Objective: To assess the effectiveness of vertebral cement augmentation (VCA) at upper instrumented vertebra (UIV) and UIV+1 in preventing proximal junction complications in correction surgery for adult spinal deformity patients. Methods: A literature search was conducted on Web of Science, PubMed, and Cochrane Library databases for comparative studies published before December 30th, 2024. Two reviewers independently screened eligible articles based on the inclusion and exclusion criteria, assessed study quality with Newcastle-Ottawa scale, and extracted data like study characteristics, surgical details, primary and secondary outcomes. Data analysis was performed using Review Manager 5.4 and Stata software. Results: Of all 513 papers screened, a meta-analysis was conducted on 7 articles, which included 333 cases in the VCA group and 827 cases in the control group. Patients in the VCA group had significantly older age and lower T score than patients in the control group. Although there was no statistically significant difference in the incidence of proximal junctional failure between the 2 groups, the results of the meta-analysis showed that the incidence of proximal junctional failure and the need for revision surgery were reduced by 36% and 71%, respectively, in the VCA group. One study reported 2 clinically silent pulmonary cement embolism and 1 patient requiring surgical decompression for cement leak into the spinal canal. Conclusion This meta-analysis supported the use of VCA in corrective surgery for spinal deformities patients, especially in patients with advanced age and osteoporosis.

Objective: To assess the effectiveness of vertebral cement augmentation (VCA) at upper instrumented vertebra (UIV) and UIV+1 in preventing proximal junction complications in correction surgery for adult spinal deformity patients. Methods: A literature search was conducted on Web of Science, PubMed, and Cochrane Library databases for comparative studies published before December 30th, 2024. Two reviewers independently screened eligible articles based on the inclusion and exclusion criteria, assessed study quality with Newcastle-Ottawa scale, and extracted data like study characteristics, surgical details, primary and secondary outcomes. Data analysis was performed using Review Manager 5.4 and Stata software. Results: Of all 513 papers screened, a meta-analysis was conducted on 7 articles, which included 333 cases in the VCA group and 827 cases in the control group. Patients in the VCA group had significantly older age and lower T score than patients in the control group. Although there was no statistically significant difference in the incidence of proximal junctional failure between the 2 groups, the results of the meta-analysis showed that the incidence of proximal junctional failure and the need for revision surgery were reduced by 36% and 71%, respectively, in the VCA group. One study reported 2 clinically silent pulmonary cement embolism and 1 patient requiring surgical decompression for cement leak into the spinal canal. Conclusion This meta-analysis supported the use of VCA in corrective surgery for spinal deformities patients, especially in patients with advanced age and osteoporosis.

Objective: To assess the effectiveness of vertebral cement augmentation (VCA) at upper instrumented vertebra (UIV) and UIV+1 in preventing proximal junction complications in correction surgery for adult spinal deformity patients. Methods: A literature search was conducted on Web of Science, PubMed, and Cochrane Library databases for comparative studies published before December 30th, 2024. Two reviewers independently screened eligible articles based on the inclusion and exclusion criteria, assessed study quality with Newcastle-Ottawa scale, and extracted data like study characteristics, surgical details, primary and secondary outcomes. Data analysis was performed using Review Manager 5.4 and Stata software. Results: Of all 513 papers screened, a meta-analysis was conducted on 7 articles, which included 333 cases in the VCA group and 827 cases in the control group. Patients in the VCA group had significantly older age and lower T score than patients in the control group. Although there was no statistically significant difference in the incidence of proximal junctional failure between the 2 groups, the results of the meta-analysis showed that the incidence of proximal junctional failure and the need for revision surgery were reduced by 36% and 71%, respectively, in the VCA group. One study reported 2 clinically silent pulmonary cement embolism and 1 patient requiring surgical decompression for cement leak into the spinal canal. Conclusion This meta-analysis supported the use of VCA in corrective surgery for spinal deformities patients, especially in patients with advanced age and osteoporosis.

Objective: To assess the effectiveness of vertebral cement augmentation (VCA) at upper instrumented vertebra (UIV) and UIV+1 in preventing proximal junction complications in correction surgery for adult spinal deformity patients. Methods: A literature search was conducted on Web of Science, PubMed, and Cochrane Library databases for comparative studies published before December 30th, 2024. Two reviewers independently screened eligible articles based on the inclusion and exclusion criteria, assessed study quality with Newcastle-Ottawa scale, and extracted data like study characteristics, surgical details, primary and secondary outcomes. Data analysis was performed using Review Manager 5.4 and Stata software. Results: Of all 513 papers screened, a meta-analysis was conducted on 7 articles, which included 333 cases in the VCA group and 827 cases in the control group. Patients in the VCA group had significantly older age and lower T score than patients in the control group. Although there was no statistically significant difference in the incidence of proximal junctional failure between the 2 groups, the results of the meta-analysis showed that the incidence of proximal junctional failure and the need for revision surgery were reduced by 36% and 71%, respectively, in the VCA group. One study reported 2 clinically silent pulmonary cement embolism and 1 patient requiring surgical decompression for cement leak into the spinal canal. Conclusion This meta-analysis supported the use of VCA in corrective surgery for spinal deformities patients, especially in patients with advanced age and osteoporosis.

Objective: To assess the effectiveness of vertebral cement augmentation (VCA) at upper instrumented vertebra (UIV) and UIV+1 in preventing proximal junction complications in correction surgery for adult spinal deformity patients. Methods: A literature search was conducted on Web of Science, PubMed, and Cochrane Library databases for comparative studies published before December 30th, 2024. Two reviewers independently screened eligible articles based on the inclusion and exclusion criteria, assessed study quality with Newcastle-Ottawa scale, and extracted data like study characteristics, surgical details, primary and secondary outcomes. Data analysis was performed using Review Manager 5.4 and Stata software. Results: Of all 513 papers screened, a meta-analysis was conducted on 7 articles, which included 333 cases in the VCA group and 827 cases in the control group. Patients in the VCA group had significantly older age and lower T score than patients in the control group. Although there was no statistically significant difference in the incidence of proximal junctional failure between the 2 groups, the results of the meta-analysis showed that the incidence of proximal junctional failure and the need for revision surgery were reduced by 36% and 71%, respectively, in the VCA group. One study reported 2 clinically silent pulmonary cement embolism and 1 patient requiring surgical decompression for cement leak into the spinal canal. Conclusion This meta-analysis supported the use of VCA in corrective surgery for spinal deformities patients, especially in patients with advanced age and osteoporosis.

Objective:To develop a set of lowest instrumented vertebra (LIV) selection criteria for adolescent idiopathic scoliosis (AIS) with Lenke 1A curves named as "Gulou Rule", and compared with the traditional "last substantially touching vertebra (LSTV) Rule".Methods:Based on our previous retrospective studies about LIV selection, as well as our clinical experience, the key parameters associated with LIV selection were found out and quantified to form the "Gulou Rule". A prospective consecutive collection of 189 Lenke 1A cases (male 29 cases, female 160 cases) who underwent posterior spinal fusion surgery in our clinic from January 2021 to January 2022 were recruited, with an average age of 14.9±2.8 (range 10-18) years old. They were divided into 2 groups according to the enrollment number (odd or even number). Patients with odd numbers were guided by the "LSTV Rule",while those with even numbers followed the "Gulou Rule" for the selection of LIV. The duration of follow-up was at least two years. Radiographical parameters were measured preoperatively, immediately postoperatively, and at the final follow-up, including numbers of fused segments, Cobb angle of proximal thoracic curve, main thoracic curve and lumbar curve, correction rate, coronal and sagittal balance parameters. The incidence of distal adding-on at the last follow-up was recorded.Results:The "Gulou Rule" was defined as follows: when Risser ≥3, main curve length ≤8 segments, one level proximal to LSTV (LSTV-1) rotation ≤ I degree, LSTV-1 deviation from the CSVL <20 mm, preoperative coronal balance <10 mm, and the intervertebral disc between LSTV-1 and LSTV opens bidirectionally on bending films, the LIV can be selected as LSTV-1; if these conditions are not met, LIV should be selected as LSTV. At last, 120 patients (male 21 cases, female 99 cases) were enrolled in the study with at least a 2-year follow-up, with an average age of 15.1±2.4 (range 10-18) years old. Each group had 60 patients, and the average duration of follow-up was 31.0±5.4 months for the "LSTV Rule" group and 30.8±5.1 months for the "Gulou Rule" group. The LIV in the "Gulou Rule" group was on average at the T 12 and L 1 level, where as in the "LSTV Rule" group, it was at the L 1 and L 2 level ( P=0.004). The "LSTV Rule" group had an average fused segments of 10.5±1.7, while the "Gulou Rule" group was significantly lower with 9.7±1.5 segments ( t=2.760, P=0.003). At the last follow-up, the main curve correction rates were 74.8%±10.5% and 73.2%±12.3%, respectively, with no significant difference ( t=0.779, P=0.219). The incidence of distal adding-on phenomenon was 15% in the "LSTV Rule" group and 17% in the "Gulou Rule" group, with no significant difference between the two groups (χ 2=0.063, P=0.803). Conclusion:For Lenke 1A AIS patients, both the "Gulou Rule" and the "LSTV Rule" for guiding LIV selection can achieve satisfactory correction outcomes. Choosing LIV based on the "Gulou Rule" allows for the preservation of distal fusion segments and demonstrates better clinical applicability.

Objective:To investigate the risk factors for severe distal curve progression after posterior hemivertebra (HV) resection and short-segment fixation in patients with congenital cervicothoracic scoliosis (CTS), and to analyze the surgical revision strategy.Methods:Imaging and clinical data of patients who underwent posterior HV resection and short-segment fixation for CTS between August 2012 and August 2021 at Nanjing Drum Tower Hospital were retrospectively analyzed. A total of 55 patients were recruited, including 27 females and 28 males with an average age of 8.5±3.6 years (range 3-15 years) at surgery and an average Risser grade of 0.7±1.4 (range 0-4). The number of fused segments averaged 6.9±1.6 (range 4-10), and the mean follow-up was 38.7±18.9 months (range 9-94 months). According to the severity of distal curve progression, the recruited patients were divided into three groups: non-progression group (NPG), mild progression group (MPG), and severe progression group (SPG). The latter two groups were collectively called the progression group (PG). The cervicothoracic Cobb angle, T1 tilt angle, coronal balance distance (CBD), neck tilt angle, clavicular angle, head tilt angle, head shift, and upper (UIV) and lower instrument vertebra (LIV) tilt angle on the standing whole spine X-ray were measured before and after surgery and at the last follow-up. The correction rate of the Cobb angle in the osteotomy area was measured and calculated on CT three-dimensional reconstruction, and the proportion of patients with Klippel-Feil syndrome (KFS) was recorded. Statistical analysis was conducted on the various parameters between the two groups. For factors with statistical significance in the single-factor analysis, binary logistic regression analysis was performed to identify the high-risk factors for distal curve progression.Results:There were 38 cases in the NPG, 11 in the MPG, and 6 in the SPG. Compared to the NPG, the PG showed more severe coronal imbalance preoperatively, with CBD of 35.6±22.3 mm and 11.6±7.1 mm respectively; more severe neck tilt and head shift, with neck tilt angle of 17.4°±8.3° and 12.4°±6.9° respectively, and head shift of 22.8±17.7 mm and 13.9±9.8 mm respectively; and a higher proportion of KFS, 65% (11/17) and 34% (13/38) respectively, all with statistical significance ( P<0.05). Postoperatively, the PG showed more severe coronal imbalance compared with the NPG, with 17.3±12.7 mm and 9.6±8.1 mm respectively; more evident residual deformity, with cervical tilt angles of 9.4°±4.6° and 6.4°±5.3° respectively, and head shift of 14.7±7.4 mm and 9.1±5.9 mm respectively; lower correction of Cobb angle in the apical osteotomy region, with rates of 40.1%±15.2% and 50.3%±19.9% respectively; more significant UIV and LIV tilt, with UIV tilt angles of 14.3°±7.4° and 9.8°±5.3° respectively, and LIV tilt angles of 8.1°±5.5° and 4.5°±3.6° respectively, all with statistical significance ( P<0.05). SPG showed only more severe coronal imbalance preoperatively compared with the MPG, with 50.7±31.3 mm and 27.3±9.6 mm respectively; and head shift, with 33.5±25.0 mm and 16.9±11.0 mm respectively, all with statistical significance ( P<0.05). Logistic regression analysis demonstrated a significant correlation between significant preoperative coronal imbalance and postoperative distal scoliosis progression [ OR=1.299, 95% CI (1.101, 1.531), P=0.002]. Five cases (83.3%) in SPG underwent revision surgery with an average follow-up of 25 months, and selecting the LIV down to the stable region was the major revision strategy. Conclusion:Combined KFS, residual cervicothoracic deformities, and tilting of UIV and LIV are key causes, whereas significant preoperative coronal imbalance is an independent risk factor predisposing to the distal curve progression.

Objective:To clarify the characteristics of dynamic change of pelvic incidence (PI) in patients with adult spinal deformity in a longitudinal study, to explore the relationship of PI change and other sagittal parameters, and to investigate the role of PI change in the progression of global sagittal imbalance.Methods:The patients with adult spinal deformity (ASD) who were followed up at our clinic from December 2014 to December 2022 were retrospectively reviewed. All patients were older than 50 years and had a minimum of 2-year follow-up. Full-spine frontal and lateral X-ray films were taken at pre-operation, post-operation, and last follow-up. Radiographic parameters were measured, including Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), regional kyphosis (RK), sagittal vertical axis (SVA), T1 pelvic angle (TPA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). Intraclass correlation coefficient (ICC) was used to evaluate intra- and inter-observers' reliability, of which ICC>0.75 indicated excellent; 0.5< ICC≤0.75 indicated good; ICC≤0.5 indicated poor. Independent t-test, paired t-test and Pearson coefficient correlation were performed for statistical analysis. Results:A total of 30 patients were included in this study with a mean age of 61.93±6.20 years (range 54-72 years). The mean follow-up duration was 37.47±8.57 months (range 25-46 months). ICC test showed an excellent intra- and inter-observer reliability of PI in ASD patients from baseline to last follow-up (inter-observer ICC: 0.917 at baseline and 0.923 at last follow-up; intra-observer ICC: 0.913 at baseline and 0.915 at last follow-up). From first-visit to the last follow-up, PI significantly increased from 44.47°±5.96° to 52.07°±7.42° ( t=13.375, P<0001), PT (22.33°±5.77° vs. 28.07°±8.16°, t=4.268, P=0.001), SVA (40.03±13.34 mm vs. 64.37±27.06 mm, t=5.303, P<0.001), TPA (16.20°±5.02° vs. 27.13°±6.45°, t=13.742, P<0.001) and PI-LL (15.07°±13.92° vs. 29.67°±13.54°, t=10.802, P<0.001) were significantly increased while LL was significantly decreased (29.40°±15.53° vs. 22.40°±16.47°, t=4.814, P<0.001) at last follow-up. Pearson correlation analysis showed that the change of PT ( r=0.659, P=0.008), the change of TPA ( r=0.629, P=0.012), pre-operation PI ( r=0.560, P=0.030), and the last follow-up PI ( r=0.746, P=0.001) were significantly correlated with last follow-up PI. Conclusion:This study suggested that PI could significantly increase during follow-up in ASD patients. The dynamic change of PI may be correlated with the deterioration of sagittal imbalance.

Objective:To compare the clinical outcomes between three-column osteotomy and posterior-column osteotomy for correcting dystrophic kyphoscoliosis secondary to neurofibromatosis type 1 (DKS-NF1).Methods:ALL of 84 patients with DKS-NF1 were retrospectively analyzed, and the average age was 17.7±6.9 years. There were 50 cases with single curve, 18 cases with double curves, and 16 cases with triple curves; kyphosis was found in 42 cases in the thoracic area, 31 cases in the thoracolumbar area, and 11 cases in the lumbar area. The patients were divided into two groups: posterior column osteotomy group and three column osteotomy group based on surgical strategy. The radiographic parameters (including the magnitude of kyphosis, scoliosis, coronal balance distance, etc.) were compared between the two groups before and after surgery, and during the follow-up. The surgical efficacy was also compared based on the spinal correction and complications (such as cerebrospinal fluid leakage, pneumothorax, rod breakage, etc.).Results:The posterior column osteotomy group consisted of 74 patients and the column osteotomy group consisted of 10 patients. The age of patients in the posterior column osteotomy group was significantly younger than that in the three-column osteotomy group (15.8±4.8 years vs. 29.4±10.2 years, t=7.088, P<0.001), and the proportion of preoperative traction in this group was significantly higher than that in the three column osteotomy group (26/74 vs. 0, P=0.027). The apex of kyphosis in the three-column osteotomy group mainly located in the thoracolumbar and lumbar area, significantly higher than that in the posterior column osteotomy group (10/10 vs. 32/74, P=0.001). The magnitude of kyphosis in the two groups were 73.8°±20.9° and 63.1°±21.4° before surgery, respectively ( t=1.506, P=0.136). After surgery, they were corrected to 43.1°±20.9° and 21.1°±22.8°, respectively ( t=3.066, P=0.003), with correction rates of 43.7% ±19.6% and 84.1% ±78.7%, respectively ( t=3.677, P<0.001). At the last follow-up, they were maintained at 46.5°±20.9° and 24.6°±25.5°, respectively ( t=3.016, P=0.003). The Cobb angle of the main curve was corrected from preoperative 83.0°±29.0° and 66.3°±17.7° ( t=1.766, P=0.081) to postoperative 50.6°±20.8° and 40.8°±15.6° ( t=1.436, P=0.155), with correction rates of 38.3% ±16.6% and 39.3% ±12.7% ( t=0.191, P=0.849), respectively. At the last follow-up, they were maintained at 52.3°±20.5° and 43.1°±18.2°, respectively ( t=1.339, P=0.185). The proportion of multi-rod system application and screw density in three column osteotomy group was significantly higher than that in posterior column osteotomy group (8/10 vs. 20/74, P=0.002; 72.0% ±11.3% vs. 61.4% ±14.6%, t=2.173, P=0.033). The incidence of complications in the two groups was 12.2% (posterior column osteotomy group, 9/74) and 20% (three column osteotomy group, 2/10), respectively, with no statistically significant difference ( P=0.613). Conclusion:Three-column osteotomy is mainly used to treat adult kyphosis in DKS-NF1 patients. While the posterior column osteotomy methods were mainly applied in young patients. Most patients can achieve the purpose of deformity correction by posterior column osteotomy alone or combined with anterior complementary fusion. For patients with severe kyphosis, preoperative Halo gravity traction can help to further correct the intraoperative deformities.

Objective:To investigate the correlation between pelvic compensatory capacity and proximal junctional kyphosis (PJK) in patients with adult spinal deformity undergoing spino-pelvic fixation utilizing second sacral alar iliac (S 2AI). Methods:A cohort of 55 patients diagnosed with adult spinal deformity and treated with spino-pelvic fixation utilizing S 2AI between January 2016 and January 2019 was included. The pelvic tilt to pelvic incidence ratio (PT to PI ratio, PTr) was used to categorize patients into high PTr group (PT/PI>0.4) and low PTr group (PT/PI<0.4). Subsequently, patients were further classified into PJK group and non-PJK group based on the occurrence of PJK during the last follow-up. Radiographic parameters such as Cobb angle, coronal balance distance (CBD), global kyphosis (GK), thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), proximal junctional angle (PJA), T 1 pelvic angle (T 1PA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and PI-LL were measured preoperatively, postoperatively, and at final follow-up. The chi-square test was employed to compare the incidence of PJK between the high PTr and low PTr groups at the last follow-up. Additionally, multivariable logistic regression analysis was conducted to identify independent risk factors for PJK. Results:The incidence of PJK was significantly higher in the high PTr group compared to the low PTr group [high PTr group (38%) vs. low PTr group (8%), P<0.05]. Multivariable logistic regression analysis identified pre-operative PTr [ OR=3.274, 95% CI(1.100, 36.973), P=0.035], post-operative PTr [ OR=5.700, 95% CI(1.271, 65.272), P=0.029], and PJA at the last follow-up [ OR=1.274, 95% CI(0.998, 1.624), P=0.009] as independent risk factors for PJK. Conclusion:Patients with higher PTr exhibited poor pelvic compensatory ability, struggled to maintain optimal sagittal balance post-operation, and were at increased risk of developing PJK during follow-up.