, although the procedure is the same, the direction and magnitude of the hip\u0026ndash;pelvis response vary by age group. Unlike the observation by Si et al. in adult spinal deformity\u0026mdash;where hip pain correlated with pelvic parameters but morphological improvement was not reported \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e\u0026mdash;our participants had open physes; their articular cartilage and periarticular soft tissues are in an active growth phase\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e, conferring greater capacity for adaptive reconstruction. Notably, unlike the pronounced coronal pelvic compensation described in developmental dysplasia cohorts \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e, we did not observe substantial coronal pelvic compensation after correction, suggesting more direct changes in load transmission rather than sacroiliac \u0026lsquo;buffering\u0026rsquo;.\u003c/p\u003e\u003cp\u003eAge and skeletal maturity emerged as key moderators: greater T\u0026ouml;nnis/LCEA and SS changes in 10\u0026ndash;14 years suggest stronger tissue and geometric plasticity, whereas older adolescents showed limited changes, implying that plasticity weakens as physeal closure approaches and the magnitude of remodeling diminishes. These results align with prior studies on the growth-related evolution of pelvic sagittal parameters \u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e and support using developmental stage as an important stratification and decision-making dimension in clinical care. Second, postoperative follow-up of AIS should routinely and systematically monitor pelvic and hip parameters to comprehensively evaluate how surgery affects global load paths. Finally, because adolescents remain in active development, the 2-year follow-up window used in this study may be insufficient to capture the eventual steady state of these adaptive changes; we therefore strongly recommend extending follow-up into skeletal maturity (e.g., 5 and 10 years postoperatively) to determine whether the early favorable changes are sustained and to assess their long-term implications for adult hip health and spinopelvic function.\u003c/p\u003e\n\u003ch3\u003eLimitations\u003c/h3\u003e\n\u003cp\u003eThis retrospective single-center study limits generalizability. The cohort comprised females only; extrapolation to males should be cautious, and sex-by-Lenke interactions merit testing in future work. Inferential analyses focused on Lenke 1/5 due to underpowered subtypes, which may introduce selection bias; conclusions primarily apply to Lenke 1/5 AIS. Standing posture and residual rotation may influence absolute values of LCEA, T\u0026ouml;nnis, and PI/PT/SS despite standardized imaging and sensitivity checks; thus, we emphasize within-subject longitudinal changes over cross-sectional absolutes. Finally, the two-year follow-up captures early adaptation but may not reflect the eventual steady state; longer-term follow-up to skeletal maturity is needed.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003ePelvic and hip parameters remodel within two years after PSIF in AIS, with age- and Lenke-specific patterns. Younger patients\u0026mdash;particularly those aged 10\u0026ndash;14 years with Lenke 1/5\u0026mdash;show improved acetabular coverage and adaptive sagittal changes, whereas older adolescents change little. Postoperative assessment should routinely incorporate pelvis\u0026ndash;hip parameters and account for age and curve type to enable tailored long-term management, with extended follow-up to confirm durability of early improvements.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e: Approved by the Ethics Committee of the Second Affiliated Hospital of Kunming Medical University (FEY-BG-39-3.0); consent was waived for this de-identified retrospective analysis. Ethics approval and consent to participate.\u0026nbsp;All procedures performed on this study were in accordance with the ethical standards of the 1964 Helsinki declaration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e: Not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e: The authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: This study was supported by the External Cooperation Research Project of the Second Affiliated Hospital of Kunming Medical University, Yunnan Province, China (Grant No. 2022dwhz19) and Yunnan Provincial Science and Technology Program (Grant No. 202501AY070001-034\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e: Zhou Anli and Lu Ning wrote the main manuscript text. Zhao Zhi, Li Tao, and Wang Yingsong provided the patient data materials. Cheng Jia, Sun Zhihang, and Shen Xinhe collected the data. Tang Hao and Li Wenjin performed the data analysis. All authors reviewed and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplementary Information\u003c/strong\u003e: Additional file 1: Tables S1\u0026ndash;S4 (complete numeric results for each subgroup and timepoint)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number\u003c/strong\u003e: not applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWeinstein SL, Dolan LA, Cheng JC, et al. Adolescent idiopathic scoliosis. Lancet. 2008;371(9623):1527\u0026ndash;37.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKonieczny MR, Senyurt H, Krauspe R. Epidemiology of adolescent idiopathic scoliosis. J Child Orthop. 2013;7(1):3\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11832-012-0457-4\u003c/span\u003e\u003cspan address=\"10.1007/s11832-012-0457-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTsirikos AI, Mataliotakis G, Bounakis N. Posterior spinal fusion for adolescent idiopathic scoliosis using a convex pedicle screw technique. Bone Joint J. 2017;99\u0026ndash;B(8):1080\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1302/0301-620X.99B8.BJJ-2016-1351.R1\u003c/span\u003e\u003cspan address=\"10.1302/0301-620X.99B8.BJJ-2016-1351.R1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKerboull M. Le retentissement sur le genou des d\u0026eacute;formations inv\u0026eacute;t\u0026eacute;r\u0026eacute;es de la hanche. Conf\u0026eacute;rences d\u0026rsquo;enseignement de la SOFCOT. Paris: Expansion scientifique fran\u0026ccedil;aise (1990): 129\u0026ndash;149.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHamadouche M et al. Total hip arthroplasty for the treatment of ankylosed hips: a five to twenty-one-year follow-up study. JBJS 83.7 (2001): 992\u0026ndash;998.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKerboull M, Hamadouche M, Kerboull L. Total hip arthroplasty for Crowe type IV developmental hip dysplasia: a long-term follow-up study. J Arthroplast. 2001;16(8):170\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQu Y, Tang H, Lu N, Li W, Xu P, Zhou T. Biomechanical changes in the lumbar and hip joint after curved periacetabular osteotomy. J Orthop Surg Res. 2024;19(1):770. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s13018-024-05250-5\u003c/span\u003e\u003cspan address=\"10.1186/s13018-024-05250-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Published 2024 Nov 19.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLonstein JE, Carlson JM. The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg Am. 1984;66(7):1061\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMannava S, Geeslin AG, Frangiamore SJ et al. Comprehensive Clinical Evaluation of Femoroacetabular Impingement: Part 2, Plain Radiography. Arthrosc Tech. 2017;6(5):e2003-e2009. Published 2017 Oct 30. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.eats.2017.06.011\u003c/span\u003e\u003cspan address=\"10.1016/j.eats.2017.06.011\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eClohisy JC, Carlisle JC, Beaul\u0026eacute; PE, et al. A systematic approach to the plain radiographic evaluation of the young adult hip. J Bone Joint Surg Am. 2008;90(4):47\u0026ndash;66. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2106/JBJS.H.00756\u003c/span\u003e\u003cspan address=\"10.2106/JBJS.H.00756\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYu Y, Song K, Wu B, et al. Coronal Compensation Mechanism of Pelvic Obliquity in Patients With Developmental Dysplasia of the Hip. GLOB SPINE J. 2021;13(4):949\u0026ndash;53. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/219256822110107601\u003c/span\u003e\u003cspan address=\"10.1177/219256822110107601\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVialle R, Levassor N, Rillardon L, Templier A, Skalli W, Guigui P. Radiographic analysis of the sagittal alignment and balance of the spine in asymptomatic subjects. J Bone Joint Surg Am. 2005;87(2):260\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2106/JBJS.D.02043\u003c/span\u003e\u003cspan address=\"10.2106/JBJS.D.02043\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMac-Thiong JM, Berthonnaud E, Dimar JR 2nd, Betz RR, Labelle H. Sagittal alignment of the spine and pelvis during growth. Spine (Phila Pa 1976). 2004;29(15):1642\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/01.brs.0000132312.78469.7b\u003c/span\u003e\u003cspan address=\"10.1097/01.brs.0000132312.78469.7b\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLenke LG, Betz RR, Harms J, et al. Adolescent idiopathic scoliosis: a new classification to determine extent of spinal arthrodesis. J Bone Joint Surg Am. 2001;83(8):1169\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSterne JA, White IR, Carlin JB, et al. Multiple imputation for missing data in epidemiological and clinical research: Potential and pitfalls. BMJ. 2009;338:b2393.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUkai T, Katoh H, Yokoyama K, Sato M, Watanabe M. Effect of spinal fusion on joint space narrowing of the hip: comparison among non-fusion, short fusion, and middle or long fusion. J Orthop Traumatol. 2023;24(1):1. Published 2023 Jan 9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s10195-022-00682-3\u003c/span\u003e\u003cspan address=\"10.1186/s10195-022-00682-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKawai T, Shimizu T, Goto K, et al. Number of Levels of Spinal Fusion Associated with the Rate of Joint-Space Narrowing in the Hip. J Bone Joint Surg Am. 2021;103(11):953\u0026ndash;60. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2106/JBJS.20.01578\u003c/span\u003e\u003cspan address=\"10.2106/JBJS.20.01578\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUlusoy İ, Kıvrak A. Lumbosacral fusion increases the risk of hip osteoarthritis. J Orthop Surg Res. 2023;18(1):452. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s13018-023-03932-0\u003c/span\u003e\u003cspan address=\"10.1186/s13018-023-03932-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Published 2023 Jun 24.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSi G, Li T, Liu X, Liu Z, Li W, Yu M. Correlation analysis between postoperative hip pain and spino-pelvic/hip parameters in adult scoliosis patients after long-segment spinal fusion. Eur Spine J. 2020;29(12):2990\u0026ndash;7. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00586-020-06316-8\u003c/span\u003e\u003cspan address=\"10.1007/s00586-020-06316-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChatelain LS, Simon AL, Khalif\u0026eacute; M, Ferrero E. Pediatric spinal alignment and spinal development. N Am Spine Soc J. 2024;20:100548. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.xnsj.2024.100548\u003c/span\u003e\u003cspan address=\"10.1016/j.xnsj.2024.100548\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Published 2024 Aug 13.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"adolescent idiopathic scoliosis, posterior spinal fusion, pelvis, hip, Lenke classification","lastPublishedDoi":"10.21203/rs.3.rs-7782644/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7782644/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eAdolescent idiopathic scoliosis (AIS) correction may influence pelvic sagittal alignment and hip coronal morphology, but growth-stage trajectories remain unclear.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eWe retrospectively included 138 female AIS patients who underwent posterior spinal fusion (PSIF). Standing full-length spine\u0026ndash;pelvis radiographs were obtained preoperatively and at 6 months, 1 year, and 2 years postoperatively. Parameters included Cobb angle, lateral center\u0026ndash;edge angle (LCEA), T\u0026ouml;nnis angle, iliac obliquity (IO), sacral obliquity (SO), and pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Analyses were stratified by age (10\u0026ndash;14 vs 15\u0026ndash;18 years) and Lenke type (1 vs 5). Within-subject comparisons used repeated-measures ANOVA or Friedman tests with Bonferroni-adjusted pairwise tests; between-group tests and correlations used standard parametric/non-parametric procedures.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eAge- and Lenke-specific remodeling patterns were evident. In 10\u0026ndash;14-year-olds with Lenke 1, T\u0026ouml;nnis decreased (right \u0026minus;\u0026thinsp;2.25\u0026deg; at 6 months; left \u0026minus;\u0026thinsp;2.72\u0026deg; at 2 years) and SS increased at 2 years (+\u0026thinsp;3.27\u0026deg;). In 10\u0026ndash;14-year-olds with Lenke 5, right LCEA increased at 2 years (+\u0026thinsp;3.26\u0026deg;) while both T\u0026ouml;nnis angles decreased (\u0026minus;\u0026thinsp;3.54\u0026deg; and \u0026minus;\u0026thinsp;3.31\u0026deg;). Changes were small in 15\u0026ndash;18-year-olds; only Lenke 5 showed a slight increase in left T\u0026ouml;nnis at 1 year (+\u0026thinsp;0.95\u0026deg;).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003ePelvis\u0026ndash;hip parameters remodel within two years after PSIF, with greater improvements in acetabular coverage and sagittal adaptation among younger adolescents (10\u0026ndash;14 years), especially Lenke 1/5, suggesting higher biomechanical plasticity before skeletal maturity. Routine postoperative assessment should incorporate pelvis\u0026ndash;hip parameters with age/Lenke context to inform long-term management.\u003c/p\u003e","manuscriptTitle":"Dynamic remodeling of pelvic sagittal and hip coronal parameters after posterior spinal fusion in adolescent idiopathic scoliosis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-13 08:00:11","doi":"10.21203/rs.3.rs-7782644/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-17T15:15:10+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-08T11:09:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"99372275296596025463891437658455913125","date":"2026-02-28T07:36:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"121916374199185689038557668625310989225","date":"2026-02-27T00:16:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"32192784168796857306076969672167144775","date":"2026-02-26T17:52:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-26T08:10:38+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-25T12:54:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"228945237300333250627961646463002860182","date":"2026-02-23T23:35:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"103962590427129734447372804559209586258","date":"2026-02-23T13:02:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"169037220386500551478400678596025650124","date":"2026-02-23T11:20:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"20643476245678370254890985799069056707","date":"2026-02-23T08:25:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"106270279892000023581461802397516040981","date":"2026-02-06T10:04:37+00:00","index":"hide","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-20T15:24:54+00:00","index":"","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-02T16:35:16+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-11T07:17:04+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-11T07:15:00+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Musculoskeletal Disorders","date":"2025-10-05T03:57:33+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e639fbf3-268d-4980-a585-da58fbce3170","owner":[],"postedDate":"November 13th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-03-17T15:24:42+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-13 08:00:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7782644","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7782644","identity":"rs-7782644","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}