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Purpose: This study aimed to examine the changes in thoracolumbar kyphosis (TLK) following correction surgery in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS) and to evaluate its influence on postoperative spinal alignment and clinical outcomes., Methods: Sixty-six patients with Lenke type 5C AIS were included and followed up for a minimum of 5 years after surgery. First, the patients were divided into two groups according to the preoperative TLK angle (Study 1; Kyphosis and Lordosis group). The patients were further classified into two groups according to the presence or absence of postoperative changes in TLK (Study 2; Changed and Maintained groups). Finally, the outcome variables were compared between these groups and analyzed for spinal alignment and clinical outcomes., Results: In Study 1, patients demonstrated a significant kyphotic change in the Lordosis group and a significant lordotic change in the Kyphosis group postoperatively. No statistically significant differences were found between the two groups when comparing the pre- and postoperative coronal and sagittal alignment. In Study 2, there were no statistically significant differences between the Changed and the Maintained groups in each spinal alignment pre- and postoperatively. Each domain of the Scoliosis Research Society 22-item questionnaire remained unchanged at 5 years postoperation., Conclusion: In many patients with Lenke type 5C AIS, TLK changed significantly and approached 0° after surgery. However, the magnitude of the preoperative TLK and the presence or absence of improvement did not affect postoperative spinal alignment. Furthermore, the patients had satisfactory clinical outcomes irrespective of TLK modification., Level of Evidence: III., (© 2023. The Author(s), under exclusive licence to Scoliosis Research Society.)

This study proposes a convolutional neural network method for automatic vertebrae detection and Cobb angle (CA) measurement on X-ray images for scoliosis. 1021 full-length X-ray images of the whole spine of patients with adolescent idiopathic scoliosis (AIS) were used for training and segmentation. The proposed AI algorithm's results were compared with those of the manual method by six doctors using the intraclass correlation coefficient (ICC). The ICCs recorded by six doctors and AI were excellent or good, with a value of 0.973 for the major curve in the standing position. The mean error between AI and doctors was not affected by the angle size, with AI tending to measure 1.7°-2.2° smaller than that measured by the doctors. The proposed method showed a high correlation with the doctors' measurements, regardless of the CA size, doctors' experience, and patient posture. The proposed method showed excellent reliability, indicating that it is a promising automated method for measuring CA in patients with AIS., (© 2023. Springer Nature Limited.)

Background: Since osteopenia has been reported to potentially associated with the progression of scoliosis, bone mineral density (BMD) might have some influences on adolescent idiopathic scoliosis (AIS). However, little is known about longitudinal BMD changes in AIS patients. This study aimed to investigate whether osteopenia in preoperative AIS patients persist at bone maturity, and to evaluate the association between BMD and AIS severity., Methods: We reviewed 61 AIS patients who underwent surgery when they were Risser grade 4 or below and less than 20 years old (16.6 ± 1.9 years), were followed until they were at least 18 years old and had a Risser grade of 5, and followed at least 2 years after the surgery (mean follow-up 4.9 ± 1.7 years). We evaluated radiographical parameters and proximal femur BMD before surgery and at the final follow-up. A BMD of less than the mean minus 1SD was considered as low BMD. Based on preoperative BMD, 37 patients were assigned to normal BMD (N) group (1.02 ± 0.08 g/cm 2 ) and 24 patients to low BMD (L) group (0.82 ± 0.06 g/cm 2 )., Results: All patients in the N-group had normal BMD at the final follow-up. In the L group, 15 patients (62.5%) had low BMD at the final follow-up (L-L group; preoperative 0.79 ± 0.05 g/cm 2 and final follow-up 0.78 ± 0.05 g/cm 2 ). The mean preoperative Cobb angle was significantly larger in the L-L group (67.8 ± 11.2°) than in those with normal BMD at the final follow-up (L-N group, 55.6 ± 11.8°) or the N-N group (50.8 ± 7.6°). Preoperative BMD was significantly negative correlated with the preoperative Cobb angle. The age at surgery and mean preoperative BMI were similar in the L-N and L-L groups., Conclusions: Of AIS patients with low preoperative BMD, 62.5% still had low BMD after reaching bone maturity, and low BMD was associated with the severity of scoliosis., (Copyright © 2022 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

The sacroiliac joint (SIJ) is the largest axial joint in the human body, and the SIJ vacuum phenomenon (SIJ VP) is a common finding in computed tomography studies of the abdomen, pelvis, and lumbosacral spine in adults, with the incidence increasing with age. Adolescent idiopathic scoliosis (AIS) is an abnormal spinal curvature that appears during adolescence and places abnormal stress on the SIJs. This retrospective observational study aimed to investigate the incidence of the SIJ VP in thoracic AIS (Lenke types 1 and 2). Sixty-seven patients with AIS (age: 12-19 years) and 76 controls (age: 11-19 years) were retrospectively analyzed to investigate SIJ VP, subchondral bone cysts, and SIJ degeneration (Eno classification: type 0, no degenerative change; type 1, mild degenerative changes; type 2, substantial degenerative changes; and type 3, ankylosis). SIJ degeneration was defined as type ≥ 2. The association between SIJ VP, cysts, SIJ degeneration, and sagittal/coronal spinopelvic alignment was assessed. SIJ VP (59% vs. 35.5%, P < .01), cysts (32.8% vs. 1.3%, P < .01), and SIJ degeneration (3.2% vs. 2.6%, P = .823) differed significantly between the 2 groups. There were 0 cases of SIJ ankylosis (Eno classification type 3) in both groups. The VP was not correlated with lumbar lordosis, sacral slope, or Cobb angle. All lumbar modifier type C belonged to the VP present group, whereas none to VP absent group. Our results suggest an association between AIS and SIJ VP and SIJ cysts. SIJ VP and SIJ cysts in AIS may be caused and accelerated by abnormal mechanical stress on SIJ due to spinal deformity., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

LBX1 is a gene located near a single-nucleotide polymorphism, rs11190870, which is highly associated with susceptibility to adolescent idiopathic scoliosis. However, the potential involvement of LBX1 in the etiology of this spinal deformity has not been elucidated. In this study, we aimed to determine whether the lack of LBX1 in skeletal muscle results in spinal deformities in mice. We generated mutant mice in which the Lbx1 allele was conditionally excised under the control of a human muscle actin promoter. Mice lacking LBX1 from the skeletal muscle were fertile and available. The mutant mice had hypoplastic forelimbs and weighed less than control animals, but otherwise, there were no overt anomalies. The mice did not exhibit a scoliosis-like spinal deformity; however, they developed moderate kyphosis as they grew old. These observations indicated that LBX1 is involved in limb development and potentially in the maintenance of spinal curvature/alignment in mice., (© 2022 Orthopaedic Research Society. Published by Wiley Periodicals LLC.)

Study Design: Multicenter retrospective study., Objective: This study reports long-term clinical and radiographic outcomes in surgically treated patients with adult symptomatic lumbar deformity (ASLD)., Summary of Background Data: The short-term results of corrective spinal surgery for ASLD are often favorable despite a relatively high complication profile. However, long-term outcomes have not been completely characterized., Methods: A total of 169 surgically treated consecutive ASLD patients (≥50 yr) who achieved minimum 5 year follow-up were included (average 7.5 yr observation window, average age 67±8 yr, 96% female). The subjects were stratified by current age (50s, 60s, and 70s) and compared. Kaplan-Meier analysis was used to estimate the cumulative incidence of unplanned reoperation stratified by age group. Initial and overall direct costs of surgery were also analyzed., Results: The SRS-22 at final follow-up was similar among the three groups (50s, 60s, and 70s; 4.0±0.5 vs. 3.8±0.7 vs. 3.8±0.7, respectively). The overall major complication rate was 56%, and 12% experienced late complications. The cumulative reoperation rate was 23%, and 4% required late reoperation. Patients in their 70s had a significantly higher reoperation rate (33%) and overall complication rate (65%). However, the late complication rate was not significantly different between the three groups (9% vs. 12% vs. 13%). Sagittal alignment was improved at two years and maintained to the final follow-up, whereas reciprocal thoracic kyphosis developed in all age groups. The direct cost of initial surgery was $45K±9K and increased by 13% ($53K±13K) at final follow-up., Conclusions: Long-term surgical outcomes for ASLDs were favorable, with a relatively low rate of late-stage complications and reoperations, as well as reasonable direct costs. Despite the higher reoperation and complication rate, ASLD patients of more advanced age achieved similar improvement to those in the younger age groups., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The impact of ethnicity on the surgery outcomes of adolescent idiopathic scoliosis in the adult (AISA) is poorly understood. This study aimed to compare the surgery outcomes for AISA between the United States (US) and Japan (JP)., Methods: 171 surgically treated AISA (20-40y) were consecutively collected from 2 separate multicenter databases. Patients were propensity-score matched for age, gender, curve type, levels fused, and 2y postop spinal alignment. Demographic and radiographic parameters were compared between the US and JP at baseline and 2y post-op., Results: A total of 108 patients were matched by propensity score (age; US vs. JP: 29 ± 6 vs. 29 ± 7y, females: 76 vs. 76%, curve type [Schwab-SRS TypeT; TypeD; TypeL; TypeN]: 35; 35; 30; 0 vs. 37; 33; 30; 0%)] levels fused: 10 ± 4 vs. 10 ± 4, 2y thoracic curve:17 ± 13 vs. 17 ± 12°, 2y CSVL: 10 ± 8 vs. 11 ± 9 mm). Similar clinical improvement was achieved between US and JP (function; 4.2 ± 0.9 vs 4.3 ± 0.6, p = 0.60, pain; 3.8 ± 0.9 vs 4.1 ± 0.8, p = 0.13, satisfaction; 4.3 ± 0.9 vs 4.2 ± 0.7, p = 0.61, total; 4.0 ± 0.8 vs 4.1 ± 0.5, p = 0.60). The correlation analyzes indicated that postoperative SRS-22 subdomains correlated differently with satisfaction (all subdomains moderately correlated with satisfaction in the US while only pain and mental health correlated moderately with satisfaction in JP ([function: r = 0.61 vs 0.29, pain: r = . 72 vs 0.54, self-image: r = 0.72 vs 0.37, mental health: r = 0.64 vs 0.55])., Conclusions: Surgery for AISA was similarly effective in the US and JP. Satisfaction for spinal surgery among patients in different countries may not be different unless the procedure limits an individual's unique lifestyle that the patient expected to resume., Competing Interests: Declaration of competing interest The authors declare that they have no relevant conflicts of interest. Justin S Smith, Christopher I. Shaffrey, Virginie Lafage, Frank J Schwab, Shay Bess, and Christopher P. Ames received grants from ISSG foundation during the conduct of the study., (Copyright © 2021 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Study Design: This was a retrospective case series of prospectively collected data., Objective: The present study first described the effect of sublaminar tethering (SLT) on proximal junctional failure (PJF) in adult spinal deformity (ASD) surgery., Summary of Background Data: PJF is a devastating complication following ASD surgery. Teriparatide administration and spinous process tethering have been reported as alternatives for the prevention of PJF, but a clinically effective prevention strategy is still a matter of debate., Materials and Methods: We used data from an ASD database that included 381 patients with ASD (minimum 2-y follow-up). Among them, the data of patients who had a severe sagittal deformity and had surgery from the lower thoracic spine (T9-T11) to the pelvis were extracted and propensity score matched by age, sex, body mass index, bone mineral density, curve type, sagittal alignment, and fused level to clarify whether SLT prevented the development of PJF [SLT vs. control (CTR); age: 67±7 vs. 66±8 y, T-score: -1.4±0.7 vs. -1.3±0.6, body mass index: 22±4 vs. 22±5 kg/m2, C7 sagittal vertical axis (C7SVA): 12±7 vs. 11±5 cm, pelvic incidence-lumbar lordosis (PI-LL): 51±22 vs. 49±21 degrees, pelvic tilt (PT): 36±10 vs. 34±10 degrees, level fused: 11±2 vs. 11±2]. Sixty-four patients were matched into 32 pairs and compared in terms of the postoperative alignment and frequency of PJF., Results: Two years postoperatively, C7SVA and PT were significantly larger in the CTR group, while no significant difference in PI-LL was found (C7SVA: 3±3 vs. 6±4 cm, P<0.01, PT: 16±6 vs. 24±9 degrees, P<0.01, PI-LL: 7±9 vs. 11±11 degrees, P=0.22). The proximal junctional angle was significantly greater in the CTR group (proximal junctional kyphosis: 8±8 vs. 17±13 degrees, P<0.01). The incidence of PJF was significantly lower in the SLT group (3% vs. 25%, P=0.03), with an odds ratio of 0.1 (95% confidence interval: 0.0-0.8, P=0.03)., Conclusion: In the propensity score-matched cohort, the incidence of PJF was significantly lower in the SLT group. SLT is a promising procedure that may reduce the risk of PJF in severe ASD surgery., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Multicenter, retrospective cohort study., Objective: The aim of this study was to investigate the occurrence and surgical predictors of postoperative shoulder imbalance (PSI) in Lenke type 2A adolescent idiopathic scoliosis (AIS)., Summary of Background Data: Although several studies have investigated the factors influencing PSI in Lenke type 2 curves, no studies have analyzed PSI-related factors considering upper instrumented vertebra (UIV) and lumbar modifier type simultaneously., Methods: Patients with Lenke Type 2A AIS treated by spinal fusion were retrospectively identified and their data were extracted from six spine centers in Japan. Inclusion criteria were age between 10 and 20 years at surgery, UIV = T2, major curve 40° to 90°, and follow-up for 24 to 30 months after surgery. We analyzed patient characteristics, surgical characteristics, and preoperative and immediate-postoperative radiographic parameters. We defined patients with lower instrumented vertebra (LIV) equal or proximal to the last touching vertebra (LTV) as selective thoracic fusion (STF-LTV) and patients with LIV distal to the LTV as non-STF-LTV. t Tests, Mann-Whitney U test, χ2 tests, Fisher exact tests, and multivariate logistic regression were used for statistical analyses., Results: Among the 99 consecutive patients with a mean follow-up of 25.6 months, PSI was seen in 27 (27.3%) patients immediately after and in 17 (17.2%) patients at 24 to 30 months. The univariate analysis revealed that the significant risk factors of PSI were preoperative radiographical shoulder height, non-STF-LTV, and high main thoracic curve (MTC) correction (immediate-postoperative MTC correction rate: ≥70%), with PSI incidence of 40.0%. The multivariate logistic regression analysis indicated that interaction term of non-STF-LTV and high MTC correction was an independent risk factor for PSI (non-STF-LTV and high MTC correction, odds ratio: 5.167, 95% confidence interval: 1.470-18.159, P = 0.010)., Conclusion: To prevent PSI in Lenke Type 2A AIS patients, surgeons should avoid the combination of non-STF-LTV and high MTC correction in those surgeries with UIV as T2.Level of Evidence: 4., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: A retrospective comparative study., Objective: The aim of this study was to examine the changes in cervical sagittal alignment (CSA) following surgical correction in a patient with Lenke type 5 adolescent idiopathic scoliosis (AIS) and evaluate any possible factors influencing postoperative CSA., Summary of Background Data: Few studies have assessed the association between CSA and thoracic or lumbar sagittal alignment in AIS patients with major thoracolumbar/lumbar curve who underwent posterior correction and fusion surgery., Methods: Sixty-six patients with Lenke type 5 AIS (two males and 64 females, the mean age at surgery of 16.2 years) were included in this study. They were followed up for minimum 5 years after surgery. Multiple linear regression analysis was used to evaluate possible factors influencing the postoperative CSA. To determine the influence of upper end vertebra (UEV) level on postoperative CSA, the subjects were divided into two groups according to UEV level of ≥T9 or ≤T10. The outcome variables were compared between the two groups and analyzed for changes in various spinal sagittal profiles using radiographic outcomes., Results: Multiple linear regression analysis revealed that preoperative T10-L2 kyphosis and LL were significantly correlated with postoperative C2-7 lordosis. However, CSA did not significantly change at 5 years after surgery. Sub-analysis of the cohort revealed that in the UEV ≥T9 group, the mean thoracic kyphosis significantly increased from 20.3° ± 10.6° to 24.0° ± 8.9° and the mean C2-7 lordosis also significantly increased from -12.5° ± 8.3° to -4.3° ± 10.3° at 5-year postoperatively. SRS-22 outcomes were comparable between the groups., Conclusion: We indicated that the CSA was not influenced by surgical correction in most Lenke type 5 AIS patients. However, in a patient whose UEV was located at T9 or higher levels, CSA was influenced through the changes in thoracic kyphosis following posterior correction surgery.Level of Evidence: 4., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Case: A 14-year-old adolescent boy with congenital kyphoscoliosis with T5 hemivertebra visited our hospital complaining gait disturbance. The T5 hemivertebra was resected posteriorly, and kyphosis at T4 to T7 was corrected from 43° to 36°. However, neurological status gradually deteriorated after surgery. Surgery to reduce kyphosis by bending the rods was performed with intraoperative ultrasonography, which resulted in spinal cord decompression and repulsation of the spinal cord. The muscle strength of the lower extremities improved immediately after surgery., Conclusion: Correction surgery for congenital kyphoscoliosis has high risk of perioperative neurological deterioration. Ultrasonography may be a useful tool for monitoring status of the spinal cord., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/B682)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Adolescent idiopathic scoliosis (AIS) is a common disease causing three-dimensional spinal deformity in as many as 3% of adolescents. Development of a method that can accurately predict the onset and progression of AIS is an immediate need for clinical practice. Because the heritability of AIS is estimated as high as 87.5% in twin studies, prediction of its onset and progression based on genetic data is a promising option. We show the usefulness of polygenic risk score (PRS) for the prediction of onset and progression of AIS. We used AIS genomewide association study (GWAS) data comprising 79,211 subjects in three cohorts and constructed a PRS based on association statistics in a discovery set including 31,999 female subjects. After calibration using a validation data set, we applied the PRS to a test data set. By integrating functional annotations showing heritability enrichment in the selection of variants, the PRS demonstrated an association with AIS susceptibility (p = 3.5 × 10 -40 with area under the receiver-operating characteristic [AUROC] = 0.674, sensitivity = 0.644, and specificity = 0.622). The decile with the highest PRS showed an odds ratio of as high as 3.36 (p = 1.4 × 10 -10 ) to develop AIS compared with the fifth in decile. The addition of a predictive model with only a single clinical parameter (body mass index) improved predictive ability for development of AIS (AUROC = 0.722, net reclassification improvement [NRI] 0.505 ± 0.054, p = 1.6 × 10 -8 ), potentiating clinical use of the prediction model. Furthermore, we found the Cobb angle (CA), the severity measurement of AIS, to be a polygenic trait that showed a significant genetic correlation with AIS susceptibility (rg = 0.6, p = 3.0 × 10 -4 ). The AIS PRS demonstrated a significant association with CA. These results indicate a shared polygenic architecture between onset and progression of AIS and the potential usefulness of PRS in clinical settings as a predictor to promote early intervention of AIS and avoid invasive surgery. © 2021 American Society for Bone and Mineral Research (ASBMR)., (© 2021 American Society for Bone and Mineral Research (ASBMR).)

Study Design: A retrospective multicenter cohort study., Objective: The aim of this study was to identify the incidence and risk factors for UPROR within minimum 2-year follow-up in primary definitive fusion for pediatric spinal deformity., Summary of Background Data: Several previous reports have elucidated the incidence of complications after pediatric scoliosis surgery; however, there has been no study that described the incidence and risk factors for unplanned return to the operating room (UPROR) with long-term follow-up in surgery for pediatric scoliosis with every etiology., Methods: We retrospectively extracted data of patients aged <19 years, from 14 institutes in Japan, who underwent primary definitive fusion surgery for spinal deformity between January 1, 2015 and December 31, 2017. The primary outcomes were the incidence of UPROR within the minimum 2-year follow-up period for any reason. Univariate and multivariate logistical analyses were conducted to identify potential risk factors associated with UPROR., Results: We identified 1417 eligible patients (287 males and 1130 females) with a mean age of 13.9 years. UPROR for any reason within minimum 2-year follow-up was identified in 68 patients (4.8%). The most frequent cause for UPROR was implant failure found in 29 patients, followed by surgical site infection in 14 patients, junctional problems in 10 patients, and neurological complications in six patients. The multivariate logistic regression analysis revealed that a diagnosis of kyphosis (odds ratio [OR], 2.65; 95% confidence interval [CI] 1.16-6.04), etiology of congenital or structural type (OR 2.21; 95% CI 1.08-4.53), etiology of syndromic type (OR 2.67; 95% CI 1.27-5.64), and increased operation time of ≥300 minutes (OR 1.81; 95% CI 1.07-3.07) were the risk factors for the incidence of UPROR., Conclusion: The present multicenter study identified for the first time the incidence and risk factors for UPROR with minimum 2-year follow-up after primary definitive fusion surgery for pediatric spinal deformity with every etiology.Level of Evidence: 3., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Case: A 4-year-old girl with spastic gait and hand clumsiness who was diagnosed with cervical myelopathy caused by atlantoaxial dislocation and midcervical severe kyphosis associated with chondrodysplasia punctata (CDP). The patient underwent posterior instrumentation and anterior spinal fusion and successful correction with osseous fusion was obtained 8 months after surgery. In addition, the preoperative neurological symptoms were completely recovered., Conclusion: Owing to the characteristics of CDP, the treatment for the cervical lesion is extremely complicated. Successful stabilization and improvement of the neurological symptom were achieved by combining posterior and anterior fusion with instrumentation in this case., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/B396)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Case: Gorham-Stout disease (GSD) is a rare disorder characterized by progressive localized osteolysis and lymphatic malformation. A 26-year-old woman with GSD presented to our hospital with a Cobb angle of 100° and a kyphosis angle of 88°. Everolimus therapy was initiated to control the disease prior to surgery. After halo-gravity traction for 4 weeks, we performed anterior and posterior spinal fusion. Postoperative computed tomography revealed satisfactory bone union and no significant loss of correction 1 year post-surgery., Conclusion: This case suggests that anterior and posterior spinal fusion combined with everolimus therapy can be a therapeutic option for GSD., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/B395)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Background Context: A previous study examined the short-term (2 years) outcomes of a short fusion strategy for Lenke type 5C curves. This strategy had a little less correction rate with no difference in coronal and sagittal balance and SRS-22 scores to those of a conventional strategy and was superior in operative time and intraoperative bleeding. However, its effectiveness in longer follow-up periods was unknown., Purpose: To assess midterm surgical outcomes of a short fusion strategy for adolescent idiopathic scoliosis (AIS) with Lenke type 5C curve, involving posterior correction and fusion surgery (PSF) using pedicle-screw constructs., Study Design: Retrospective case series., Patient Sample: Twenty-nine patients who underwent PSF for AIS with Lenke type 5C curve with a minimum 5-year follow-up., Outcome Measures: Radiographic parameters and SRS-22., Methods: We compared radiographic parameters and clinical outcomes between patients with an upper instrumented vertebra (UIV) at the end vertebra (EV) (n=12) and those treated by short fusion (S), with a UIV one level caudal to the EV (n=17)., Results: A preoperative mean Cobb angle of 51.9±13.8° was corrected to 11.7±7.7° in the EV group, and an angle of 46.0±6.6° was corrected to 9.3±5.2° in the S group. The correction was maintained in both groups at the final follow-up, and the mean correction loss was 2.8±6.8° in the EV and 6.5±6.5° in the S group (p=.143). The mean correction rate at the final follow-up was not significantly different between the EV (71.4±11.8%) and S (64.9±13.7%) groups (p=.199). A Cobb angle of a thoracic curve was significantly improved immediately after surgery and maintained during the follow-up period in the both groups. Coronal and sagittal balance, thoracic kyphosis, lumbar lordosis, L4 tilt, UIV/LIV tilt, shoulder balance, and SRS-22 had no difference between the two groups., Conclusions: There was no difference in radiographic parameters and SRS-22 between patients treated with a UIV at the UEV and patients treated using a short fusion strategy, in which the UIV was one level caudal to the UEV. The short fusion strategy can be one of the alternatives in PSF for Lenke type 5C curves, at least in 5-year time frame., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Little is known about the effects of posterior tethers on the development of proximal junctional kyphosis (PJK). We evaluated the ability of posterior tethers to the proximal motion segment stiffness in long instrumented spinal instrumentation and fusion using a whole body human FE model. A series of finite element (FE) analysis of long segmental spinal fusion (SF) from the upper thoracic vertebra (T1) or lower thoracic vertebra (T9) to the sacrum with pedicle screws and rods were performed using an entire human body FE model (includes 234,910 elements), and compressive stresses (CS) on the anterior column, and tensile stresses (TS) on the posterior ligamentous complex (PLC) in the upper-instrumented vertebra (UIV) and the vertebra adjacent to the UIV (UIV + 1) were evaluated with posterior tethers or without posterior tethers. The models were tested at three T1 tilts (0, 20, 40 deg.), with 20% muscle contraction. Deformable material models were assigned to all body parts. Muscle-tendon complexes were modeled by truss elements with a Hill-type muscle material model. The CS of anterior column decreased with increasing T1 slope with tethers in both models, while the CS remained relatively large in T9 model compared with T1 model (T1 UIV; 0.96 to 1.56 MPa, T9 UIV; 4.79 to 5.61 MPa). The TS of the supraspinous ligament was markedly reduced in both T1 and T9 models with posterior tethers (11-35%). High vertebral CS on UIV and UIV + 1 were seen in the T9 UIV model, and the TS on the PLC were increased in both UIV models. Posterior tethers may decrease PJK development after SF with a proximal thoracic UIV, while both posterior tethers and vertebral augmentation may be necessary to reduce PJK development with a lower thoracic UIV.

Study Design: Retrospective chart audit., Objectives: This study investigated changes in sagittal alignment in adults after excision of thoracic spinal cord tumors without spinal fixation., Setting: Single-center study at an academic orthopedic department in Japan., Methods: We retrospectively reviewed records for 32 adults who underwent excision of thoracic spinal cord tumors by multilevel laminectomies without fixation. The participants were divided according to whether the tumor was in the upper (T1-4), middle (T5-8), or lower (T9-12) thoracic spine. We analyzed parameters such as age, sex, time in surgery and estimated blood loss, follow-up period, and preoperative and follow-up the Japanese Orthopaedic Association (JOA) scores and radiographs., Results: Postoperative T1-12 kyphotic changes did not correlate with age, the number of resected laminae, or preoperative T1-12 kyphosis. JOA recovery rates were similar regardless of the tumor location. Participants with tumors in the upper thoracic spine had significant postoperative increases in T1-4 kyphosis, T1 slope (p < .05, respectively). In contrast, there were no significant changes in alignment in participants with tumors in the middle or lower thoracic spine., Conclusion: Even without fixation, sagittal alignment did not change after surgery to excise tumors in the middle and lower thoracic spine, indicating that fixation may not be necessary when excising spinal cord tumors in this region. In contrast, postoperative kyphosis may increase when the tumor is in the upper thoracic spine.

Study Design: A propensity-matched comparison of risk factors for proximal junctional failure (PJF), which is a symptomatic proximal junctional kyphosis developing after corrective surgery for adult spinal deformity (ASD)., Objective: To elucidate the role of bone strength for developing PJF., Summary of Background Data: PJF, a devastating complication of corrective surgery for ASD, often recurs even after revision surgery. Most studies of risk factors for PJF are retrospective and have a selection bias in surgical strategy, making it difficult to identify modifiable PJF risk factors., Methods: We conducted propensity-matched comparisons of 113 surgically treated ASD patients who were followed for at least 2 years, to elucidate whether low bone-mineral density (BMD) was a true risk factor for PJF in a uniform population from a multicenter database. Patients were grouped as having mildly low to normal BMD (M group; T-score≧ - 1.5) or significantly low BMD (S group; T-score <  -1.5), and were propensity-matched for age, upper and lower instrumented vertebrae, history of spine surgery, and Schwab-Scoliosis Research Society (SRS) ASD classification. PJF was defined as a ≥20° increase from the baseline proximal junction angle with a concomitant deterioration of at least one SRS-Schwab sagittal modifier grade, or any type of proximal junctional kyphosis requiring revision., Results: PJF developed in 22 of 113 patients (19%). There were 48 propensity-matched patients in the M and S groups (24 in each) with similar parameters for age, body mass index, number of vertebrae involved, C7SVA, pelvic incidence  - LL, and SRS-Schwab type. In this propensity-matched population, the incidence of PJF was significantly higher in the S group (33% vs. 8%, P < 0.01, odds ratio 6.4, 95% CI: 1.2-32.3)., Conclusion: Low BMD was a significant risk factor for PJF in this propensity-matched cohort (odds ratio 6.4). Surgeons should consider prophylactic treatments when correcting ASD in patients with low BMD., Level of Evidence: 3.

OBJECTIVE A number of studies have reported that surgery for cervical intramedullary tumors via the posterior approach can result in postoperative sagittal malalignment of the cervical spine; however, the risk factors remain unclear. The purpose of this study was to investigate the changes in cervical spinal alignment after surgery for cervical intramedullary tumors in adults and to elucidate the risk factors for cervical spinal sagittal misalignment. METHODS Data for the period from April 2001 to December 2011 for all adults who had undergone surgery for cervical intramedullary spinal cord tumors at a single institution were retrospectively analyzed to determine the postoperative changes in cervical spine alignment. Patients younger than 20 years of age and those who required postoperative radiotherapy were excluded from the study. Patients were divided into 2 groups according to tumor location: upper tumor (U) group, in which the central region of the tumor was above the C-5 level; and lower tumor (L) group, in which the central region of the tumor was at or below the C-5 level. Changes in alignment of the cervical spine were measured on plain lateral radiographs. Data on atrophy of the deep extensor muscles (DEMs), tumor location, detachment of the DEMs from the C-2 spinous process, the C2-7 angle before surgery, patient age at surgery, tumor histology, patient sex, tumor size, and number of laminae affected were reviewed for each patient, and the correlation of each of these factors with cervical spinal malalignment was evaluated using statistical analysis. RESULTS The 54 adults eligible for analysis had a mean age of 49.1 years. Ependymoma was the most common cervical intramedullary tumor (63.0%) in this series. In the tumor location U group, the kyphotic angle of the C2-7 spinal segments increased after surgery (-5.8° ± 2.8°). In contrast, in the L group, the C2-7 lordotic angle increased after surgery (6.4° ± 2.6°). In the univariate analysis, atrophy of the DEMs, detachment of the DEMs from the C-2 spinous process, and an upper cervical location of the tumor were identified as factors significantly correlated with the development of cervical spinal kyphosis after surgery. Multiple linear regression analysis revealed the following as risk factors for kyphotic change of the cervical spine after surgery: 1) atrophy of the DEMs after surgery (β = -0.54, p < 0.01), and 2) detachment of the DEMs from the C-2 spinous process (β = -0.37, p < 0.01). CONCLUSIONS Atrophy of the DEMs after surgery and detachment of the DEMs from the C-2 spinous process are directly related to the risk of cervical spinal kyphosis after surgery for cervical intramedullary tumors in adults. Therefore, preservation of the DEMs, especially those attached to the C-2 spinous process, is important for the prevention of kyphotic malalignment of the cervical spine after surgery for intramedullary tumors.

Case: A 12-year-old girl with Crouzon syndrome presented to our hospital with scoliosis (114°) and kyphosis from T8 to T12 (138°). After she had been in halo-gravity traction for 2 weeks, we performed posterior correction and fusion surgery from T3 to L3, with a posterior vertebral column resection of T10. She experienced postoperative respiratory failure and remained on a ventilator for 4 weeks. With rehabilitation, the respiratory function had recovered by postoperative week 8. At the 2-year follow-up, there was no loss of correction or any other complication., Conclusion: Serious perioperative respiratory complications may occur when a patient with Crouzon syndrome is treated surgically.

Study Design: A retrospective, multicenter study., Objective: To identify risk factors for proximal junctional kyphosis (PJK) when treating early-onset scoliosis (EOS) with dual-rod growing-rod (GR) procedure., Summary of Background Data: The risk factors for PJK associated with GR treatment for EOS have not been adequately studied., Methods: We evaluated clinical and radiographic results from 88 patients with EOS who underwent dual-rod GR surgery in 12 spine centers in Japan. The mean age at the time of the initial surgery was 6.5±2.2 years (range, 1.5-9.8 y), and the mean follow-up period was 3.9±2.6 years (range, 2.0-12.0 y). Risk factors for PJK were analyzed by binomial multiple logistic regression analysis. The potential factors analyzed were sex, etiology, age, the number of rod-lengthening procedures, coronal and sagittal parameters on radiographs, the type of foundation (pedicle screws or hooks), the uppermost level of the proximal foundation, and the lowermost level of the distal foundation., Results: PJK developed in 23 patients (26%); in 19 of these, the proximal foundation became dislodged following PJK. Binomial multiple logistic regression analysis identified the following significant independent risk factors for PJK: a lower instrumented vertebra at or cranial to L3 [odds ratio (OR), 3.32], a proximal thoracic scoliosis of ≥40 degrees (OR, 2.95), and a main thoracic kyphosis of ≥60 degrees (OR, 5.08)., Conclusions: The significant independent risk factors for PJK during dual-rod GR treatment for EOS were a lower instrumented vertebra at or cranial to L3, a proximal thoracic scoliosis of ≥40 degrees, and a main thoracic kyphosis of ≥60 degrees.

Study Design: A retrospective case series of patients treated surgically for degenerative lumbar scoliosis (DLS)., Objective: To determine incidence and risk factors of progressive global thoracic kyphosis (pGTK) after surgery for DLS., Summary of Background Data: Sagittal balance affects the surgical treatment of spinal deformity in adults. Little is known about the loss of sagittal balance due to pGTK, or about the risk factors for pGTK, after surgery for DLS., Methods: We reviewed records from a multicenter database of adults with DLS, treated with posterior spinal fusion. Inclusion required an age of 50 years or more at the time of surgery, an upper instrumented vertebra at T9 and below, more than 5 fused segments, and at least 2 years of follow-up. We included 73 patients with a mean age of 68.3 years (range, 51-77 yr) and a mean follow-up period of 3.6 years (range, 2-11 yr). Independent risk factors for pGTK were identified by logistic regression analysis., Results: Significant pGTK, defined as an increase in thoracic kyphosis of more than 10° from before surgery to the time of final follow-up, was observed in 41% of the patients. Loss of the sagittal vertical axis was larger in patients with pGTK than without (4.7 vs. 1.5 cm; P = 0.02). Risk analysis showed larger lumbar lordosis correction in patients with pGTK. Multivariate logistic regression analysis identified an age greater than 75 (odds ratio, 5.53; P = 0.02, 95% confidence interval [1.4-22.4]) and sacropelvic fusion (odds ratio = 2.66, P = 0.02, 95% confidence interval [1.5-11.1]) as independent risk factors for pGTK., Conclusion: The pGTK incidence after surgery for DLS was 41%. Age, sacropelvic fusion, and a larger sagittal correction were identified as pGTK risk factors. Long-term follow-up will provide more data on the clinical impact of pGTK in elderly patients., Level of Evidence: 3.

Severe cervical kyphosis requiring surgical treatment is rare in patients with neurofibromatosis Type 1 (NF1). When it occurs, however, dystrophic changes in the vertebrae make surgical correction and fusion of the deformity extremely difficult. The authors report on 3 cases of severe cervical kyphosis associated with NF1 that were successfully treated with combined anterior and posterior correction and fusion. All patients underwent halo-gravity traction for approximately 1 month prior to surgery to correct the deformity gradually. Posterior correction and fusion were performed with segmental spinal instrumentation consisting of lateral mass screws, lamina screws, pedicle screws, and polyethylene tape for sublaminar wiring. Anterior spinal fusion was performed using a fibula strut to induce solid bone fusion. All patients used a halo vest for postoperative external fixation. Preoperative CT scans showed dystrophic cervical spine changes, and MR images demonstrated extensive neurofibromas outside the cervical spine in all 3 patients. The preoperative kyphotic angles were as follows: Case 1, 140°; Case 2, 81°; and Case 3, 72°; after halo-gravity traction, the kyphosis angles improved to 50°, 55°, and 51°, respectively; and after surgery, they were 50°, 15°, and 27°, respectively. Solid bone union was observed in all patients at the latest follow-up. All three patients experienced postoperative complications consisting of superficial infection, severe pneumonia, and partial dislocation of the distal fibula graft after removing the halo vest, in one patient each. Although dystrophic cervical vertebral changes in these patients with NF1 complicated the correction of severe cervical kyphosis, the use of preoperative halo-gravity traction, a combination of spinal instrumentations, an anterior strut bone graft, and postoperative halo-vest fixation made it possible to correct the kyphosis, maintain the correction, and achieve solid bone fusion.

Background: The purpose of this study was to test the hypothesis that direct vertebral derotation by pedicle screws (PS) causes hypokyphosis of the thoracic spine in adolescent idiopathic scoliosis (AIS) patients, using computer simulation., Methods: Twenty AIS patients with Lenke type 1 or 2 who underwent posterior correction surgeries using PS were included in this study. Simulated corrections of each patient's scoliosis, as determined by the preoperative CT scan data, were performed on segmented 3D models of the whole spine. Two types of simulated extreme correction were performed: 1) complete coronal correction only (C method) and 2) complete coronal correction with complete derotation of vertebral bodies (C + D method). The kyphosis angle (T5-T12) and vertebral rotation angle at the apex were measured before and after the simulated corrections., Results: The mean kyphosis angle after the C + D method was significantly smaller than that after the C method (2.7 ± 10.0° vs. 15.0 ± 7.1°, p < 0.01). The mean preoperative apical rotation angle of 15.2 ± 5.5° was completely corrected after the C + D method (0°) and was unchanged after the C method (17.6 ± 4.2°)., Conclusions: In the 3D simulation study, kyphosis was reduced after complete correction of the coronal and rotational deformity, but it was maintained after the coronal-only correction. These results proved the hypothesis that the vertebral derotation obtained by PS causes hypokyphosis of the thoracic spine.

STUDY DESIGN.: A case report. OBJECTIVES.: To report a case of progressive kyphoscoliosis associated with a tethered cord that was corrected by posterior vertebral column resection after complicated untethering surgery. SUMMARY OF BACKGROUND DATA.: There have been few clinical reports on posterior vertebral column resection conducted for severe deformity associated with a tethered cord. METHODS.: A patient with progressive kyphoscoliosis associated with a tethered cord first underwent untethering surgery, resulting in neurologic deterioration. Posterior vertebral column resection was performed to correct the kyphoscoliosis while shortening the spinal column to prevent the spinal cord from stretch injury. RESULTS.: Good correction of kyphoscoliosis was obtained without further neurologic deterioration. The Cobb angles of scoliosis was 103 degrees before surgery and 25 degrees after surgery (correction rate; 75.7%), and that of kyphosis was 90 degrees and 36 degrees , respectively (correction rate; 60.0%). CONCLUSION.: Correction of progressive kyphoscoliosis associated with a tethered cord can be achieved successfully by posterior vertebral column resection even after complicated untethering surgery.

Object: This retrospective study was conducted to evaluate the prevalence and clinical consequences of postoperative lamina closure after open-door laminoplasty and to identify the risk factors., Methods: Eighty-two consecutive patients with cervical myelopathy who underwent open-door laminoplasty without plates or spacers in the open side (Hirabayashi's original method) were included (62 men and 20 women with a mean age of 62 years and a mean follow-up of 1.8 years). In 67 patients the cause of cervical myelopathy was spondylotic myelopathy, and in 15 it was caused by ossification of posterior longitudinal ligament. Radiographic measurements were made of the anteroposterior diameters of the spinal canal and vertebral bodies from C3-6, and the presence of kyphosis were assessed. Lamina closure was defined as > or = 10% decrease in the canal-to-body ratio at the final follow-up compared with that immediately after surgery at > or = 1 vertebral level. The impact of lamina closure on neck pain, patient satisfaction, Japanese Orthopaedic Association scores, and recovery rates were also evaluated., Results: The mean canal-to-body ratio at C3-6 was 0.69-0.72 preoperatively, 1.25-1.28 immediately after surgery, and 1.18-1.24 at the final follow-up examination. Lamina closure was observed in 34% of patients and was not associated with sex, age, or cause of myelopathy, but was significantly associated with the presence of preoperative kyphosis (p = 0.014). Between patients with and without lamina closure, there was no significant difference in preoperative (9.7 +/- 3.1 vs 10.6 +/- 2.5) and postoperative (13.7 +/- 2.4 vs 13.1 +/- 2.7) Japanese Orthopaedic Association scores, recovery rates (53.9 +/- 29.9% vs 44.3 +/- 29.5%), neck pain scores (3.5 +/- 0.7 vs 3.3 +/- 1.0), or patient satisfaction level (4.0 +/- 1.4 vs 4.8 +/- 1.0)., Conclusions: Lamina closure at > or = 1 vertebral level occurred in 34% of patients. Although patients with lamina closure obtained equivalent recovery from myelopathy in a short-term follow-up, they tended to be less satisfied with surgery compared with those who did not have closure. The only significant risk factor identified was the presence of preoperative cervical kyphosis, and preventative methods for lamina closure, therefore, should be considered for patients with preoperative kyphosis.

Purpose: The objective of this study was to evaluate 2 years post-surgical loss of three-dimensional correction in adolescent idiopathic scoliosis (AIS) patients using multi-planar reconstruction computed tomography (CT). Methods: Twenty-seven AIS patients treated by segmental pedicle screw (PS) constructs were included in this study. Correction in the axial plane was evaluated using the 'relative apical vertebral rotation angle' (rAVR), defined as the difference between the axial rotation angles of the upper instrumented vertebra and the apical vertebra on reconstructed axial CT images. The Cobb angle of the main curve and apical vertebral translation was measured to evaluate the coronal correction. Thoracic kyphosis was also measured for the evaluation of sagittal profile. Measurements were performed before surgery, and 1 week and 2 years after surgery. The relationships between the correction losses and skeletal maturity, and variety of spinal constructs were also evaluated. Results: The mean preoperative Cobb angle of the major curve was 59.1° ± 11.2° before and 13.0° ± 7.2° immediately after surgery. Two years later, the mean Cobb angle had increased significantly, to 15.5° ± 7.8°, with a mean correction loss of 2.5° ± 1.5° ( p < 0.001). The mean preoperative rAVR of 28.5° ± 8.4° was corrected to 15.8° ± 7.8° after surgery. It had increased significantly to 18.5 ± 8.4 by 2 years after surgery, with a mean correction loss of 2.7° ± 1.0° ( p < 0.001). The mean correction losses for both the Cobb angle and rAVR were significantly greater in the skeletally immature patients. The significant correlations were recognized between the correction losses and the proportion of multi-axial screws, and the materials of constructs. Conclusions: Statistically significant loss of correction in the Cobb angle and apical vertebral axial rotation angle (AVR) were recognized 2 years after surgery using PS constructs. The correction losses, especially AVR, were more evident in the skeletally immature patients, and in patients treated with more multi-axial screws and with titanium constructs rather than with stainless constructs. [ABSTRACT FROM AUTHOR]

Cavernous hemangioma consists mainly of congenital vascular malformations present before birth and gradually increasing in size with skeletal growth. A small number of patients with cavernous hemangioma develop scoliosis, and surgical treatment for the scoliosis in such cases has not been reported to date. Here we report a 12-year-old male patient with severe progressive scoliosis due to a huge subcutaneous cavernous hemangioma, who underwent posterior correction and fusion surgery. Upon referral to our department, radiographs revealed a scoliosis of 85° at T6-L1 and a kyphosis of 58° at T4-T10. CT and MR images revealed a huge hemangioma extending from the subcutaneous region to the paraspinal muscles and the retroperitoneal space and invading the spinal canal. Posterior correction and fusion surgery using pedicle screws between T2 and L3 were performed. Massive hemorrhage from the hemangioma occurred during the surgery, with intraoperative blood loss reaching 2800 ml. The scoliosis was corrected to 59°, and the kyphosis to 45° after surgery. Seven hours after surgery, the patient suffered from hypovolemic shock and disseminated intravascular coagulation due to postoperative hemorrhage from the hemangioma. The patient developed sensory and conduction aphasia caused by cerebral hypoxia during the shock on the day of the surgery. At present, two years after the surgery, although the patient has completely recovered from the aphasia. This case illustrates that, in correction surgery for scoliosis due to huge subcutaneous cavernous hemangioma, intraoperative and postoperative intensive care for hemodynamics should be performed, since massive hemorrhage can occur during the postoperative period as well as the intraoperative period. [ABSTRACT FROM AUTHOR]

Study Design: Case-control study.Objective: To examine factors influencing cervical alignment after corrective surgery for adult patients with adolescent idiopathic scoliosis (AdIS) SUMMARY OF BACKGROUND DATA.: Corrective surgery for spinal deformity influences postoperative cervical spinal alignment, but changes in the cervical alignment in adults with AdIS are scarcely reported.Methods: We retrospectively examined 85 patients with AdIS who underwent posterior corrective surgery for thoracic or lumbar major curve and were followed up for 2 years. Clinical characteristics, radiographic parameters, and health-related quality of life (HRQOL) were evaluated. Cervical deformity (CD) was defined as one of the following cases: (1) T1 tilt minus C2-C7 angle more than 20°, (2) C2-C7 SVA more than 40 mm, (3) and C2-C7 angle less than -10°. Patients were divided into those with and without CD based on the defined criteria; statistically relevant factors were analyzed.Results: There were 19 patients in the postoperative CD group. The average age at the time of surgery was lower in the CD group (26.5 vs. 31.4). In the CD group, the average preoperative T1 tilt was smaller (1.1° vs. 12.5°), and the C2-C7 angle was kyphotic (-16.1° vs. 3.0°). The average kyphotic angle at thoracic spine (T5-T12) was lower in the CD group preoperatively (12.5° vs. 19.5°) and postoperatively (15.2° vs. 20.8°). HRQOL outcomes were comparable between the groups. Of the patients with preoperative CD, 51.5% (n = 17) maintained their deformity at the final follow-up, and baseline C2-C7 angle was lower than those who converted to non-CD following surgery (n = 16) (-17.0° vs. -10.3°).Conclusion: More than half of the patients with baseline CD maintained their cervical malalignment postoperatively. Patients with postoperative CD presented cervical kyphotic and thoracic hypokyphotic alignments before surgery. Because CD has the potential to lead to cervical degeneration, careful follow-up observation is necessary for these young patients.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]

Study Design: A multicenter retrospective case series of patients treated surgically for adult spinal deformity (ASD).Objective: The aim of this study was to compare clinical outcomes between propensity score matched ASD patients with or without drop body syndrome (DBS).Summary Of Background Data: DBS is an extreme primary sagittal-plane deformity often seen in Asian countries. Although the importance of sagittal alignment is widely recognized, surgical outcomes for deformities purely in the sagittal plane are poorly understood.Methods: This study included 243 consecutive patients (age 66 ± 17 years; range 22-78) who were treated surgically for ASD and were followed at least 2 years (mean follow-up 3.7 ± 2.3 years). DBS was defined as a primary lumbar kyphosis with PI-LL >40°, Cobb angle <30°, and multifidus cross-sectional area <300 mm. DBS patients were matched with non-DBS patients by propensity scores for age, gender, lowest instrumented vertebra (LIV) level, and number of levels fused. Demographics, radiographic findings, and clinical outcomes were compared between DBS and non-DBS patients.Results: Of 243 patients with ASD, 34 had DBS (14%); 28 of these were propensity-matched with ASD patients without DBS. Baseline bone mineral density (BMD), body mass index (BMI), and frailty were similar in DBS and non-DBS patients. Baseline sagittal alignment was worse in DBS than in non-DBS patients [C7SVA 14 ± 5 vs. 8 ± 5 cm; pelvic incidence (PI) - lumbar lordosis (LL) 60 ± 14 vs. 36 ± 20°], and scoliosis research society (SRS)22 scores were also worse for DBS patients (2.5 ± 0.6 vs. 2.9 ± 0.8). Although DBS patients had more complications (20 DBS vs. 16 non-DBS), the clinical outcomes were similarly improved in both groups after surgery. At the 2-year follow-up, the spinopelvic malalignment was worse in DBS than non-DBS patients (PI-LL 17 ± 16° vs. 8 ± 13°, P < 0.05).Conclusion: DBS affected 14% of 234 ASD patients. Although DBS patients had inferior baseline SRS22 scores than non-DBS patients, ASD surgery resulted in similar clinical improvement in both groups. Future studies should examine the influence of lifestyle and genetics on clinical outcomes after surgery for DBS.Level Of Evidence: 3. [ABSTRACT FROM AUTHOR]