Background The quality of occupational health technical services is directly linked to the protection of workers' health rights and the efficacy of occupational disease prevention and control. However, the industry still faces critical challenges: sporadic instances of institutional non-compliance and persistent irregularities in professional practice continue to undermine overall service performance. Objective To assess the current quality status of occupational health technical services in Zhejiang Province and propose countermeasures for quality improvement, providing a scientific basis for policy optimization and service delivery quality enhancement. Methods A total of 69 occupational health technical service institutions in Zhejiang Province that obtained formal accreditation as of April 30, 2024, were sampled, including 3 public institutions and 66 private institutions (comprising 3 formerly Class-A, 28 formerly Class-B, 11 formerly Class-C, and 24 newly certified institutions). Following the Technical Protocol for Quality Monitoring of Occupational Health Technical Service in Zhejiang Province and the Technical Protocol for Proficiency Testing of Occupational Health Detection in Zhejiang Province, a quality assessment task force comprising national and provincial experts was established. Evaluation was conducted across four dimensions: qualification maintenance and compliance, standardization of technical services, authenticity of technical services, and proficiency testing, utilizing a combination of document review, on-site inspections, and technical skill assessments. Results The occupational health technical service institutions in Zhejiang Province were predominantly private entities (82.5%), with significant disparities in overall service quality. The pass rates for qualification maintenance and compliance, technical service standardization, technical service authenticity, and the excellence rate for laboratory proficiency testing were 81.5%, 80.7%, 97.3%, and 90.4%, respectively. Regarding qualification maintenance, the pass rates for "environmental conditions" (49.8%, 56.7%) and "instrumentation and equipment" (58.2%、65.6%) were significantly lower for formerly Class-C and newly certified institutions compared to other categories. In terms of technical standardization, "standardized on-site inspections" recorded the lowest pass rate (67.4%), with newly certified institutions at only 48.0%. Regarding technical service authenticity, formerly Class-C institutions exhibited issues such as missing raw chromatograms for blank samples (85.7% pass rate). In laboratory proficiency testing, public and formerly Class-A institutions achieved 100% excellence rates, but the performance of formerly Class-C and newly certified institutions was comparatively weak; specifically, the failure rate for organic analysis in formerly Class-C institutions reached 20%; the failure rate for dust testing items in newly certified institutions was 10.3%. Conclusion The overall quality of occupational health technical services in Zhejiang Province still requires significant improvement, particularly in basic institutional conditions, the standardization of on-site inspections, and laboratory proficiency in organic and dust analysis. Formerly Class-C and newly certified institutions should be the primary focus of quality management efforts. Differentiated regulatory strategies are recommended, alongside strengthening interim and ex-post supervision to gradually enhance the quality of occupational health technical services across all institutions.

Objective To investigate the effects of combined exposure to benzene series, dust and noise on occupational high-frequency hearing loss (HFHL) in the electronics manufacturing industry. Methods A total of 740 employees from an electronic manufacturing enterprise were selected as the study subjects. According to the detection of occupational hazard factors, they were divided into noise group, noise benzene group, and noise dust group, with 325, 167, and 248 people, respectively. Occupational health examinations were conducted on the study participants to analyze their HFHL detection status and influencing factors. Results Among all participants (n=740), 456 (61.62%) were male, 284 (38.38%) were female, and 123 (15.62%) were detected with HFHL. The detection rate of HFHL increased with age and length of service (P<0.01). According to the exposure factor grouping, the detection rates of HFHL in the noise group, noise benzene group, and noise dust group were 12.00%, 19.16%, and 20.97%, respectively (P<0.05). Multivariate logistic regression analysis showed that workers aged ≥ 40 years, with 10-20 years of work experience, ≥ 20 years of work experience, exposure to noise and benzene series, and exposure to noise and dust had an increased risk of developing HFHL to 1.734, 1.923, 3.071, 1.706, and 1.527, respectively (P<0.05). Conclusion Combined exposure to noise and benzene series, combined exposure to noise and dust, as well as age and extended length of service may increase the risk of HFHL among workers.

Background/Aims: Liver transplantation (LT) following total hepatectomy is a life-saving treatment for hepatocellular carcinoma (HCC). The HCC recurrence after LT hinders the effectiveness of the procedure. The objective of this study is to develop a pre-operative risk stratification model based on a liquid biopsy. Methods: We conducted a comprehensive multi-omics study of 260 HCC patients from three centers, including clinical data, low-coverage whole-genome sequencing of cell-free DNA (cfDNA) from plasma, as well as whole-exome, single-nucleus RNA, and spatial transcriptomics from matched tumor and non-tumor tissues. Results: We identified cfDNA-derived copy number alteration (CNA) signatures associated with post-transplant recurrence. By integrating cfDNA-derived CNA profiles with single-cell transcriptomic data, we traced recurrence-associated cfDNA to a distinct subpopulation of malignant cells within the primary tumor. These cells were embedded in a pro-metastatic microenvironment of specialized endothelial subtypes and cancer-associated fibroblasts. Notably, most recurrence-associated lesions were detectable in cfDNA prior to liver transplantation (LT). Building on these insights, we developed the ZJU Criteria based on CNA fragments and tumor markers, a pre-LT risk prediction tool that integrates conventional clinical factors with cfDNA-derived CNA signatures, and validated it using internal and independent external cohorts. Conclusion Our findings suggest that post-transplant recurrence commonly originates from advanced subclones that emerge late during tumor evolution. The ZJU Criteria provides an accurate, non-invasive strategy that significantly improves pre-LT risk stratification and clinical decision-making for patients with HCC.

Objective We reviewed and analyzed the epidemiological data of 83 imported dengue fever cases reported in Fengtai District, Beijing, from 2007 to 2025, to delineate their epidemiological characteristics and guide the dengue fever prevention and control strategy in the future. Methods Data on dengue fever cases in Fengtai District from 2007 to 2025 were collected to identify the epidemic factors and characteristics using descriptive epidemiological method. Results All 83 dengue fever cases reported in this region over the past two decades have been imported from abroad or other domestic areas, with Southeast Asian countries being identified as the primary source of imported infections, accounting for 42 cases (50.60%), followed by 15 cases (18.07%) from Chinese provinces other than Beijing. The remaining import sources included 13 cases from South Asia,8 from African countries, and each from Oceania, South America, and Europe. Disease onset was found concentrated between May and November. The sex ratio (male-to-female) is 1.59:1. The age of onset ranged from 14 to 61 years old, with a median age of 36. The largest proportion of cases was observed among cadres and office workers (31 cases, 37.35%), followed by businessmen (13 cases, 15.67%), and householders or the unemployed (10 cases,12.05%). Travel visit was identified as the primary reason for their exposure history. Conclusions All dengue fever cases reported in Fengtai from 2007 to 2025 were imported, with an increasing trend of imported cases in Beijing originating from other Chinese provinces. It is essential to strengthen health education for foreign travelers and returning residents, enhance clinical diagnosis and treatment training for medical personnel, eliminate mosquito breeding sites, and reduce mosquito density through active patriotic health campaigns.

Objective:To explore a selective resection strategy for combined lumbosacral hemivertebra (LSHV) and thoracolumbar hemivertebra/lumbar hemivertebra (TLHV/LHV) double-balanced hemivertebra deformities.Methods:A retrospective analysis was conducted on 21 patients aged over 10 years with lumbosacral and thoracolumbar or lumbar combined hemimetameric segmental shift (HMMS) deformities who underwent surgery at Nanjing Drum Tower Hospital between May 2009 and October 2022. The cohort included 7 males and 14 females, with a mean surgical age of 21.5±10.9 years (range: 12-55 years) and a mean follow-up duration of 32.8±15.9 months (range: 24-74 months). Patients were divided into two groups based on preoperative coronal balance: the balanced group (Type A) and the unbalanced group (Type C). Radiographic parameters, including the major Cobb angle, lumbosacral take-off angle, kyphotic angle, coronal balance distance (CBD), and the deviation of the upper instrumented vertebra (UIV), were measured preoperatively, postoperatively, and at the final follow-up. Surgical complications were also recorded.Results:Of the 21 patients, 11 were classified as preoperatively balanced, and 10 as unbalanced. The deformity angular ratio of thoracolumbar to lumbosacral curves was significantly higher in the balanced group than in the unbalanced group (0.9±0.3 vs. 0.6±0.2; t=2.143, P=0.045). The preoperative main curve Cobb angles in the balanced and imbalanced groups were 71.3°±22.3° and 58.6°±8.2°, respectively. One week postoperatively, these angles were reduced to 38.4°±17.6° and 31.3°±5.6°, and were maintained at 40.0°±18.1° and 32.6°±5.6° at the final follow-up, all differences were statistically significant ( P<0.05). The preoperative lumbosacral take-off angles were 37.5°±9.1° in the balanced group and 36.7°±7.7° in the imbalanced group, which decreased to 18.4°±9.4° and 19.2°±5.5° at 1 week postoperatively, and remained at 19.4°±10.1° and 19.6°±5.8° at the final follow-up. These changes were also statistically significant ( P<0.05). In the balanced group, the UIV tilt angle, the CBD and the deviation of the UIV, were all significantly reduced compared to preoperative values ( P<0.05). Among the 21 patients, LSHV resection was performed in 15 cases, and TLHV/LHV resection was performed in 7 cases. Among the 15 patients with kyphosis, TLHV/LHV resection was performed in 6 cases. In the balanced group, 9 patients maintained type A postoperatively, including 4 patients with LSHV resection, 2 with TLHV/LHV resection, 2 with both LSHV and TLHV/LHV resection, 1 without resection of both hemivertebra. Two patients in the balanced group who underwent TLHV/LHV resection experienced postoperative deterioration to type C. In the unbalanced group, 8 cases with LSHV resection improved to type A, while 1 case with LSHV resection and 1 case with neither resection maintained C-type. In the LSHV resection group, CBD improved from 29.8±15.2 mm to 13.9±5.7 mm postoperatively and remained stable at 14.6±8.6 mm at final follow-up. Only 1 patient in this group experienced worsened coronal imbalance. In contrast, in the non-LSHV resection group, CBD worsened from 17.2 ± 8.7 mm to 19.7±12.1 mm postoperatively, progressing further to 20.5±13.0 mm at follow-up. Three patients in this group had worsening coronal imbalance, and 2 required revision surgery. Reported complications included 3 cases of internal fixation fracture, 1 case of proximal junctional kyphosis, and 1 case of acute incision infection. Conclusions:Effective resection of lumbosacral hemivertebrae is the preferred selective strategy, particularly for patients with preoperative coronal imbalance, as it significantly reduces the risk of worsening coronal imbalance and internal fixation-related complications. However, selective resection involving only TLHV or LHV without addressing LSHV in preoperatively balanced patients may increase the risk of postoperative coronal imbalance.

Objective:To investigate the effect of anterior and posterior selective fusion strategy on evolution of coronal pattern in patients with Lenke 5C adolescent idiopathic scoliosis (AIS) and whether upper end vertebra (UEV)-1 strategy in anterior surgery would have an effect on postoperative coronal balance.Methods:A total of 108 Lenke 5C AIS patients with at least 2 years follow-up who underwent anterior or posterior selective thoracolumbar fusion surgery from January 2005 to December 2020 were enrolled, with 51 patients in the anterior group and 57 patients in the posterior group. The patients were categorized into three groups (type A, C 7PL-CSVL<20 mm; type B, C 7PL-CSVL ≥20 mm with C 7PL toward the concave side of the main curve; and type C, C 7PL-CSVL≥20 mm with C 7PL toward the convex side of the main curve) to investigate the evolution of coronal balance of each preoperative coronal pattern at the anterior and posterior groups. Parameters such as thoracolumbar Cobb angle, rate of coronal imbalance, and SRS-22 score were recorded at preoperative, 1 week postoperatively, and final follow-up in both groups. Results:The differences of basic date between the two groups were not statistically significant except for the fusion level (5.2±0.7 vs. 5.6±0.9, t=2.497, P=0.014). In the anterior group, a total of 27 patients with preoperative type A, 23 patients with preoperative type A maintained type A at the 1 week postoperatively, and 2 of them were converted to type C at the final follow-up. Four patients with preoperative type A converted to type C at the 1 week postoperatively, and all of them returned to type A at the final follow-up. A total of 23 patients with preoperative type C, four patients with preoperative type C maintained type C at the 1 week postoperatively, and one of them maintained type C at the final follow-up. Nineteen patients with preoperative type C converted to type A at the 1 week postoperatively, and all of them maintained type A at the final follow-up. In the posterior group, a total of 26 patients with preoperative type A, 22 patients with preoperative type A maintained type A at the 1 week postoperatively, and only 2 of these patients converted to type C at the final follow-up. Four of the preoperative type A patients converted to type C at the 1 week postoperatively, and all of them returned to type A at the final follow-up. A total of 29 patients with preoperative type C, thirteen patients with preoperative type C maintained type C at the 1 week postoperatively, and 7 of them maintained type C at the last follow-up. Sixteen patients with preoperative type C converted to type A at the 1 week postoperatively, of whom two converted to type C at the final follow-up. For patients with preoperative type C the rate of coronal imbalance was significantly lower in the anterior group than in the posterior group both in the immediate postoperative period (17% vs. 45%, P<0.05) and at the final follow-up (4% vs. 31%, P=0.038). The rate of coronal imbalance at final follow-up was significantly lower in the UEV-1 group than in the UEV group in the posterior approach (3% vs. 38%, P<0.05), and there was no difference between the two groups in the anterior approach. There were no significant differences in radiographic parameters and SRS-22 scores between the two groups, except for the thoracic Cobb angle at the final follow-up, which was greater in the anterior group than in the posterior group at the final follow-up (19.5±7.3 vs.16.4±5.6, t=2.427, P=0.017). Multivariate logistic regression analysis revealed that anterior surgery and Risser were risk factors for postoperative CIB of preoperative type C ( OR=21.138, P=0.030 and OR=0.406, P=0.048 respectively). Conclusion:For patients with preoperative type A, both anterior and posterior procedures lead to a satisfactory reconstruction of coronal balance. In patients with preoperative type C, anterior surgery acquire a better reconstruction of coronal balance. The strategy of proximal UEV-1 was similar to the strategy of UEV in terms of restoring coronary balance in anterior approach and it was unable to lower the rate of postoperative coronal imbalance. In contrast, UEV-1 strategy in posterior surgery was effective in reducing the rate of postoperative coronal imbalance.

Objective:To analyze the selection of internal fixation methods, surgical outcomes, and complications in patients with Neurofibromatosis Type 1 (NF1) accompanied by dystrophic lumbosacral deformities, and to evaluate the indications for pelvic fixation.Methods:A retrospective analysis was conducted on 21 patients with NF1 and associated dystrophic lumbosacral malformations (L 4 to sacrum) who underwent spinal deformity correction surgery at Nanjing Drum Tower Hospital from January 2009 to November 2022. The cohort included 11 males and 10 females, with a mean surgical age of 15.4±4.7 years (range, 7-24 years). Patients were divided into two groups based on whether pelvic fixation was performed: 10 patients in the non-pelvic fixation group (NP group) and 11 in the pelvic fixation group (P group), where fixation involved second sacral alar-iliac (S 2AI) screws or iliac screws. Radiographic parameters, including the Cobb angle of the lumbosacral fractional curve, main curve, and focal kyphosis, were compared preoperatively, postoperatively, and at the last follow-up. Results:The NP group had a significantly lower mean age (13.2±4.9 years) compared to the P group (17.5±3.5 years; t=2.287, P=0.034). Spinal instability (rotational subluxation or spondylolisthesis) due to dystrophic changes was observed in 2 patients in the NP group and 8 in the P group, a statistically significant difference (χ 2=5.838, P=0.030). In the P group, five patients underwent unilateral fixation and six underwent bilateral fixation. Implant types included 2 cases with iliac screws, 1 case with iliac screws plus S 2AI, and 8 cases with S 2AI screws alone. The utilization rate of hooks was significantly higher in the NP group (12.6%±11.5%) compared to the P group (3.5%±6.9%; t=2.230, P=0.038). The preoperative Cobb angle of the lumbosacral fractional curve was significantly smaller in the NP group (13.8°±9.0°) than in the P group (25.5°±13.9°; t=2.228, P=0.039). Postoperatively, the angles were corrected to 6.3°±6.1° and 6.4°±5.3°, respectively ( t=0.901, P=0.969), with correction rates of 57.3%±13.6% and 74.1%±17.8% ( t=2.369, P=0.029). At final follow-up, the angles remained stable (6.6°±6.6° vs. 6.3°±4.8°; t=0.116, P=0.909). For the main curve, preoperative Cobb angles were 52.5°±15.1° (NP) and 61.1°±16.9° (P; t=1.200, P=0.246), corrected to 31.3°±13.8° and 28.0°±8.4°, respectively ( t=0.646, P=0.526). Correction rates were 41.3%±13.0% in the NP group and 53.2%±11.6% in the P group ( t=2.206, P=0.037). At the final follow-up, these values were 32.4°±14.2° and 31.7°±10.3° ( t=0.133, P=0.896). Focal kyphosis, seen in 9 patients, was corrected from 19.7°±10.9° preoperatively to -13.6°±9.5° postoperatively, and remained at -14.1°±9.6° at the final follow-up ( F=33.547, P<0.001). Multi-rod systems were used in 6 cases (NP group) and 7 cases (P group), with no significant difference (χ 2=0.153, P=0.926). Two patients in the NP group developed coronal decompensation three years postoperatively, and one required revision surgery. In the P group, rod breakage occurred in 3 patients, two of whom underwent revision. Conclusions:Dystrophic rotational subluxation or spondylolisthesis of the lumbosacral spine is a primary indication for pelvic fixation in patients with NF1-associated deformities. However, complications related to internal fixation remain common. The combined use of a multi-rod screw-hook hybrid system, particularly when extending across the lumbosacral region, may reduce the risk of instrumentation failure.

Objective:To evaluate the relationship between postoperative changes in femoral head coverage (FHC) after S 2-Alar-Iliac (S 2AI) screw fixation and the development of sagittal imbalance during follow-up in patients with adult spinal deformity (ASD), providing insights for clinical assessment and treatment strategies. Methods:A consecutive cohort of 98 ASD patients who underwent S2AI fixation between September 2019 and September 2021 was retrospectively analyzed. Patients were divided into two groups based on changes in femoral head coverage (ΔFHC): the FHC-C group (upper quartile ΔFHC, 25 cases) and the FHC-NC group (lower quartile ΔFHC, 24 cases). Additionally, patients were classified into proximal junctional kyphosis (PJK) and non-PJK groups based on their clinical outcomes at the last follow-up. Standing full-spine anteroposterior and lateral X-rays were taken preoperatively, postoperatively, and at the two-year follow-up to measure and document the following spinal parameters: Cobb angle, proximal lumbar lordosis (PLL), distal lumbar lordosis (DLL), lumbar lordosis (LL), lordosis distribution index (LDI), sagittal vertical axis (SVA), coronal balance distance (CBD), thoracic kyphosis (TK), T 1 pelvic angle (T 1PA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), PI-LL, and proximal junctional angle (PJA). Parameters related to hip joint coverage included: femoral head coverage (FHC), lateral center-edge angle (LCE angle), acetabular index (AI), Sharp angle, and extrusion index (EI). Comparisons of radiographic indicators between the two groups were performed at preoperative, postoperative, and final follow-up assessments. The visual analogue scale (VAS) was used to evaluate the hip pain and back pain. Results:At final follow-up, the incidence of PJK was significantly higher in the FHC-NC group [37.5% (9/24)] compared to the FHC-C group [16.0% (4/25)] (χ 2=3.952, P=0.042). Moreover, the increase in sagittal vertical axis (ΔSVA) was significantly greater in the FHC-NC group (35.9±44.7 mm vs. 14.6±31.8 mm, t=2.216, P=0.031). Patients with PJK had significantly higher preoperative T 1PA (36.8°±10.8° vs. 31.9°±18.4°, t=2.150, P=0.034) and lower immediate postoperative ΔFHC (1.7%±1.5% vs. 3.3%±2.5%, t=2.987, P=0.004), as well as lower changes in lateral center-edge angle during follow-up (0.3°±3.0° vs. 1.1°±8.9°, t=2.334, P=0.022). Pearson correlation analysis revealed significant negative correlations between postoperative ΔFHC and both ΔSVA ( r=-0.374, P=0.008) and proximal junctional angle changes (ΔPJA, r=-0.429, P=0.006). Additionally, increases in VAS leg pain scores correlated negatively with immediate postoperative FHC ( r=-0.314, P=0.025) and ΔFHC ( r=-0.298, P=0.031). Logistic regression indicated that immediate postoperative ΔFHC was a protective factor against PJK [ OR=0.722, 95% CI (0.541, 0.963), P=0.009), with a ROC-determined optimal ΔFHC cut-off of 3.90% (AUC=0.723, Youden index=0.847). Conclusions:Postoperative evaluation of femoral head coverage is clinically important for ASD patients undergoing S2AI screw fixation. A pre-to-post ΔFHC below 3.90% may indicate reduced hip compensation capacity, increasing risks for hip pain, sagittal imbalance progression, and PJK postoperatively.

Objective:To predict mechanical complications (MC) following spinal deformity surgery for adult spine deformity (ASD) using machine learning models, identify key risk factors, and develop a visualizable tool for individualized risk assessment.Methods:Clinical and radiological data from 525 patients with ASD who underwent surgery in our hospital between January 2017 and December 2021 were collected. Patients were randomly assigned to a training set (70%) and a test set (30%) for model development. The cohort included 88 males and 437 females, with a mean age of 42.2±18.1 years. Variables included demographic data, comorbidities, local and systemic radiological parameters, paraspinal muscle fat infiltration (FI), and vertebral bone quality (VBQ) scores. Multiple machine learning algorithms: Random Forest (RF), Gaussian Naive Bayes (GNB), Light GBM, Support Vector Machine (SVM), XGBoost (XGB), and Logistic Regression (LR) were trained and evaluated. Model performance was compared using the receiver operating characteristic curve (ROC) and precision-recall curve (PRC). SHAP (Shapley Additive Explanations) was used to rank risk factors, while LIME (Local Interpretable Model-Agnostic Explanations) was applied to visualize MC risk in individual cases.Results:Of the 525 patients, 135 (25.7%) developed postoperative MC. Among these, 80 (59.3%) experienced proximal junction kyphosis or failure (PJK/PJF), 7 (5.2%) had distal junction kyphosis or failure (DJK/DJF), 28 (20.7%) sustained rod fractures, and 29 (21.5%) showed significant loss of correction. In the validation cohort, the RF model achieved the highest area under the curve (AUC=0.80), followed by GNB (0.77), XGB (0.76), LR (0.74), LightGBM (0.73), and SVM (0.66). The RF model also demonstrated the best PRC value (0.58), highest sensitivity (0.65), and lowest Brier score (0.20). GNB, Light GBM, and LR models achieved the highest accuracy (0.78 each), while LightGBM exhibited the highest specificity (0.93). SHAP analysis identified higher preoperative VBQ scores, larger T 1 pelvic angle (TPA), and higher paraspinal muscle FI as the main risk factors for MC. Based on the RF model, a LIME-based tool was successfully constructed for individualized MC risk estimation. Conclusion:The RF model demonstrated the best overall predictive performance for MC. A machine learning-based prediction model has the potential to provide valuable guidance for surgical decision-making in ASD patients.

Objective:To compare the incidence of instrumentation-related complications and health-related quality of life following pelvic fixation using iliac screws (IS) or second sacral alar-iliac (S 2AI) screws in adult spinal deformity (ASD). Methods:A retrospective cohort study was conducted on 108 ASD patients who underwent posterior corrective fusion and fixation extending to the pelvis at Nanjing Drum Tower Hospital between September 2010 and April 2021. According to the type of pelvic fixation, patients were divided into an IS group ( n=34; 12 males, 22 females; mean age 53.7±11.1 years, range 28-73 years) and an S 2AI group ( n=74; 23 males, 51 females; mean age 52.8±8.6 years, range 27-72 years). Pre- and post- operative standing anteroposterior and lateral radiographs were evaluated for Cobb angle, coronal balance distance (CBD), thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). At 2 years postoperatively, health-related quality of life were assessed using the Scoliosis Research Society-22 questionnaire (SRS-22), Oswestry disability index (ODI), and visual analogue scale (VAS) for pain. Instrumentation failure related to pelvic fixation during follow-up was recorded. Results:All patients completed follow-up. Mean follow-up duration was 28.5±3.6 months (range 24-37 months) in the IS group and 28.1±4.3 months (range 24-43 months) in the S 2AI group. Postoperatively, both groups showed significant improvement in Cobb angle, CBD, TK, LL, SVA, PT, and SS compared to baseline ( P<0.05), whereas PI remained unchanged ( t=0.664, P=0.509; t=1.227, P=0.222). Preoperative PT was greater in the IS group than in the S 2AI group (33.6°±8.7° vs. 29.3°±9.6°, t=2.228, P=0.028). No significant intergroup differences were observed in any other pre- or post- operative radiographic parameters ( P>0.05). Pelvic fixation failure occurred in 31 patients (28.7%, 31/108). Patients with fixation failure had a longer fusion segment extension than those without failure (12.0±2.8 vs. 10.8±2.4 segments; t=2.256, P=0.026). In the IS group, complications comprised 3 cases of screw loosening (8.8%), 2 of screw breakage (5.9%), and 4 of rod fracture within the pelvic region (11.8%), including 1 case with concurrent screw and rod failure. In the S 2AI group, there were 21 cases of screw loosening (28.4%) and 2 of screw breakage (2.7%). Screw loosening was less frequent in the IS group than in the S 2AI group (χ 2=5.154, P=0.023), whereas pelvic rod fracture was more common in the IS group (χ 2=9.041, P=0.003). Screw breakage rates did not differ significantly ( P>0.05). Mean VAS, ODI, and SRS-22 scores in the IS group were 3.2±2.4, 24.9%±18.8%, and 3.2±0.8, respectively; corresponding to 2.5±1.8, 18.9%±10.9%, and 3.3±0.6 in the S 2AI group. ODI was significantly higher in the IS group ( t=2.062, P=0.042), whereas VAS and SRS-22 were comparable ( P>0.05). Among S 2AI patients, VAS and ODI scores did not differ significantly between those with and without screw loosening ( P>0.05). Conclusions:The post-operative incidence of pelvic fixation failure following ASD surgery reached 28.7%. The predominant failure mode with S 2AI was screw loosening, whereas IS was more frequently complicated by rod fracture. Early postoperative health-related quality of life was superior with S 2AI screws compared with iliac screws.